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Fish

Lined seahorse

Hippocampus erectus
French name : Hippocampe moucheté (erectus)

The lined seahorse is a member of the family Syngnathidae, native to the western Atlantic from the eastern United States down through the Caribbean and Gulf of Mexico. It inhabits seagrass beds, mangroves, and estuaries. It has the characteristic upright posture, prehensile tail, and bony ringed body of seahorses, with color ranging from grey and brown to orange or yellow, often marked with fine lines and patterning that aids camouflage. It is peaceful and slow-moving, best kept in a dedicated species tank with gentle flow, hitching posts, and no aggressive or fast tankmates that would outcompete it for food. It requires frequent feeding of enriched frozen mysis and ideally accepts prepared foods over time. Males brood eggs in a belly pouch and give live birth, and captive-bred specimens are hardier. Suited to advanced keepers.

Water
Marine
Origin
Western Atlantic and Caribbean
Adult size
15 cm
Diet
Carnivore
Temperament
Peaceful
Difficulty
Advanced
Keep in group of
2+
Lined seahorse (Hippocampus erectus)
Illustration

Water parameters

Temperature20 – 25 °C
pH8.1 – 8.4
Carbonate hardness (KH)8 – 12 °dKH
Salinity33 – 35 SG

Tank & stocking

Minimum tank volume110 L
Volume budget per individual 40 L — adds up with tank-mates
Minimum group size2 individuals (shoaling)

“Minimum tank volume” is a reasonable floor, not an absolute limit. The per-individual budget is used by the Aqua app to estimate how heavily a tank is stocked.

Frequently asked questions

What size aquarium does Lined seahorse need?

Provide at least 110 litres for a small group to keep Lined seahorse in good conditions.

What water parameters does Lined seahorse need?

A temperature of 20–25 °C, pH 8.1–8.4, saltwater.

Is Lined seahorse peaceful or aggressive?

Its temperament is peaceful.

What does Lined seahorse eat?

Its diet: carnivore.

How many Lined seahorse should be kept together?

It is a social species: keep a group of at least 2.

How big does Lined seahorse get?

Around 15 cm as an adult.

Is Lined seahorse suitable for beginners?

Care level: advanced.

Planning a tank with Lined seahorse?

AquaTender turns these parameters into live advice: it checks whether your tank is big enough, how heavily it's stocked, and whether your fish are compatible — then tracks water tests, photos and maintenance for you.

➕ Add Lined seahorse to my tank Discover AquaTender
« Add to my tank » opens AquaTender — sign in (free) and pick your aquarium.

Fish from the same biotope

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