Arowana & Gar case method: 50 questions

Saturday morning, you notice that your 60 cm silver arowana, in its third year with you, has its right eye pointing downward and it will not return to normal. It eats as usual and swims normally. Lately you have mostly fed sinking food dropped to the bottom; the tank sits on the floor of a bright living room where people often walk past. Nitrite is zero and the water tests fine.

Which is the most appropriate response to this condition?

1. Push the eyeball back into place with your finger and hold it there
2. It is an emergency, so rush the fish to an after-hours animal hospital right now
3. Feed floating food, cover the sides of the tank, and consult a vet within a few days
4. It is fine to leave it alone; do nothing until it goes back on its own

AnswerC. Feed floating food, cover the sides of the tank, and consult a vet within a few days

ExplanationDrop eye is common in silver arowanas and is thought to involve fat deposits behind the eye and the habit of looking downward. It is not painful or life-threatening, so an after-hours emergency visit is unnecessary, but once it progresses it is hard to reverse. Feed floating food to reduce bottom-pecking, cover the sides and bottom of the tank so the fish looks upward, and consult a fish-capable vet within a few days. Pushing the eyeball back injures the eye and can cause blindness or infection. Leaving it allows progression.

IssuesDropping sinking food to the bottom and keeping a floor-level tank with people walking below the fish's eye line kept its gaze pointed downward. The owner did not know the early signs of drop eye, so it took time to notice the abnormality.

ImprovementFeed at the surface and place the tank above eye level, or cover the sides and bottom with dark panels. Check both eyes and body color at every feeding, and photograph any abnormality so progression can be compared. Limit high-fat foods.

Sunday evening, the edges of the gill covers of your Asian arowana, now 45 cm long, are curling outward and the red gill tissue is visible. It is breathing fast and restlessly pacing along the glass. The tank is 90 x 45 cm and water changes are done about once a month. A nitrite test shows a pale red. It is still eating.

Which action should take highest priority?

1. Improve water quality with a water change and plan an urgent move to a larger tank
2. You heard that trimming the gill covers with scissors fixes it, so cut them yourself
3. Increase the food to build its strength and watch
4. Add double the labeled dose of an over-the-counter fish medication to sterilize the water

AnswerA. Improve water quality with a water change and plan an urgent move to a larger tank

ExplanationGill curl is mainly caused by water-quality and environmental stress such as a cramped tank, insufficient water changes, and high temperature; a 90 cm tank is clearly too small for a 45 cm arowana. Since nitrite is detected, first do a one-third water change with temperature-matched water, raise the water-change frequency to weekly, and urgently plan a move to a 180 cm-class tank. Trimming the gill cover requires anesthesia and specialist skill; doing it yourself causes heavy bleeding and infection. More food worsens water quality, and overdosing medication damages the gills and worsens breathing difficulty. If there is no improvement, see a vet within a few days.

IssuesNo tank sized for the fish's growth rate had been prepared, and monthly water changes could not keep up with a large fish's waste output. There was no habit of testing nitrite, so the problem went unnoticed until the obvious sign of gill curl appeared.

ImprovementMake a weekly one-third water change and weekly nitrite and nitrate tests routine. At purchase, plan an adult-size tank (at least 180 x 60 x 60 cm) and floor reinforcement, and set it up while the fish is still a juvenile. Check the shape of the gill covers daily, and review the environment as soon as they begin to curl.

A November night: your 50 cm silver arowana has several white spots on its pectoral fins and flanks and is rubbing its body against the driftwood. A week ago you tipped feeder fish straight from the bag into the tank. You have found that the water temperature drops to 22°C at night. It is still eating.

Which is the most appropriate first action?

1. Remove the white spots one by one with tweezers
2. Dilute a human disinfectant and add it to the tank
3. Add more feeder fish to build its strength
4. Stabilize the water temperature at 26°C or above, stop adding live food, and consult a vet

AnswerD. Stabilize the water temperature at 26°C or above, stop adding live food, and consult a vet

ExplanationWhite spot (ich) is caused by a parasite and is often triggered by a temperature drop and the addition of unquarantined live food. Check the heater setting and capacity, stabilize the water at 26°C or above, stop adding live food, and consult a fish-capable vet about the choice of medication. Arowanas can be sensitive to medications; self-prescribed medicated baths or human disinfectants damage the gills and can be fatal. White spots cannot be removed physically and attempting it injures the fish. Adding more live food only brings in more parasites. Consult the same day or the next.

IssuesAdding live food without quarantine introduced parasites, and an undersized heater let the night temperature drop, lowering immunity. The owner did not know the early sign of white spot (rubbing) and did not notice until the spots were visible.

ImprovementObserve live food and new fish in a separate container for two weeks before using them. Run two heaters with ample capacity for the water volume, and log the night temperature with a min-max thermometer. Suspect white spot as soon as the fish rubs or clamps its fins, and consult early.

A January morning: your 70 cm silver arowana is motionless near the bottom and will not open its mouth when food is dropped in. Its color is pale and its gills move slowly. The thermometer reads 21°C and the heater's indicator light is off. It ate normally until yesterday. There is only one heater in the tank.

Which is the most appropriate first action?

1. Assume a change of food will get it eating and add live food
2. Replace the heater and raise the temperature gradually, 2–3°C per day, to 26°C or above
3. Add hot water immediately and rush the temperature up to 30°C
4. If it will not eat, do not force it; just watch for a week

AnswerB. Replace the heater and raise the temperature gradually, 2–3°C per day, to 26°C or above

ExplanationArowanas are tropical fish; below 24°C their metabolism drops, causing food refusal and lowered immunity. The cause is a temperature drop from heater failure, so swap in the spare heater and slowly bring the water back to 26°C or above at about 2–3°C per day. Hot water or rapid heating causes fatal temperature shock. Adding live food when the fish cannot digest in the cold leads to indigestion and fouled water. Leaving it for a week exhausts the fish and invites secondary infection. If it still does not eat two or more days after the temperature recovers, or its belly swells, see a vet the same day.

IssuesWith only one heater there was no way to notice a failure, and checking the water temperature in winter was not a habit. The basic step of considering temperature and water quality first when a fish stops eating had not been learned.

ImprovementRun two heaters, mount the thermometer where it is easy to see, and check it every morning. Keep a spare heater and thermostat on hand. Consider a thermometer or smart sensor that alarms when the temperature leaves the set range, and test everything before winter.

An April night: the belly of your 40 cm Asian arowana is swollen on both sides and its scales stand out like a pinecone. There are also small red spots on the body surface. It has not eaten for three days. The tank is 150 cm, but since last month there has been a lot of uneaten food and no water change for two weeks.

Which is the most appropriate first action?

1. Do a one-third water change with temperature-matched water, take photos, and consult a fish-capable vet the same day
2. Press on the belly to squeeze out the accumulated fluid
3. Mix an antibiotic you found online into the food
4. Since the belly is swollen, add a large amount of salt to fix it by osmosis

AnswerA. Do a one-third water change with temperature-matched water, take photos, and consult a fish-capable vet the same day

ExplanationRaised scales, abdominal fluid, and red spots are typical of internal disease from bacterial infection such as Aeromonas, triggered by poor water quality and leftover food. First improve water quality with a one-third temperature-matched water change, photograph the symptoms, and consult a vet the same day. Pressing on the belly damages the organs and does not drain the fluid. Self-administered antibiotics risk resistance and toxicity and require a vet's judgment. Large amounts of salt put severe stress on an arowana and do more harm than good. This disease progresses quickly, so do not put off the visit.

IssuesDespite ongoing leftover food, water changes were skipped for two weeks, creating an environment where bacteria multiply. The fish was left for three days after it stopped eating, and the problem was not noticed until the severe sign of raised scales appeared.

ImprovementRemove uneaten food right after feeding, and keep to weekly water changes and nitrite tests. If the fish skips even one feeding, test the water; if it continues two days, make that the trigger to consult a vet. Find a fish-capable vet in advance and post the contact details next to the tank.

Three days after jumping out of the tank, your 55 cm silver arowana's tail fin edge is cloudy white, and the torn part is getting shorter as if dissolving. It is lively but swims with its fins clamped. Water temperature is 28°C. An abrasion from scraping on the floor during the jump remains on its flank. You have not tested the water.

Which is the most appropriate response at this stage?

1. Cut off the white part of the fin with scissors
2. Apply a human ointment to the wound
3. Test the water, keep it in top condition with water changes, and see a vet within a few days if it worsens
4. Cloudy fins heal on their own, so do nothing

AnswerC. Test the water, keep it in top condition with water changes, and see a vet within a few days if it worsens

ExplanationThis is early fin rot: a bacterial infection of the fin tears from the jump, and keeping water quality at its best is the foundation of treatment. Test nitrite and nitrate, do temperature-matched water changes, and reduce leftover food so bacteria do not multiply. If the white clouding spreads or the red swelling of the flank wound progresses, see a vet within a few days to discuss medication. Cutting the fin yourself causes bleeding and spreads infection. Human ointment washes off immediately in water and its ingredients can be harmful to fish. Left alone, the fin can rot to the base and fail to regrow.

IssuesAfter the jump, wound monitoring and water-quality management were not thorough, allowing infection. The owner lacked the knowledge that fin rot is closely tied to water quality.

ImprovementFor two weeks after a jump, increase water changes and photograph the wounds daily to compare progress. Prevent recurrence with weights and a lock on the lid. Use spreading fin clouding or tearing, or loss of appetite, as the trigger for a vet visit.

1 a.m. in August: your 65 cm silver arowana has its mouth out of the water, gasping, and its gills are moving very fast. Room temperature is 32°C, water temperature 33°C. The aeration has gone silent, and the pump is hot to the touch. The fish is starting to tip onto its side. A spare pump is in the closet.

Which is the most appropriate first action?

1. Dump a large amount of ice directly into the tank to chill it fast
2. Run the spare air pump to supply oxygen and start cooling with a water change using water within 2°C of the tank
3. Wait until morning and call the vet
4. Take the fish out and move it to a bucket of tap water

AnswerB. Run the spare air pump to supply oxygen and start cooling with a water change using water within 2°C of the tank

ExplanationHigh water temperature reduces dissolved oxygen, and the stopped air pump has pushed the fish into hypoxia. Immediately supply oxygen with the spare or a battery-powered air pump, and while doing a water change with slightly cooler water no more than 2°C below the tank, bring the temperature down with a cooling fan. Dumping ice in causes localized rapid chilling and temperature shock. Waiting until morning means death from hypoxia. A bucket of undechlorinated tap water adds chlorine poisoning on top of hypoxia. If the fish is on its side or breathing weakly, contact a fish-capable emergency vet even at night.

IssuesThere was no spare unit for a pump overheating in midsummer, and no summer cooling (fan or chiller) had been set up. The owner lacked the basic knowledge that high water temperature causes hypoxia.

ImprovementKeep a spare air pump and a battery-powered pump on hand, and install a cooling fan or chiller before summer to keep the water at 30°C or below. Inspect pumps regularly, and consider running the air conditioner continuously in rooms where the night temperature rises.

Your 60 cm Asian arowana, kept for five years, has been passing thin white feces for the past week and its belly is slightly swollen. It has been fed only crickets, generously, every day. It is sluggish and increasingly stops near the bottom. Water temperature 28°C, nitrite zero, water quality normal. No fasting day had been set.

Which is the most appropriate response?

1. Increase the crickets further to build its strength
2. Raise the water temperature to 34°C to warm its belly
3. Leave it and wait for the feces to return to normal
4. Stop feeding for now, photograph the feces and belly, and consult a vet the same day

AnswerD. Stop feeding for now, photograph the feces and belly, and consult a vet the same day

ExplanationThin white feces, a swollen belly, and reduced activity are typical signs of indigestion, internal disease, or parasites, triggered by a one-sided, heavy diet of nothing but insects. First stop feeding to rest the gut, photograph the feces and belly, and consult a fish-capable vet the same day. More food adds strain to the intestine, and 34°C is dangerous due to hypoxia and an overdriven metabolism. Left alone, it may progress to abdominal fluid or intestinal blockage. Bringing a fecal sample can help with testing, so collect one for the consultation.

IssuesA one-sided diet of large daily amounts of crickets alone, with no weekly fasting day, overloaded the internal organs. The early sign of a change in feces was missed for a week.

ImprovementMake prepared food the staple and diversify with insects and frozen shrimp as supplements. Feed adults once every one to two days with one fasting day per week. Observe the color and shape of feces daily, and make two days of white or thin feces the trigger for a vet consultation.

In May you added a newly bought bichir to the 180 cm tank on the day of purchase. Five days later, your 70 cm silver arowana is rubbing itself violently against the driftwood and the bottom, darting around and then stopping suddenly. Its fins are clamped and it is breathing fast. No white spots are visible, but it is moving only one gill.

Which is the most appropriate first action?

1. Isolate the new fish in a separate tank, change the water, and have the arowana's gills examined at a vet
2. Remove all the driftwood and substrate to stop the rubbing
3. Assume it is nothing and watch for two weeks
4. Add yet another fish to distract it

AnswerA. Isolate the new fish in a separate tank, change the water, and have the arowana's gills examined at a vet

ExplanationRubbing, one-sided gill movement, and sudden darting after an unquarantined new fish strongly suggest gill or skin parasites such as Gyrodactylus or Dactylogyrus. Isolate the new fish, stabilize the environment with a temperature-matched water change, and have a vet who can do a gill mucus scrape confirm the parasite and choose a medication. Removing the driftwood does not reduce parasites, and two weeks of waiting lets gill damage progress. Adding fish increases hosts and spreads the infestation. See a vet within a few days as a rule, but the same day if breathing distress is severe.

IssuesThe purchased fish was put into the main tank the same day without quarantine, bringing in parasites. The owner did not understand that rubbing and one-sided gill breathing are early signs of parasitic disease in arowanas.

ImprovementAlways observe new fish in a separate tank for two to four weeks before introducing them. Since tankmates themselves stress an arowana, consider keeping it alone as the default. Make uneven gill movement, rubbing, or clamped fins the trigger for same-day water testing and a vet consultation.

Your 80 cm spotted gar, kept under a permit since before 2018, rises to the surface every few minutes, opens its mouth, and returns to the bottom, over and over. It eats well and its color is good. Water temperature 27°C, aeration running. Nitrite zero and the water is clear. The owner is worried about oxygen deprivation.

Which is the most appropriate judgment of this behavior?

1. It is hypoxia, so take the fish out and blow oxygen directly on it
2. It is sick, so add fish medication
3. Gars breathe air using the swim bladder, so with normal water quality this is normal behavior; keep observing
4. Lower the lid to the water surface so it cannot reach the air

AnswerC. Gars breathe air using the swim bladder, so with normal water quality this is normal behavior; keep observing

ExplanationGars use the swim bladder like a lung and regularly gulp air at the surface. If the fish is eating and its color, water quality, and aeration are normal, this behavior is normal and needs no treatment. However, if the frequency suddenly increases, the gills move fast, and the fish cannot leave the surface, suspect hypoxia or gill disease and test the water and consult a vet. Taking the fish out of the water causes severe stress and gill damage. Medicating without a known cause is harmful. Lowering the lid to the surface prevents air breathing and risks suffocating the gar.

IssuesBasic knowledge of the species' physiology (air breathing) was lacking, so normal behavior could not be distinguished from illness. Understanding of the equipment requirement to maintain an air gap was also insufficient.

ImprovementLearn the species' biology and record its normal surfacing frequency as a baseline. Always keep an air gap between the water surface and the lid, and use a lid that covers the whole tank without sealing it. Treat a sudden rise in frequency or persistent gasping as abnormal, and respond with water testing and a vet visit.

Your 65 cm silver arowana, kept for two years in a 120 x 45 cm tank, bends its body into a sharp angle at every turn. Lately its back looks slightly bent when viewed from the side, and it bumps into the glass more often. It is fed prepared food only. Nitrite zero, water temperature 28°C.

Which is the most appropriate response to this situation?

1. Mix a large amount of calcium supplement into the food to strengthen the bones
2. Straighten the bent body by hand
3. Keep it in this tank until it stops growing
4. Move it urgently to a tank of 180 cm or more and consult a vet about the progression of the deformity

AnswerD. Move it urgently to a tank of 180 cm or more and consult a vet about the progression of the deformity

ExplanationIn a tank less than twice the body length, the strain of bending sharply at every turn continues and leads to spinal deformity and a shortened body. Once it progresses it will not reverse, so move the fish urgently to a tank of at least 180 x 60 x 60 cm and consult a vet about the degree of deformity and nutrition. Large calcium additions upset the nutritional balance and foul the water. Straightening by hand damages the spine. Staying in a cramped environment until growth stops locks in the deformity and often brings gill curl and drop eye as well.

IssuesThe owner did not anticipate the growth of a fish that reaches nearly 1 m as an adult and kept it in a 120 cm tank for two years. They did not know that bending to turn is a precursor of deformity, and overlooked the collisions with the glass.

ImprovementBefore buying, learn the adult size and the tank and floor reinforcement required, and prepare the final tank while the fish is a juvenile. Move it before its body length exceeds the tank's depth. Photograph how the body bends on turns and the line of the back once a month, and consult early if anything changes.

A March night: the surface of both eyes of your 50 cm Asian arowana is cloudy white and it is bumping into the walls as it swims. It responds poorly to food. A week ago you cleaned the filter, replaced all the media with new, and swapped out the substrate. A water test detects ammonia and nitrite.

Which is the most appropriate first action?

1. Wipe the eyes with a cotton swab to remove the cloudiness
2. Do a one-third water change with temperature-matched water, repeat the next day, and consult a vet while monitoring the water
3. Turn the lights up to ease the strain on the eyes
4. Salt and medication work on cloudy eyes, so add double the labeled dose

AnswerB. Do a one-third water change with temperature-matched water, repeat the next day, and consult a vet while monitoring the water

ExplanationReplacing all the filter media wiped out the filter bacteria, and the resulting rise in ammonia and nitrite has chemically damaged the eyes and gills. First do a one-third water change with temperature-matched water, then keep changing water from the next day on while testing, bringing ammonia and nitrite close to zero. Clouding of both eyes can involve keratitis or infection, so see a vet within a few days if it does not improve. Wiping the eyes with a swab scratches the cornea and spreads infection. Stronger lighting is pointless. Doubling medication or salt damages an arowana's gills and kills off more filter bacteria.

IssuesNot knowing the basic rule of rinsing media lightly in tank water, the owner replaced everything and lost the filter bacteria. With no habit of testing after cleaning, the ammonia rise went unnoticed until the eyes clouded.

ImprovementNever replace all the media at once; rinse it lightly in tank water and replace it in portions over several weeks. Test ammonia and nitrite daily after any major cleaning. Include eye clarity in daily observation, and make any clouding the trigger for same-day water testing and a water change.

At 7 a.m. you find your 60 cm silver arowana lying on the floor. The edge of the lid had shifted. Its skin is starting to dry, but the gill covers are moving slightly. Dust and grit are stuck to it. You do not know when it jumped. The family is asleep and you are handling this alone.

Which is the most appropriate first action?

1. Lift it with wet hands or a wet towel, return it to the tank, and turn the aeration to maximum
2. Decide it cannot be saved and bury it
3. Grab it with dry hands, rinse the grit off with tap water, then return it
4. Hold it over the tank and see whether it starts swimming on its own

AnswerA. Lift it with wet hands or a wet towel, return it to the tank, and turn the aeration to maximum

ExplanationIf the gills are moving there is a chance of recovery, so support the body with wet hands or a wet towel, return it quickly to the tank, and turn aeration to maximum to move water through the gills. Wet hands are used to avoid stripping the slime coat. Dry hands damage scales and mucus, and rinsing with chlorinated tap water irritates the gills. Holding it at the surface wastes time. Even if it looks dry, do not give up; fish sometimes recover once returned. Afterwards keep it dark and quiet, photograph the wounds, and see a vet the same day if breathing is weak.

IssuesThe edge of the lid had shifted and there was no weight or lock. Because a nighttime jump is found late, the owner underestimated that securely fixing the lid is the only prevention. Debris on the floor also raised the risk of wound infection.

ImprovementCover the entire tank with the lid with no gaps, and always add a weight or lock. Lower the water level several centimeters below the lid to reduce jumping momentum. Do not switch lights off abruptly at night, and tell the family not to tap on the tank. Keep the floor clean at all times.

At night, the moment you switched the room lights on suddenly, your 55 cm silver arowana slammed into the lid. Since then its mouth stays half open and will not close, and the lower jaw looks slightly off-center. Food dropped in does not go into its mouth. Bleeding is slight and it can swim. The underside of the lid was still bare, hard acrylic.

Which is the most appropriate response to this situation?

1. Push the jaw back into position by hand
2. Force food into its mouth with tweezers
3. Keep water quality at its best without touching the fish, suspect a jaw fracture, and see a vet the same day
4. It will heal eventually, so watch for a month

AnswerC. Keep water quality at its best without touching the fish, suspect a jaw fracture, and see a vet the same day

ExplanationA mouth that will not close and a displaced jaw after a collision suggest a jaw fracture or dislocation, which the fish often cannot heal on its own. Do not handle it; keep water quality at its best to prevent infection, and consult a fish-capable vet the same day. Pushing the jaw yourself worsens the fracture and damages nerves and vessels. Forcing food in widens the wound and risks aspiration or choking. A month of waiting leads to wasting from the inability to eat and a permanent deformity. Bring video and an account of the collision to the visit.

IssuesSwitching lights on abruptly in the dark startled the fish, which leapt and hit the lid. There was no understanding of an arowana's habit of jumping straight up when startled, and no padding had been fitted under the lid.

ImprovementTurn lights on and off in stages, switching the room lights on before the tank lights. Fit soft padding to the underside of the lid and keep the water level several centimeters below it. After any collision, always check the mouth, jaw, and eyes; if the mouth will not close, see a vet the same day.

Sunday noon: your 45 cm Asian arowana was startled and crashed into the corner of the driftwood, tearing off three scales on its flank and exposing white skin. Bleeding is slight and it swims normally. The driftwood had been left in place with its sharp corners. Nitrite zero, water temperature 28°C. It was startled because a family member stood up suddenly in front of the tank.

Which is the most appropriate first action?

1. Take the fish out and apply antiseptic to the wound
2. Pick up the lost scales and stick them back on
3. Add double the labeled dose of fish medication as a precaution
4. Remove the sharp driftwood, keep water quality at its best with water changes, and photograph the wound to track it

AnswerD. Remove the sharp driftwood, keep water quality at its best with water changes, and photograph the wound to track it

ExplanationLost scales usually regrow within a few weeks if water quality is good. Remove the driftwood that caused it, keep the water at its best with temperature-matched changes to prevent infection, and photograph the wound to compare progress. Taking the fish out makes things worse through stress and slime-coat damage, and antiseptic washes away instantly in water, doing nothing but irritating. Detached scales will not reattach. Overdosing medication damages the gills. If the wound turns white and cottony, swells red, or appetite drops, see a vet within a few days.

IssuesDriftwood with sharp corners was placed in the tank, and the risk of a startled fish crashing into it was overlooked. There was also too little care about things that startle the fish (sudden movements and vibration).

ImprovementKeep the layout simple; use only driftwood and rocks without sharp edges, or remove them. Tell the family not to move suddenly or tap in front of the tank. Photograph lost scales, and make clouding or swelling the trigger for a vet visit.

Your permitted alligator gar (1 m long) scraped its snout on the wall a week ago. This morning the wound has a white, cotton-like growth on it that is spreading slightly. It eats but is sluggish. Water temperature 26°C, and there has been no water change for two weeks.

Which is the most appropriate response to this situation?

1. Peel the white cotton off by hand to expose the wound
2. Change the water to improve quality and consult a vet the same day for suspected fungus
3. Raise the water temperature to 35°C to kill the fungus
4. It is eating, so there is no problem; leave it

AnswerB. Change the water to improve quality and consult a vet the same day for suspected fungus

ExplanationA white cottony growth on a wound is typical of water mold (fungus), which develops when poor water quality and a wound coincide. First improve water quality with a temperature-matched water change, then consult a fish-capable vet the same day to decide on treatment and medication. Peeling the growth off widens the wound and leaves hyphae deep in the tissue. Heating to 35°C is fatal through hypoxia and metabolic disruption. Left alone, the fungus spreads into the snout and eyes and the fish becomes unable to eat. Since this is a large designated Invasive Alien Species, transport is difficult, so also consider a house call or consultation by photo and video.

IssuesWater changes were skipped even after the snout abrasion appeared, creating conditions for fungus to grow on the wound. Too little thought was given to tank length and lighting management for a long-snouted gar prone to hitting the walls.

ImprovementAfter an injury, increase water changes and photograph the wound daily. Give a gar a tank at least twice its body length, and dim lights in stages to prevent collisions. Confirm in advance which vet can see large fish and whether house calls are available.

To clean the tank, you tried to scoop your 50 cm silver arowana into another container with a small net. The fish thrashed violently, leapt out of the net, tore a pectoral fin, lost several scales, and fell to the floor. You put it into the container right away, but its gills are moving fast and it is starting to tip onto its side.

Which is the most appropriate next action?

1. Add aeration to the container, keep it dark and quiet while it recovers, and record the torn fin
2. Put it straight back into the main tank and net it again
3. Glue the torn fin together with superglue
4. Since it fell on the floor, rinse its body with tap water

AnswerA. Add aeration to the container, keep it dark and quiet while it recovers, and record the torn fin

ExplanationA fish that has thrashed and fallen is in shock; first add aeration, keep it dark and quiet, and let oxygen reach the gills while it recovers. Photograph the torn fin and lost scales, then return it to the main tank once recovered and keep the water at its best. Netting it again immediately compounds the shock and carries a high risk of death. Glue is toxic and must never be used. Chlorinated tap water damages gills and mucus. If breathing does not recover or it stays on its side, see a vet the same day. Move an arowana with water in a large bag or container, never with a net.

IssuesThe wrong method was chosen: scooping a large fish with a small net. There was no need to remove the fish for cleaning in the first place, and the risks of moving it were not understood.

ImprovementClean with the fish in the tank, limiting the job to water changes and bottom cleaning. When a move is necessary, scoop the fish with its water in a heavy bag or large container and do not use a net. Move with two people, and set up aeration and a lid on the container before starting.

The heater guard had been left off for several days, and now your 60 cm silver arowana has a white, burned-looking band on its flank. You had seen it resting right under the heater several times. The scales on the mark have come off and the surrounding area is red. It is eating.

Which is the most appropriate first action?

1. Turn off the heater and lower the water temperature below 25°C
2. It is a burn, so pour cold water over the affected area
3. Just watch; as long as it does not recur there is no problem
4. Refit the heater guard, keep water quality at its best, record the wound, and consult a vet within a few days

AnswerD. Refit the heater guard, keep water quality at its best, record the wound, and consult a vet within a few days

ExplanationThis is a contact burn from the body touching an unguarded heater, with scale loss and skin necrosis. First refit the guard to prevent recurrence, keep the water at its best with temperature-matched changes to prevent infection, photograph the wound, and consult a vet within a few days. Turning off the heater and letting the water cool lowers immunity and slows healing. Pouring cold water on it only causes temperature shock and has no benefit. Left alone, bacteria or fungus colonize the necrotic tissue and form a deep ulcer. Spreading red swelling or food refusal are reasons to see a vet the same day.

IssuesThe heater guard was left off, and the owner saw the fish resting under the heater without recognizing the danger. Knowledge of burn prevention and early detection was lacking.

ImprovementAlways use a guard on the heater, and if possible place it in the sump or where the fish cannot touch it. Make it a habit to refit a removed guard the same day. Check the flanks daily for color change or scale loss, and photograph burn marks to compare progress.

You keep a silver arowana (60 cm) with a large catfish in a 180 cm tank. At night the catfish bit the arowana's tail fin; part of the fin is missing and a faint trace of blood is in the water. The arowana is stopped in a corner, trembling, with its fins clamped.

Which is the most appropriate first action?

1. Take the arowana out of the water and apply a styptic to the wound
2. Leave it alone and wait for it to settle on its own
3. Separate them immediately with a divider or a separate tank, keep the fish resting in the water, and keep water quality at its best
4. Scold the catfish and chase it around with a net

AnswerC. Separate them immediately with a divider or a separate tank, keep the fish resting in the water, and keep water quality at its best

ExplanationBites from a tankmate will be repeated, so first separate them immediately with a divider or a separate tank to stop the attacks. Stop bleeding in fish by keeping them in the water: left dark and quiet with good water quality, fin bleeding usually stops on its own. Taking the fish out worsens things through stress and slime-coat damage, and styptics are not suitable for fish. Left alone it will be bitten again and the wound will become infected. Chasing the catfish solves nothing and stresses both fish severely. If bleeding does not stop, the wound reaches the fin base, or appetite drops, see a vet the same day.

IssuesTwo strongly territorial large fish were kept together without considering the nocturnal nature of a large catfish. No divider or isolation tank had been prepared for an emergency.

ImprovementKeep arowanas alone as a rule; if keeping tankmates, research compatibility of temperament and activity times, and always have a divider or spare tank ready for separation. Observe behavior at night, and make chasing or fin damage the trigger for immediate separation.

10 p.m.: after slamming into the lid, your 70 cm silver arowana is bleeding red from inside the gill cover. Breathing is shallow and fast, only one gill is moving, and it is starting to tip onto its side on the bottom. The bleeding has not stopped after five minutes. Your regular vet is closed at this hour.

Which is the most appropriate first action?

1. Pack tissue paper into the gill to apply pressure
2. Turn aeration to maximum, keep it dark and quiet, and immediately contact a vet who can see fish at night
3. Watch until morning, then call the vet
4. Take the fish out and rinse the gills with tap water

AnswerB. Turn aeration to maximum, keep it dark and quiet, and immediately contact a vet who can see fish at night

ExplanationPersistent bleeding from the gills may mean a gill laceration or internal injury, and with breathing impairment it is an emergency. Do not touch the gills; turn aeration to maximum to secure oxygen, keep the fish dark and quiet so the bleeding does not worsen, and immediately contact an emergency vet who can see fish at night. Packing tissue into the gill stops breathing and destroys the gill filaments. Waiting until morning carries a high risk of death from blood loss and hypoxia. Taking the fish out and rinsing with tap water is fatal to the gills. Transport in a bag one-third full of water topped with oxygen, kept dark and warm.

IssuesAn environment where a leaping fish could slam into the lid was left uncorrected, leading to serious trauma. No vet who can see fish at night had been identified, delaying the initial response.

ImprovementLower the water level and pad the underside of the lid to reduce collision impact. Confirm in advance which vet can see fish and whether after-hours care is available, and post the contact details next to the tank. Keep heavy bags, an oxygen canister, and a foam box on hand so you can move immediately in an emergency.

The moment you closed the lid after feeding, you pinched the pectoral fin of your 50 cm Asian arowana, which was near the surface, under the edge of the lid. The fish thrashed, the fin tore near its base, and there is slight bleeding. You opened the lid at once, but the fish is sitting motionless in a corner with the fin held against its body. The lid is a single panel that is opened fully at every feeding.

Which is the most appropriate next action?

1. Dim the lights, keep it quiet, keep water quality at its best, and record the bleeding and the state of the fin
2. Scoop the fish out and fix the torn fin with glue
3. Trim the fin evenly from the base with scissors
4. Feed it right away to distract it

AnswerA. Dim the lights, keep it quiet, keep water quality at its best, and record the bleeding and the state of the fin

ExplanationA torn fin stops bleeding if the fish rests in the water, and it regrows if water quality is good. Dim the lights, keep things quiet, keep water quality at its best with temperature-matched changes, and photograph the fin. Scooping it out and using glue is toxic and must never be done. Cutting the fin spreads bleeding and infection, and cutting near the base makes regrowth impossible. Feeding right afterwards causes indigestion and leftover food that fouls the water. If bleeding does not stop, the fin base swells red, or appetite drops, see a vet within a few days.

IssuesThe lid was closed without checking the fish's position, even though it was near the surface right after feeding. A single-panel lid opened fully at every feeding made pinching easy, and no feeding hatch had been fitted.

ImprovementMake it a habit to confirm the fish has left the surface before closing the lid. Fit a small feeding hatch so you can feed without opening the whole lid. Add padding to the lid edge to soften the impact if a fin is ever caught.

While feeding crickets with metal tweezers, your 55 cm silver arowana lunged so hard that the tip of the tweezers stabbed the back of its mouth. A little blood came from the mouth, and since then the fish will not open its mouth even when it sees food. Two days later it still is not eating.

Which is the most appropriate response to this situation?

1. Pry the mouth open by hand to check inside
2. Force food into the mouth with the same tweezers
3. If it will not eat, leaving it for a month will fix it
4. Stop feeding, keep water quality at its best, and see a vet the same day, reporting the two or more days of refusal and the bleeding

AnswerD. Stop feeding, keep water quality at its best, and see a vet the same day, reporting the two or more days of refusal and the bleeding

ExplanationA puncture wound inside the mouth can cause infection and stomatitis, and continued food refusal indicates ongoing pain or damage. Pause feeding to rest the gut and the wound, keep water quality at its best to prevent infection, and see a vet the same day, reporting the two or more days of refusal and the history of bleeding. Prying the mouth open worsens the jaw and the wound. Pushing food in with tweezers widens the wound and risks aspiration. A month of waiting allows wasting and infection to progress. For the visit, record how the injury happened, the amount of bleeding, and the days without food.

IssuesHard metal tweezers were used without considering the force of the fish's lunge. The owner did not understand how violently an arowana strikes food at the surface or the risk of injury inside the mouth.

ImprovementSwitch to round-tipped bamboo or plastic tweezers, or feed by floating food on the surface. Place food on the surface and let go immediately; never keep holding a tool at the moment the fish strikes. Make two days of food refusal the trigger for a vet visit.

On a weekend afternoon, your 5-year-old opened the lid of the 180 cm tank, put a hand in the water, and chased your 60 cm silver arowana around. The fish is agitated, thrashing near the surface and leaping out of the water several times. You noticed only after ten minutes; the child is laughing, saying "the fish is angry."

Which is the most appropriate first action?

1. Put in lots of food to calm the fish
2. Move the child away from the tank, close the lid, dim the lights, and check the fish and the area around the tank
3. Leave the lid open while the fish is thrashing so you can put it back right away if it jumps out
4. Let the child touch the fish more so it gets used to it

AnswerB. Move the child away from the tank, close the lid, dim the lights, and check the fish and the area around the tank

ExplanationAn agitated arowana will jump out of an uncovered tank and suffer fatal injuries from the fall. First move the child away, close and weight the lid, and dim the lights to calm the fish. Then check the mouth, eyes, and scales for injuries and the floor for spilled water. Dumping in food increases agitation and fouls the water. Leaving the lid open raises the chance of a jump. An arowana can bite a child's hand, so putting hands in the tank must be forbidden altogether. If there are signs of collision or continued food refusal, consult a vet.

IssuesThe lid could be opened by a child, with no lock and no family education. The family did not understand the arowana's habit of jumping when startled or the risk of a bite to a child's hand.

ImprovementFit a child-proof lock to the lid and keep anything that could serve as a step stool away from the tank. Tell the whole family not to tap the tank or put hands in it, and watch from a distance. After the fish is agitated, keep it dark and quiet and stay away for at least 30 minutes.

Moving house, you were carrying your 65 cm silver arowana in a heavy bag and dropped it on the stairs. The bag did not break, but the fish is on its side inside it and its gills are moving fast. The destination is still an hour away. The bag is half full of water with no oxygen added. The car interior is 30°C.

Which is the most appropriate next action?

1. Open the bag to refresh the air, keep it dark and warm in a foam box, get there as fast as you can, and return the fish to the tank
2. Shake the bag to rouse the fish
3. Open the bag and stroke the fish by hand to calm it
4. Do nothing and carry it as is for the hour until arrival

AnswerA. Open the bag to refresh the air, keep it dark and warm in a foam box, get there as fast as you can, and return the fish to the tank

ExplanationOn top of the shock of the fall, the bag without oxygen and the heat are driving the fish into hypoxia. Open the bag, refresh the air (ideally with oxygen), reseal it, place it in a foam box kept dark and warm, and get to the destination as quickly as possible to return the fish to its tank. Shaking the bag adds more impact, and stroking by hand strips the slime coat and causes stress. Doing nothing risks death from hypoxia. On arrival, turn aeration to maximum, keep it dark and quiet, check breathing, and see a vet the same day if it stays on its side.

IssuesThe basics of transport (oxygen fill, double bagging, foam box, darkness) were not prepared, and the bag was left in a hot car. One person carried it on the stairs, underestimating the risk of a drop.

ImprovementFor transport, fill a heavy bag one-third with water and the rest with oxygen, double-bag it, and place it in a foam box kept dark and warm. Stop feeding one to two days beforehand to reduce fouling. Carry with two people and keep the car at 26–30°C. Have the destination tank set up in advance.

At midnight, three hours after lights-out, you switched the tank lights on suddenly to clean. Your 60 cm silver arowana was startled, crashed into the wall, lay on its side for a while, then bled slightly from the mouth. It is swimming now, but the corner of its mouth is red and swollen. Its breathing is settling.

Which is the most appropriate first action?

1. Turn the lights off, keep it quiet, and observe the mouth wound and swimming until morning without handling it
2. Feed it right away to check that it can eat
3. Turn the lights on again to examine the fish closely
4. Apply a human antiseptic to the swollen mouth

AnswerA. Turn the lights off, keep it quiet, and observe the mouth wound and swimming until morning without handling it

ExplanationAn arowana startled by sudden light at night panics and slams into the walls or lid, injuring its mouth or jaw. Since it is swimming now, turn the lights off, keep it quiet, and observe the mouth wound, swimming, and breathing until morning without handling it. Feeding right afterwards strains the wound and adds leftover food. Turning the lights on again invites a second crash. Human antiseptic is ineffective in water and harmful. In the morning, if the mouth will not close, it will not eat, or the swelling spreads, see a vet the same day.

IssuesThe owner did not know that a fish is dark-adapted after lights-out and that sudden light is a severe fright. The habit of cleaning late at night was itself disrupting the fish's rhythm.

ImprovementDo cleaning and other work during the day. When turning lights on at night, dim the room lights first, then the tank lights, and dim in stages at lights-out too. Leave a weak night light on to avoid an abrupt change from darkness to brightness.

At night, reaching into the 180 cm tank bare-handed to remove uneaten food, you feel a tingling shock in your fingertips. You can see that the insulation on the old heater's cord is partly stripped. Your 65 cm silver arowana is motionless in a corner with its gills moving somewhat fast.

Which is the most appropriate first action?

1. Put your hand in again to check whether the tingling is real
2. Quickly net the fish out and evacuate it to another container
3. Pull the heater out while it is underwater to inspect it
4. Without touching the water, first unplug all the tank equipment from the outlets to stop the electrical leak

AnswerD. Without touching the water, first unplug all the tank equipment from the outlets to stop the electrical leak

ExplanationAn electrical leak in the water is deadly to people and fish alike; the top priority is to cut the power without touching the water. Unplug every device around the tank, work with dry hands, identify the leaking device, and replace it. Putting your hand in again carries a high risk of electrocution. Removing the fish also requires touching the water and is dangerous. Pulling the heater out underwater risks a shock and, once in air, a heated heater can shatter. After cutting the power, observe the fish's breathing and swimming, and see a vet the same day if it lies on its side or breathes abnormally. While the power is off, supply oxygen with a battery-powered air pump.

IssuesThe heater cord was used without inspecting its deteriorating insulation, and no ground-fault breaker was installed. The habit of reaching into the tank bare-handed meant the risk of electric shock was never considered.

ImprovementConnect the tank equipment to a power strip with a ground-fault interrupter and inspect cords every six months. Replace old heaters after a few years. Wear rubber gloves for any work in the water, and switch equipment off first when possible. Keep a battery-powered air pump on hand.

A job transfer has been decided and you realize you cannot take your permitted 90 cm spotted gar with you. An acquaintance told you "release it in a river and it will thrive in the wild," so you are planning to carry it to a nearby river at the weekend. The tank disposal date is approaching too.

Which is the most appropriate action in this situation?

1. Do as your acquaintance says and release it into a nearby river or pond
2. Release is illegal, so contact the retailer, the Ministry of the Environment's regional office, or the local government to find someone to take it
3. Leave it secretly in front of someone's house and go home
4. Stop feeding it and wait for it to die naturally

AnswerB. Release is illegal, so contact the retailer, the Ministry of the Environment's regional office, or the local government to find someone to take it

ExplanationGars have been designated Invasive Alien Species since 2018; release into the wild and unauthorized transfer or transport are punishable under the Invasive Alien Species Act. Release is not only illegal but destroys native ecosystems. If you can no longer keep it, consult the Ministry of the Environment's regional office, the local government, the retailer, or an aquarium or rescue facility to confirm a lawful recipient and the permit procedures. Abandoning it also constitutes abandonment under the Act on Welfare and Management of Animals. Starving it to death is cruelty and violates the duty of lifelong care.

IssuesThe owner did not understand that keeping a designated Invasive Alien Species carries responsibility for lifelong care and escape prevention. Future life changes such as transfers were not considered at the start, and no information on possible recipients was kept.

ImprovementAt the start of keeping, research and write down the permit conditions, transfer procedures, and whom to contact if you can no longer keep the fish. As soon as a move is decided, consult the regional environment office or the retailer early about whether and how a transfer is possible. Never release it.

In the morning, your cat is sleeping on the acrylic lid of the 150 cm tank, and the lid has sagged in the middle almost to the water surface. Your 55 cm Asian arowana is agitated, leaping at the surface and hitting the lid repeatedly. The cat is also dipping a paw in the water as if going for the fish.

Which is the most appropriate first action?

1. Get the cat down immediately, reinforce and weight the lid, and check the fish's mouth and eyes for injuries
2. The cat will calm down once it gets used to it, so leave it
3. Bang on the tank to scare the cat away
4. Remove the lid so the water surface is exposed and the cat gets scared

AnswerA. Get the cat down immediately, reinforce and weight the lid, and check the fish's mouth and eyes for injuries

ExplanationWhen a cat's weight sags the lid, the fish can jump through the gap or the lid can crack and fall into the tank. First get the cat down, reinforce the lid with a rigid panel, add a weight or lock, and check the agitated fish's mouth, eyes, and scales for injuries. Leaving it invites injury from the cat's paw or a jump. Banging on the tank frightens the fish further into crashing against the walls or lid. Removing the lid makes a jump certain. Asian arowanas are a rare species requiring a registration certificate, and death from a jump cannot be undone.

IssuesThe cat could reach the tank, and the lid's strength and fixing were inadequate. The dangers other pets pose to a tank (lid damage, injury, stress) had not been considered.

ImprovementUse a lid thick enough or metal-framed to bear a cat's weight, and fit a lock. Keep the cat out of the room with the tank, or make the top of the tank impossible for the cat to climb. After the fish is agitated, dim the lights and keep it quiet for at least 30 minutes.

Returning from a three-day trip, you find the filter pump on the 180 cm tank stopped, the water cloudy white and smelly. Your 70 cm silver arowana is gasping near the surface and its color has darkened. The nitrite test shows a deep reddish purple and the water temperature is 29°C. An automatic feeder dropped food every day while you were away.

Which is the most appropriate first action?

1. Fix the pump first and change the water the next day
2. Drain all the water and replace it with fresh water
3. Add aeration, do a one-third water change with temperature-matched water, and do another one-third change a few hours later
4. Add double the labeled dose of a water clarifier to remove the cloudiness

AnswerC. Add aeration, do a one-third water change with temperature-matched water, and do another one-third change a few hours later

ExplanationThe filter outage and daily feeding have sent nitrite soaring, and the fish is poisoned and short of oxygen. First supply oxygen with a battery-powered or air pump, do a one-third water change with temperature-matched water, and repeat another one-third change a few hours later to bring levels down in stages. Waiting until the next day, even after repairing the pump, lets the poisoning progress. A full water change causes temperature and pH shock from the sudden shift and kills off the remaining filter bacteria. Doubling a clarifier does not solve the root cause and can harm the fish. If gasping continues or the fish lies on its side, see a vet the same day.

IssuesThere was no backup for a pump stopping while away, and the automatic feeder kept adding food, accelerating the water fouling. No one was monitoring the tank, and no decision had been made to pause feeding.

ImprovementLarge fish can fast for several days, so stop feeding during trips. Monitor water temperature and power with smart sensors while away, set to alert on anomalies. Keep a spare pump, and arrange for family or friends to check on the tank.

To swap tanks, you were carrying your 50 cm silver arowana in an uncovered bucket when it jumped out and fell onto the wooden floor. It is thrashing violently on the floor and bleeding slightly from the mouth. The new tank is still being filled and its temperature does not match.

Which is the most appropriate next action?

1. Wrap it in a dry cloth and put it in the new tank
2. Wrap it in a wet towel, return it to the original tank water, add aeration, and wait for it to settle
3. Wait for the thrashing to stop before picking it up
4. Put it straight into the new tank even though the temperature does not match

AnswerB. Wrap it in a wet towel, return it to the original tank water, add aeration, and wait for it to settle

ExplanationA fish on the floor is drying out and losing its slime coat, so wrap it in a wet towel or wet hands, return it quickly to its original tank water, add aeration, and let it settle in the dark and quiet. A dry cloth strips mucus and scales. Waiting for the thrashing to stop adds impact injuries and drying. Putting it into a tank with mismatched temperature adds temperature shock. Match the new tank's temperature and water quality to the original first, then move the fish in a lidded container or bag. If mouth bleeding or abnormal swimming continues, see a vet the same day.

IssuesThe basic mistake of carrying a large fish in an uncovered bucket was made, and the fish was moved before the destination was ready. The owner did not understand that an arowana will jump even from very shallow water.

ImprovementPrepare the destination with matched temperature and water quality before moving, and use a heavy bag or lidded container. If using a bucket, always cover it with a lid or towel. Move with two people and lay towels on the floor in case of a fall.

In a hurry, you replaced half the water in the 180 cm tank with untreated tap water. Thirty minutes later, your 65 cm silver arowana swam around wildly, then tilted sideways at the surface with its mouth open, and its gills look red and swollen. White slime is peeling off its body and floating in the water.

Which is the most appropriate first action?

1. Do another water change with tap water to dilute it
2. Do nothing until the cloudiness settles
3. Take the fish out and wash the slime off its body
4. Add the labeled dose of dechlorinator directly to the tank, turn aeration to maximum, and observe

AnswerD. Add the labeled dose of dechlorinator directly to the tank, turn aeration to maximum, and observe

ExplanationChlorine in tap water directly damages the gills and the skin's mucous layer; sudden thrashing and peeling slime after a water change are classic signs. Immediately add the labeled dose of dechlorinator to the tank to neutralize the chlorine, turn aeration to maximum to help the gills breathe, and keep it dark and quiet. Another change with tap water adds more chlorine. Doing nothing lets the gill damage progress. Taking the fish out worsens the slime-coat damage. If breathing does not settle, the fish stays on its side, or gill swelling or clouding persists days later, see a vet.

IssuesDechlorination, the most basic step of a water change, was skipped, and a very large half-volume change was done. The owner did not realize that the habit of skipping steps in a rush can lead to a fatal accident.

ImprovementFix the procedure: dechlorinate the new water in a separate container and match the temperature before adding it. Keep dechlorinator next to the tank along with a measuring cup. Limit a single change to one-third, and postpone the change on days when there is no time.

On a summer night, you sprayed insecticide at a cockroach in the room with the tank. The feeding gap in the lid was open. Twenty minutes later, your 60 cm Asian arowana suddenly went wild, trembling and bumping into the walls, and its gill movement became irregular. The smell of the spray lingers in the room.

Which is the most appropriate first action?

1. Open the windows to ventilate, add activated carbon to the filter, do a one-third water change with temperature-matched water, and increase aeration
2. Seal the lid shut until the fish calms down
3. The spray has nothing to do with the fish, so leave it
4. Spray more insecticide to kill the insect that caused this

AnswerA. Open the windows to ventilate, add activated carbon to the filter, do a one-third water change with temperature-matched water, and increase aeration

ExplanationMost insecticides are highly toxic to fish; airborne ingredients dissolve in through the water surface and cause neurological symptoms. First open the windows to ventilate, add activated carbon to the filter to absorb the chemical, do a one-third water change with temperature-matched water, and increase aeration to ease the strain on the gills. Sealing the lid traps the chemical above the surface. Left alone, it can progress from convulsions to death. More insecticide worsens the poisoning. If trembling or irregular breathing continues, see a vet the same day and give the name of the product used.

IssuesThe owner did not know the danger of using insecticide spray in the room with the tank, and the chemical entered through the gap in the lid. Knowledge that insecticides, air fresheners, and foggers are deadly to fish was lacking.

ImprovementNever use spray insecticides, air fresheners, or foggers in the room with the tank. If they must be used, seal the tank and move the air pump intake to another room, and ventilate thoroughly before restoring things. Keep activated carbon on hand so it can be added to the filter in an emergency.

In a household keeping a permitted male and female gar, greenish eggs were found laid on the bottom of the tank. A 4-year-old, thinking they were "fish eggs," picked some up with a finger, put them in their mouth, and swallowed several. Thirty minutes later the child begins complaining of nausea and stomach pain. The eggs are still in the tank.

Which is the most appropriate first action?

1. They are just fish eggs, so give the child water and watch
2. Put a finger down the child's throat to make them vomit
3. Immediately call an emergency helpline or emergency room, stating that the child ate gar eggs; collect and dispose of the eggs wearing gloves
4. Leave the eggs and try to breed the gars

AnswerC. Immediately call an emergency helpline or emergency room, stating that the child ate gar eggs; collect and dispose of the eggs wearing gloves

ExplanationGar eggs are known to be toxic to mammals including humans, causing vomiting, stomach pain, and other poisoning symptoms. Since the child has eaten them and has symptoms, immediately call an emergency helpline or emergency room and state specifically that the child ate gar eggs. Simply watching is dangerous. Forcing vomiting at home risks aspiration and esophageal injury. Collect the remaining eggs wearing gloves and dispose of them. Breeding of gars as designated Invasive Alien Species is itself prohibited, and leaving the eggs to hatch is a violation of the law.

IssuesThe family did not know that gar eggs are toxic or that breeding designated Invasive Alien Species is prohibited, and a child could reach the contents of the tank. There was no management of the spawning risk from keeping a pair.

ImprovementInform the whole family about the toxicity of gar eggs and the ban on breeding, and fit a locking lid so children cannot reach in. If eggs are found, collect them the same day with gloves and dispose of them according to the permit conditions. Avoid housing a male and female together, or confirm the permit terms with the regional environment office.

Because the filter was dirty, you took out all the media, scrubbed it in tap water, and replaced the sponges with new ones. The next day, the water in the 180 cm tank is cloudy white and your 70 cm silver arowana is gasping at the surface and trembling. An ammonia test shows a high reading.

Which is the most appropriate first action?

1. Wash the filter media thoroughly once more
2. Do a one-third water change with temperature-matched water every day, stop feeding, and wait for the filter to recover while testing ammonia
3. Increase the food to build the fish's strength until the cloudiness clears
4. Add several times the labeled dose of an ammonia-reducing product

AnswerB. Do a one-third water change with temperature-matched water every day, stop feeding, and wait for the filter to recover while testing ammonia

ExplanationWashing the media in tap water and replacing everything killed the filter bacteria, and the resulting ammonia spike is poisoning the fish. Do a one-third water change with temperature-matched water every day, stop feeding to reduce waste, and manage the tank for several weeks while testing ammonia and nitrite until the filter recovers. Washing again loses the remaining bacteria too. More food produces more ammonia, and overdosing products is harmful and does not fix the root cause. If gasping or trembling continues, or the fish lies on its side, see a vet the same day. Consider a bacterial supplement as a supporting measure.

IssuesThe owner did not know the basic fact that the filter media houses the bacteria that maintain water quality, and washed it in tap water and replaced it all. There was no habit of testing ammonia after a major cleaning, so the problem was not noticed until the next day.

ImprovementOnly rinse media lightly in tank water, and replace it in portions over several weeks. Clean the filter on a different day from the water change. Test ammonia and nitrite daily for a week after cleaning, and respond to any rise with water changes and a feeding pause.

A week after you switched the substrate from fine sand to large pebbles, your 55 cm silver arowana sucked up sunken food together with gravel, could not spit it out, and struggled. It then seems to have swallowed it; its belly is bulging on one side and it has stopped eating. It has not passed feces for three days.

Which is the most appropriate first action?

1. Stop feeding, record the belly swelling and whether feces are passed, remove the pebbles, and consult a vet the same day
2. Mix oil into the food as a laxative
3. Press on the belly to push the stone out through the mouth
4. Give more sinking food to flush the stone through

AnswerA. Stop feeding, record the belly swelling and whether feces are passed, remove the pebbles, and consult a vet the same day

ExplanationLarge gravel swallowed with food lodges in the digestive tract and causes intestinal blockage or injury. Stop feeding, record the belly swelling and whether feces are passed, remove the pebbles that caused it, and consult a fish-capable vet the same day. An X-ray can sometimes locate the stone. Oil or human laxatives are harmful to fish and ineffective. Pressing on the belly injures the intestine. More food advances the blockage and leads to abdominal fluid or death. If food refusal and lack of feces continue, prompt veterinary care is required.

IssuesSwitching to large pebbles while continuing to feed sinking food created the conditions for ingestion. The owner did not know how forcefully an arowana sucks in food, or why a bare tank or thin substrate is recommended.

ImprovementUse a bare tank or a thin layer of fine sand, and keep gravel or small objects that fit in the mouth out of the tank. Feed at the surface and remove any food that sinks right away. Observe the belly shape and feces daily, and make two days without feces the trigger for a vet consultation.

2 a.m. in January, heavy snow causes a power outage. The heater and pump on the 180 cm tank have stopped, and the room temperature is expected to fall to 10°C. The tank holds a 70 cm silver arowana and the water is currently 27°C. Restoration time is "unknown until morning." You have foam board, blankets, and a battery-powered air pump at home.

Which is the most appropriate first action?

1. Boil water in a kettle and pour it directly into the tank
2. Move the fish to a bucket and place it in front of the space heater
3. Do nothing and sleep until morning while waiting for restoration
4. Add the battery-powered air pump, wrap the tank in foam board and blankets to retain heat, and stop feeding

AnswerD. Add the battery-powered air pump, wrap the tank in foam board and blankets to retain heat, and stop feeding

ExplanationThe greatest dangers in a power outage are hypoxia and falling water temperature. First secure oxygen with the battery-powered air pump, wrap the tank in foam board and blankets to limit heat loss, and stop feeding to prevent water fouling. A large tank holds a lot of water, so insulated it will not drop sharply for several hours. Pouring in boiling water causes local temperature shock and burns. Moving the fish to a bucket risks stress, hypoxia, and overheating by the space heater. Doing nothing could let the temperature fall to near 20°C by morning. After restoration, confirm the heater restarts and the temperature recovers gradually.

IssuesSupplies for a winter outage (insulation, battery-powered pump, hot-water bottles) had been prepared, but the procedure had not been memorized, so the initial response was hesitant. Knowledge that a large tank's water volume and mass work in favor of heat retention was lacking.

ImprovementPost a power-outage procedure sheet next to the tank and keep the foam board, blankets, battery-powered pump, and spare batteries together in one place. Get a high-capacity portable power station that can run the heater and pump for several hours. Run the procedure once a year as an outage drill.

3 p.m. in August, in a room without air conditioning, the 180 cm tank reads 33°C. Your 60 cm Asian arowana is breathing fast near the surface and not responding to food. Direct sunlight from the window is hitting the side of the tank. You do not own a cooling fan.

Which is the most appropriate first action?

1. Throw ice straight into the tank to bring the temperature down in one go
2. Move the fish to tap water in the cooler bathroom
3. Block the direct sunlight, increase aeration, and cool the room while changing water with water within 2°C of the tank
4. It will drop at night, so do nothing

AnswerC. Block the direct sunlight, increase aeration, and cool the room while changing water with water within 2°C of the tank

ExplanationAbove 32°C dissolved oxygen falls, and an arowana weakens rapidly from hypoxia and an overdriven metabolism. First block the direct sunlight with a blackout curtain, increase aeration, and while changing water with slightly cooler water within 2°C of the tank, blow a fan across the surface or cool the room. Throwing ice in causes local rapid chilling and temperature shock. Moving the fish to tap water is fatal from chlorine and the temperature difference. Waiting until night risks death from hypoxia. If breathing stays disturbed or the fish lies on its side, consult a vet the same day, and install a cooling fan or chiller urgently.

IssuesThe tank was placed where direct sunlight hits it, and no summer cooling equipment was prepared. Understanding that high water temperature causes hypoxia, and of the arowana's upper temperature limit, was lacking.

ImprovementPlace the tank out of direct sunlight and install a cooling fan or chiller before summer to keep the water at 30°C or below. Record the daytime maximum with a min-max thermometer and consider running the air conditioner continuously. Keep a spare air pump on hand.

At night, an earthquake of intensity 5-upper on the Japanese scale strikes. A large amount of water has spilled from the 180 cm tank and flooded the floor, and a thin crack is visible at a corner of the glass. The water level has dropped by a third, and your 70 cm silver arowana is thrashing wildly and hitting the walls. The pump is running, but the extension cord on the floor is sitting in water.

Which is the most appropriate first action?

1. Tape over the crack and refill the tank to the top
2. Cut the breaker or power, secure oxygen with a battery-powered pump, and prepare to move the fish to a spare container in case of aftershocks
3. Leave the tank alone until the fish calms down
4. Drain all the water and lay the fish on a towel on the floor

AnswerB. Cut the breaker or power, secure oxygen with a battery-powered pump, and prepare to move the fish to a spare container in case of aftershocks

ExplanationA cord sitting in water risks an electrical leak and electrocution, so first cut the breaker or power to make the area safe. Then supply oxygen with a battery-powered pump and, since a cracked tank may burst in an aftershock, prepare to evacuate the fish with its tank water into a large spare container or heavy bag. Taping the crack and refilling increases the water pressure and widens the crack. Leaving it means the risk of electrical leakage and tank collapse continues. Taking the fish out of the water is fatal. After evacuation, maintain temperature and oxygen and check the fish for injuries.

IssuesThe owner had not anticipated that tank water spills in an earthquake or that a power cord on the floor can leak current. No evacuation supplies such as a spare container or battery-powered pump had been prepared.

ImprovementSecure the tank with anti-seismic mats and keep the water level several centimeters lower to reduce spills. Mount power strips high off the floor and use a ground-fault interrupter. Keep a large container for temporary evacuation, a battery-powered pump, and insulation together in one place.

A typhoon-caused power outage is entering its third day. The 180 cm tank is wrapped in blankets and a battery-powered pump is supplying oxygen, but the filter is off. The water temperature has fallen to 24°C. Your 65 cm silver arowana is resting quietly on the bottom, and you feel "it hasn't eaten for three days, poor thing" and are about to feed it.

Which is the most appropriate judgment in this situation?

1. Keep feeding stopped while the filter is off and the water is cold; prioritize oxygen and warmth and wait for restoration
2. Give double the usual food to build its strength
3. Add live food and let the fish feed itself
4. Feed it, then do a full water change to reduce the waste

AnswerA. Keep feeding stopped while the filter is off and the water is cold; prioritize oxygen and warmth and wait for restoration

ExplanationFeeding while the filter is off causes undecomposed ammonia to spike and poison the fish. Moreover, at 24°C digestion is impaired and indigestion is likely. An adult arowana can tolerate one to two weeks without food, so the correct course during the outage is to keep feeding stopped and prioritize oxygen and warmth. Double rations or live food foul the water rapidly. A full water change causes temperature and water-quality shock and loses the remaining filter bacteria. After restoration, raise the temperature gradually, test the water, and then resume feeding in small amounts.

IssuesThe feeling that "it is sad not to feed it" overrode the knowledge that feeding during a filter outage fouls the water. No procedure or decision criteria had been set for a prolonged outage.

ImprovementState clearly in the outage procedure sheet: "Do not feed while the filter is off." Set up a large portable power station able to run the filter and heater. Decide in advance the thresholds for a temperature drop and the steps for resuming feeding after restoration (test the water, then start small).

A large typhoon is forecast to hit directly tomorrow. You keep a 70 cm silver arowana in a 180 cm tank, and a long power outage is expected. At home you have foam board, blankets, a battery-powered pump (with old batteries), and a portable power station (30% charged). You feed every day.

Which is the most appropriate preparation the day before?

1. Feed extra on the day so the fish does not go hungry during the typhoon
2. You can figure it out if the power goes out, so make no special preparation
3. Top the water up to the brim to increase the volume
4. Fully charge the power station, put in fresh batteries, stop feeding from the day before, and complete a water change

AnswerD. Fully charge the power station, put in fresh batteries, stop feeding from the day before, and complete a water change

ExplanationPreparation before a disaster determines survival. Fully charge the portable power station, replace the batteries in the battery-powered pump with new ones, stop feeding from the day before to reduce waste, and complete a water change to give the water quality a margin. Extra feeding leads to an ammonia rise during the outage. Without preparation the initial response is delayed. Filling the tank to the brim lets water spill in strong winds or shaking, and removes the air gap needed if the pump stops. Gather insulation and a flashlight next to the tank, and confirm the contact details of a fish-capable vet.

IssuesDespite the typhoon forecast, preparation lagged; the power station had not been charged and the batteries had not been checked. The basic thinking on feeding and water changes before a disaster was unknown.

ImprovementMake a pre-disaster checklist and complete charging, battery replacement, feeding stop, water change, and insulation placement the day before. Keep the power station fully charged at all times and replace batteries regularly. Inspect everything once a year before typhoon season.

Two weeks ago, you scraped algae in the tank bare-handed with a cut on your finger. Since then the cut has not healed; it is swollen reddish purple, and small lumps have appeared in a line from the finger toward the wrist. No fever, but the pain persists. Your 60 cm silver arowana is healthy and the tank is normal.

Which is the most appropriate action in this situation?

1. Apply an over-the-counter ointment and wait for it to heal on its own
2. The fish is not sick, so it is not an infection; leave it
3. See a dermatologist or physician and tell them your hand was in aquarium water
4. Lance the lumps with a needle to drain the pus

AnswerC. See a dermatologist or physician and tell them your hand was in aquarium water

ExplanationA hand wound exposed to aquarium water that will not heal, with lumps lining up toward the wrist, is typical of a skin infection by nontuberculous mycobacteria (fish tank granuloma). Ordinary ointment does not cure it, and the history of aquarium contact is key to diagnosis, so see a dermatologist or physician and tell them your hand was in aquarium water. The bacteria can be present in the tank even if the fish shows no symptoms. Lancing the lumps spreads the infection and makes it harder to treat. Treatment often requires long courses of antibiotics, so an early visit matters.

IssuesTank work was done bare-handed with a wound on the hand, without knowing that aquarium water can carry bacteria that infect people. The non-healing wound and lined-up lumps were left for two weeks, delaying the decision to see a doctor.

ImprovementWear rubber gloves for tank work whether or not you have a wound, and wash your hands with soap afterwards. Postpone work on days when you have a cut on your hand. For any wound or swelling that will not heal after contact with aquarium water, always see a doctor and report the exposure.

A family member was washing the filter media, tweezers, and feed bucket in the kitchen sink and washing the dishes with the same sponge. A few days later, two family members developed diarrhea and stomach pain. In the tank, your 55 cm Asian arowana is fed frozen shrimp and live food.

Which is the most appropriate hygiene measure?

1. Wash tank equipment in a dedicated place with dedicated tools, never in the kitchen; use separate dish sponges, and the family members should see a doctor
2. Sterilizing the dishes with boiling water makes the same sink fine
3. There is no option other than giving up fishkeeping
4. The family's diarrhea is unrelated, so do nothing

AnswerA. Wash tank equipment in a dedicated place with dedicated tools, never in the kitchen; use separate dish sponges, and the family members should see a doctor

ExplanationAquarium water and live or frozen food can carry bacteria such as Salmonella and Aeromonas, which can transfer to food and dishes via equipment washed in the kitchen or a shared sponge and cause food poisoning. Wash tank equipment in a dedicated place such as the bathroom or outdoors with a dedicated sponge and detergent, and never bring it into the kitchen. Keep dish sponges completely separate, and any family member with ongoing diarrhea should see a doctor. Boiling-water sterilization does not prevent contamination of the sponge and surroundings. Giving up fishkeeping is unnecessary; separating hygiene routes prevents this. Assuming it is unrelated is dangerous.

IssuesTank equipment and dishes were handled in the same sink with the same sponge, creating a route for bacterial infection of the family. The knowledge that aquarium water and food can carry human food-poisoning bacteria had not been shared within the family.

ImprovementDesignate a washing area for tank equipment outside the kitchen with a dedicated sponge, bucket, and detergent. Store live and frozen food in dedicated containers separate from human food. Make hand washing after tank work a habit for the whole family, and keep children and the elderly from handling equipment.

While hand-feeding your permitted 1 m alligator gar, it bit your finger along with the food. You pulled your hand back reflexively, and the fine teeth tore the skin on your finger, which is bleeding. Aquarium water got into the wound. The cut is deep and gapes about 1 cm.

Which is the most appropriate next action?

1. Rinse the wound with aquarium water and put on an adhesive bandage
2. Rinse the wound well under running water, stop the bleeding, see a doctor the same day, and tell them you were bitten by a fish
3. Open the gar's mouth to check whether any teeth are broken
4. Once the bleeding stops there is no problem, so do nothing

AnswerB. Rinse the wound well under running water, stop the bleeding, see a doctor the same day, and tell them you were bitten by a fish

ExplanationA laceration from a gar's sharp teeth contaminated with aquarium water is prone to infection by Aeromonas, mycobacteria, and others. Rinse the wound thoroughly under running water and stop the bleeding; a deep wound may need sutures or antibiotics, so see a doctor the same day and report that you were bitten by a fish and exposed to aquarium water. Rinsing with aquarium water only adds bacteria. Opening the gar's mouth risks another bite and stresses the fish severely. Left untreated, swelling, fever, or a non-healing wound often follows within days.

IssuesA large gar was hand-fed, and pulling the hand back reflexively when bitten widened the wound. The sharpness of a gar's teeth and the infection risk of a wound exposed to aquarium water were not understood.

ImprovementFeed with long tongs or a plastic rod and keep bare hands away from the surface. If bitten, do not pull away; wait in the water for the fish to let go. Keep a first-aid kit next to the tank, and make a deep wound the trigger for a same-day doctor visit.

A keeper with three large tanks netted a catfish showing white spots and gill problems, then used the same net and wet hands to feed the silver arowana in another tank and test its water. The following week, the arowana also begins showing white spots on its body and rubbing. The third tank is still symptom-free.

Which is the most appropriate response to this situation?

1. Combine the fish from all tanks into one and treat them all at once
2. The symptom-free tank is unaffected, so do nothing there
3. Add double the dose of fish medication to all tanks just in case
4. Use separate nets and tools for each tank and wash hands between them, manage the affected tanks in isolation, and consult a vet

AnswerD. Use separate nets and tools for each tank and wash hands between them, manage the affected tanks in isolation, and consult a vet

ExplanationWhite spot and gill parasites spread between tanks via nets, hands, and water droplets. Dedicate equipment to each tank, wash hands between tasks, and handle the affected tanks last. Manage the affected tanks in isolation and consult a fish-capable vet to choose medication. Combining the fish guarantees spread and worsens things through stress. The symptom-free tank may be in the incubation period, so keep observing it. Double-dosing medication damages an arowana's gills and kills filter bacteria. Keeping the temperature stable and changing water to maintain the fish's resistance is also important.

IssuesMultiple tanks were handled with the same net and hands, creating a hygiene route that spread parasites. The keeper did not understand that working order and tool separation are the basics of infection control with multiple tanks.

ImprovementColor-code and dedicate nets, tweezers, and buckets to each tank. Work from healthy tanks to sick tanks, washing hands and changing gloves in between. Quarantine new fish in a separate tank for two to four weeks.

In the morning, your 70 cm silver arowana is lying motionless on the bottom of the 180 cm tank. Its color is pale and its eyes do not seem to move. It was swimming normally last night. The overnight water temperature was 27°C and the pump is running. The owner assumes it is dead and is about to take it out.

Which is the most appropriate first action?

1. Take it out right away and put it in a plastic bag
2. Bang on the tank to see if it reacts
3. Check gill cover movement, the response to a light touch on the body, and eye movement, all in the water
4. Drop in food and judge by whether it eats

AnswerC. Check gill cover movement, the response to a light touch on the body, and eye movement, all in the water

ExplanationWhether a fish is alive and how serious its condition is are judged by gill cover movement (normally about 60–80 per minute), the escape response to a light touch, and eye movement. Even lying on its side, if the gills move slightly it is alive and there is room to save it. Check in the water; taking it out kills a fish that could have recovered. Banging on the tank adds shock from the impact. A response to food is not a useful indicator in a critically ill fish. If the gills are moving, turn aeration to maximum, keep it dark and quiet, test the water, and consult a vet the same day.

IssuesThe owner did not know how to determine whether a fish is alive (gill covers, response, eyes) and judged it dead by appearance alone, nearly removing it. There was also no habit of recording changes from the previous night to the morning.

ImprovementLearn the three-point check (gill cover movement, escape response, eye movement) and record the normal breathing rate. Decide the routine for abnormalities in advance: test water and temperature first, increase aeration, rest the fish in the dark, then consult a vet.

Late at night, you returned your 60 cm silver arowana to the tank with wet hands after it jumped out. But it sinks to the bottom lying on its side, and the gills move only very slightly. Water temperature 28°C, aeration already at maximum. The owner does not know what to do and is watching.

Which is the most appropriate next action?

1. Support it in the water facing forward and move it slowly back and forth so water passes over the gills, waiting for recovery
2. Take it out of the water, warm its body, and press on its heart
3. Blow gas from an oxygen canister directly into its mouth
4. Do nothing and wait until morning to see

AnswerA. Support it in the water facing forward and move it slowly back and forth so water passes over the gills, waiting for recovery

ExplanationCardiac massage and artificial respiration do not apply to fish; the life-saving measure is to pass oxygenated water over the gills. Support the fish in the water with its head facing forward, move it slowly back and forth so water flows through the gills, and continue until it begins moving its gills on its own. Turn the lights off and keep it quiet. Taking it out to warm it dries the gills and is fatal. Blowing oxygen gas into the mouth does nothing, since fish cannot breathe air, and damages the gills. Doing nothing leads to respiratory arrest. Once it recovers, check for injuries; if breathing stays weak, consult a vet even at night.

IssuesThe owner did not know the in-water resuscitation step after a jump (passing water over the gills) and could do nothing beyond aeration. The root cause was a poorly secured lid that allowed the jump.

ImprovementWrite the post-jump procedure (return with wet hands, aeration to maximum, pass water over the gills, rest in the dark) on a sheet posted next to the tank. Secure the whole lid and lower the water level to prevent recurrence. Confirm the contact details of a vet who can see fish at night.

1 a.m.: your 65 cm Asian arowana is lying on its side, with gill movement extremely weak at about 20 per minute. There are hemorrhagic spots on the body and the belly is swollen. The water tests nitrite zero at 28°C. Aeration has been at maximum for 30 minutes with no improvement. There is an after-hours vet that sees fish 40 minutes away by car.

Which is the most appropriate judgment in this situation?

1. Watch until morning, then call your regular vet
2. Call the after-hours vet, describe the situation, and following their instructions transport the fish in an oxygen-filled bag
3. Add a medication found online and wait for a response
4. Decide it cannot be saved and do nothing

AnswerB. Call the after-hours vet, describe the situation, and following their instructions transport the fish in an oxygen-filled bag

ExplanationLying on its side, markedly weak breathing, hemorrhagic spots, and a swollen belly suggest serious internal disease or septicemia; when water quality is normal and oxygen brings no improvement, it cannot be saved at home. Call the after-hours vet, describe the situation, and if they can take the fish, transport it in a heavy bag one-third full of water topped with oxygen, kept dark and warm. If they judge transport too risky, follow their instructions. Waiting until morning carries a high chance of death. Self-medicating from online information worsens the condition. This species requires a registration certificate, so bring it to the visit as well.

IssuesThe owner had no criteria for treating the combination of critical signs (on its side, weak breathing, hemorrhage, abdominal fluid) as an emergency, and had not checked transport supplies or after-hours vet details until the last moment.

ImprovementWrite "on its side," "extremely weak breathing," "bleeding," and "jaw will not close" into the procedure sheet as criteria for an after-hours emergency visit. Keep heavy bags, an oxygen canister, and a foam box on hand, and share the after-hours vet's contact details and the location of the registration certificate with the family.

Your 55 cm silver arowana crashed into the driftwood, tearing off about five scales on its flank, and blood is seeping into the water. It can swim but is restless. The owner is thinking of treating it like a human injury: taking the fish out and pressing gauze on it to stop the bleeding.

Which is the most appropriate way to stop the bleeding in this situation?

1. Take the fish out, press gauze on the wound, and wait until it dries
2. Apply a human styptic or antiseptic to the wound
3. Rub the skin under the lost scales to stop the blood
4. Keep it in the water, dim the lights, let it rest, and keep water quality at its best to prevent infection

AnswerD. Keep it in the water, dim the lights, let it rest, and keep water quality at its best to prevent infection

ExplanationBleeding in fish usually stops on its own if the fish rests in the water. Removing it from the water is itself life-threatening through gill drying, slime-coat damage, and severe stress, so stop bleeding in the water. Dim the lights to keep it from thrashing, and keep water quality at its best with temperature-matched changes to prevent wound infection. Pressing with gauze strips the slime coat and widens the wound. Human styptics and antiseptics do not work in water and can harm the fish. Rubbing the wound adds damage. If bleeding is prolonged, comes from the mouth or gills, or food refusal continues, see a vet the same day.

IssuesHuman first aid was applied directly to a fish, without understanding the danger of taking it out of the water. Leaving the sharp-cornered driftwood as a collision hazard in the tank was also a cause.

ImprovementShare the principle "treat fish in the water" with the family. Use a layout without sharp edges and create an environment that does not startle the fish. Photograph wounds to track progress, and make clouding, swelling, or food refusal the trigger for a vet visit.

You need to take your 70 cm silver arowana with a suspected jaw fracture to a vet an hour away by car. It is February and 5°C outside. You have heavy plastic bags, a foam box, an oxygen canister, and disposable hand warmers. The fish can swim but its mouth will not close.

Which is the most appropriate transport method?

1. Fill an uncovered bucket to the brim and put it on the passenger seat
2. Fill a bag to the brim with water, squeeze out the air, and tie it shut
3. Fill a heavy bag one-third with water and the rest with oxygen, double-bag it, and carry it in a foam box kept dark and warm
4. Wrap the fish in a wet towel and carry it in a box without water

AnswerC. Fill a heavy bag one-third with water and the rest with oxygen, double-bag it, and carry it in a foam box kept dark and warm

ExplanationThe standard way to transport a large fish is a heavy bag one-third full of tank water with the remainder filled with oxygen, double-bagged, in a foam box kept dark and warm. Using only one-third water secures enough oxygen and reduces the impact of the fish hitting the sides in transit. An uncovered bucket risks jumping and spills. A bag filled to the brim with the air squeezed out has no oxygen and the fish suffocates. Transport without water dries the gills and is fatal. In winter, place hand warmers outside the bag or in the gaps of the box so they never touch it directly, and keep 26–30°C.

IssuesThe owner did not know the method for transporting large fish (one-third water, oxygen, double bag, warmth, darkness) and was thinking in human terms of a bucket or wet towel. There was no awareness of preparing an emergency transport kit in advance.

ImprovementKeep a transport kit (heavy bags, rubber bands, oxygen canister, foam box, hand warmers, thermometer) next to the tank. Call the vet before transport with your expected arrival time and the fish's size. Keep the car warm and secure the bag so it cannot tip over.

Your 60 cm Asian arowana, kept for four years, has refused food for three days and its belly is swelling, so you booked a same-day appointment with a fish-capable vet. You are about to leave with only the fish in a bag. The registration certificate received at purchase is still in a drawer, and the water has not been tested recently.

Which is the most appropriate preparation for the visit?

1. Just bring the fish; the vet will check everything
2. Bring the registration certificate, readings for temperature, pH, and nitrite, tank size and water-change frequency, diet details, and photos and video of the symptoms
3. Add fish medication before the appointment to cure it before you go
4. Put fresh tap water in the bag instead of tank water

AnswerB. Bring the registration certificate, readings for temperature, pH, and nitrite, tank size and water-change frequency, diet details, and photos and video of the symptoms

ExplanationThe Asian arowana is a CITES Appendix I species; under the Act on Conservation of Endangered Species the registration certificate must be kept and carried, including for vet visits and transport. Diagnosis requires readings for temperature, pH, and nitrite, the tank size and water-change frequency, the diet, and photos and video showing the course of symptoms. With the fish alone it is hard to judge water-quality-related disease. Self-medicating before the appointment masks symptoms and distorts test results. Use tank water in the bag; tap water worsens the condition through chlorine and shock. Losing the certificate or having it in the wrong name creates legal problems, so decide on a storage place in advance.

IssuesThe owner did not understand the importance of the registration certificate and the obligation to carry it, and did not test the water routinely. There was no habit of recording the husbandry details needed for a visit, so the information needed for diagnosis was not assembled.

ImprovementKeep the registration certificate in a waterproof case, share its location with the family, and always carry it for vet visits and transport. Keep a husbandry log of water readings, water-change dates, diet, and condition, and take photos and video when something is wrong. Keep a vet-visit kit (records, bags, oxygen, insulation) together in one place.