Seahorse

Gas bubble disease

SignsBubble-like swellings on the tail or body; in males the brood pouch inflates and the fish floats and cannot sink; tail tip swells white

PreventionAvoid air stones that produce fine bubbles and prevent gas supersaturation. Keep temperature and water quality stable, and avoid tail injuries

Snout injury / snout rot

SignsSnout tip turns cloudy white, red and swollen, or chipped. Cannot suck in food; mouths at it but loses weight

PreventionNever scoop with a net; move in a container. Reduce sharp edges on rocks and hard decor, and fit sponges on pump intakes

Feeding difficulty / wasting

SignsSunken belly with bony plates showing, no response to food, spits out frozen food, sluggish

PreventionFeed frozen mysis 2–3 times a day and remove leftovers. Gather food in a feeding dish and confirm it is eaten every time

Vibriosis

SignsRed ulcers or hemorrhagic spots on the body, fins dissolve, sudden refusal of food; can die suddenly within days

PreventionTriggered by rising temperature and poor water quality. Keep nitrite at zero and nitrate low; isolate weakened animals early

Marine ich / Oodinium (velvet)

SignsWhite spots or a gold-dust coating on the body, rapid breathing, rubbing against rocks, rapid gill movement

PreventionQuarantine new fish and live feeder animals before introduction. Avoid sudden temperature changes; consult a vet or shop about quarantine treatment

Bacterial dermatitis / tail rot

SignsTail tip turns cloudy white and breaks down, weaker grip, skin peels with cotton-like material attached

PreventionUse smooth materials where the tail grips. Do regular water changes, and isolate and watch any injured animal

Sucked into an intake

PreventionCover every pump and filter intake with a sponge. Reduce flow and position so current does not hit the fish directly

First aidTurn off the pump and release gently. Check the tail and skin for injury and rest in a quarantine tank. See a vet the same day if there is bleeding or ulceration

Tail injury / tear

PreventionNever scoop with a net. Avoid sharp coral skeletons and rough artificial rock; use smooth branches or artificial seaweed as holdfasts

First aidMove to a quarantine tank and keep the water clean. Add thin branches that are easy to grip; see a vet if the tail tip turns cloudy or breaks down

Stings from other fish or invertebrates

PreventionDo not house with anemones, strongly stinging corals, hermit crabs or crabs. Do not add food competitors either

First aidSeparate the offending animal. Check for red swelling or ulcers and watch at every feeding whether it eats. See a vet the same day if it does not eat

Tangled in nets or equipment

PreventionAlways move with a handled container or cup, water and all. Eliminate gaps in nets, heater guards and feeders

First aidDo not pull; move the equipment itself underwater to free it. Never straighten and pull the tail. If fins or skin are injured, isolate and observe

Nontuberculous mycobacteriosis

RouteThrough cuts on the hands touching tank water or the fish

PreventionWear waterproof gloves if you have cuts. Wash hands with soap after tank work; see a dermatologist for a lump that won't heal

Vibrio infection

RouteThrough hand wounds when handling seawater or raw shrimp

PreventionPeople with liver disease or weakened immunity should use gloves. See a doctor right away for red swelling of a wound or fever

Erysipeloid

RouteThrough hand wounds when handling live feeder shrimp or the fish

PreventionThaw frozen food in a dedicated container. Wash hands after work; see a doctor if a finger turns red and swollen

Streptococcal infection

RouteBody fluids of sick fish or tank water contacting hand wounds

PreventionWear gloves when treating sick fish. Never start a siphon by mouth; use a hand pump

Food

• Frozen mysis (enriched) 2–3 times a day. Split the daily amount for its body size into several feedings
• For juveniles or when refusing food, enrich live mysis or adult brine shrimp
• Let food drift in front of it using a feeding dish or weak current, and confirm it eats every time

Water

• Maintain artificial seawater at specific gravity 1.021–1.025 with zero ammonia and nitrite
• Keep nitrate low; change 20–30% weekly with water of the same temperature and gravity

Toys & play

• Several places to wrap the tail, such as artificial seaweed or branch-like artificial rock
• Slow-moving live mysis or brine shrimp bring out hunting behavior
• For a pair, provide enough height (water depth) for the courtship dance

Nest, bed & hideout

• Create hiding places like a seaweed thicket and calming shaded spots
• Provide holdfasts both near the surface and near the bottom

Bedding & litter

• A thin layer of fine sand, or no substrate, to make cleaning leftover food easy
• Avoid coarse gravel or sharp coral sand that injures the tail
• Remove leftover mysis with a pipette every time to prevent decay

Cage / housing material

Glass or acrylic marine tank. A tall, column-style type

Size & space

60 L or more for a pair, at least 45 cm tall. A 90 cm tank for pot-bellied

Layout

• Cover every intake with a sponge and keep the flow weak and diffused
• Place holdfasts in the upper, middle and lower levels
• Set a feeding spot where a weak current lets food collect

Placement notes

• Avoid direct sunlight and hot locations; keep a thermometer in the tank at all times
• Use a lid to prevent jumping out and salt creep, and place on a stand that won't tip in an earthquake

Exercise, free-roam & walks

• Exercise is within the tank only. Weak swimmers, so keep current gentle with many resting spots
• Chasing food counts as exercise, so split feedings into several sessions
• When moving or cleaning, do not touch by hand; transfer in a container with water

Temperature & humidity

TemperatureSpotted seahorse 24–26°C. Pot-bellied 16–20°C (chiller required)

HumidityNo humidity control needed for the tank. A lid limits evaporation and salt creep

Summer & winter

• In summer use a cooling fan or chiller to prevent high temperatures and vibriosis
• In winter fit a heater guard; in a power outage keep the temperature up with insulation

Nail trimming

No nail trimming. Instead check the tail tip daily for cloudiness or injury and use smooth materials where it grips

Brushing, skin & coat care

No coat care. At feeding time shine a light on the body to check for cotton-like material, white spots or red patches

Other care

Check the snout shape and suction strength at every feeding. Wash feeding tools every time and use up thawed food

Protection from predators

• Always use a lid so cats cannot reach into the tank
• Do not house with anemones, crabs or aggressive fish
• Keep a battery-powered air pump so a pump stoppage in an outage does not cause oxygen loss

Foreign-body ingestion

The snout is thin, so large food or sand grains sucked in can block it. Use fine substrate and food sized for the snout. See a vet if it cannot spit it out

Being stepped on

Not trodden on, but grabbing a jumped-out fish with bare hands damages the bony plates and skin. Scoop with a wet container, water and all, and return to the tank immediately

Getting pinched

The tail gets caught in gaps in heater guards and feeders. Choose equipment without gaps; do not pull, move the equipment itself to free it

Falls

A tank tipping over or leaking is the biggest fall accident. Use an earthquake-resistant stand and tank mat, and keep a battery-powered air pump for outages

Escape

Jumping out through lid gaps is rare, but being sucked into an intake is common. Cover every intake with a sponge and count the animals daily

Safe release procedure

1. If the tail wraps around your finger, keep your hand underwater and don't move
2. Offer seaweed or a branch near the tail and wait for it to switch over
3. If it still won't let go, gently stroke from the base of the tail to unwind it
4. If tangled in a net, submerge the net and wait for it to swim out

After the release

Check the animal's tail tip and skin for injury. If you have a cut, rinse under running water and see a doctor if it swells

What to tell the vet & what to bring

Temperature, specific gravity, ammonia, nitrite and nitrate readings, diet, tank mates, photos and video

Checking consciousness, breathing & heartbeat

• Normal: gill covers move slowly and regularly, and it holds on with its tail
• Weakening: breathing becomes fast and shallow, it lets go and drifts sideways
• Even if it lies down and the gills nearly stop, keep treating for a few minutes

Stopping bleeding

• Do not touch surface bleeding; move to a quarantine tank with clean seawater
• Remove the decor or animal that caused the bleeding
• See a vet the same day if bleeding continues or ulcers spread

Transport

• Put tank water in a bag or container with plenty of air, keep dark and insulated
• Add one branch to hold onto and minimize shaking and temperature change