Lined Seahorse (Hippocampus erectus) Care Guide
A medium-sized seahorse reaching 15cm, one of the more commonly captive-bred species available. Needs a species-only tank with gentle flow, hitching posts (gorgonians, macroalgae), and frozen mysis sh…
Compiled by Aquairi from published sources · Published · Updated
Overview
Hippocampus erectus is a species in the family Syngnathidae. A medium-sized seahorse reaching 15cm, one of the more commonly captive-bred species available. Needs a species-only tank with gentle flow, hitching posts (gorgonians, macroalgae), and frozen mysis shrimp. Males carry young in a brood pouch. Slow feeder easily outcompeted.
Taxonomy
- Family: Syngnathidae
- Genus: Hippocampus
- Scientific name: Hippocampus erectus
- Other names: Northern Seahorse
- Origin: Western Atlantic
Habitat
Distributed along the western Atlantic from Nova Scotia south to Venezuela, including the Gulf of Mexico and the Caribbean. Inhabits seagrass beds, mangrove roots and floating sargassum mats. Listed as Vulnerable on the IUCN Red List; one of the most commonly captive-bred seahorse species for the trade.
Tank requirements
- Minimum tank volume: 100 L
- Temperature: 22-25 °C
- pH: 8.1-8.4
- GH: 8-12 °dGH
- Water flow: low
- Adult size: 10-15 cm
- Lifespan: 3-5 years
- Recommended group size: ≥ 2
- Difficulty: intermediate
Diet
Classified as carnivore. Recommended feeding frequency: 2x daily. In captivity, offer a varied diet appropriate to the species — quality prepared foods supplemented with frozen or live items of suitable size.
Compatibility
- Temperament: peaceful
- Swimming level: middle
- Compatible tank mates: Other Seahorses, Pipefish, Snails
- Avoid with: All Active Fish, Crabs, Anemones, Strong Flow
Reef compatibility
Generally classified as reef-safe with caution: may opportunistically pick at small ornamental shrimps, sessile invertebrates or, in some individuals, polyps. Suitability depends on the specific reef stock.
Breeding
- Breeding strategy: pouch-brooder (male carries eggs)
- Breeding difficulty: intermediate
Lined Seahorse (Hippocampus erectus) Breeding Guide
Overview
Hippocampus erectus reaches about 17.8 cm and ranges through the Western Atlantic from Canada to Brazil, including the Gulf of Mexico and West Indies, where it associates with gorgonians, seagrasses and floating Sargassum (FishBase). It is one of the more commonly captive-bred seahorses. The species is ovoviviparous, with eggs developing in a brood pouch beneath the male's tail (FishBase). IUCN status is Vulnerable, and the species is listed on CITES Appendix II (FishBase, Wikipedia).
Sexing
Males are identified by the brood pouch under the tail and develop it at about 5-7 months of age; females lack the pouch (Wikipedia). Fish reach full size by roughly 8-10 months (Wikipedia).
Conditioning
The lined seahorse is a slow feeder easily outcompeted by faster tankmates, so it is conditioned in a calm species-only tank with gentle flow and frequent feeding of suitable frozen and live foods. Stable parameters in the reported range support reproduction.
Breeding Setup
A species-only aquarium with low flow and abundant hitching structure such as gorgonians or macroalgae suits a pair or small group. Pairs bond and the male's pouch maintains oxygen via a capillary system and regulates internal sodium and calcium levels during pregnancy (Wikipedia).
Spawning Behavior & Trigger
Pairs are reported to be monogamous, choosing partners they continue to mate with, and perform daily ritual dances and produce clicking sounds by moving the coronet against the skull to maintain their bond (Wikipedia). During transfer the female deposits her eggs into the male's pouch, where they are fertilized and incubated.
Egg & Fry Care
Females can produce 97 to 1,552 eggs, and a single male can carry up to about 650 at once; FishBase cites fecundity of roughly 1,552 young per event (Wikipedia, FishBase). Gestation lasts 20-21 days, varying with temperature, after which the male anchors his tail and arches rhythmically to release the young (Wikipedia, FishBase). Newborns are about 11 mm and tend to swim near the surface after birth; survival is low, reported at only about two juveniles per hundreds hatched (Wikipedia). The partly pelagic, surface-associated fry are more difficult to rear than the benthic young of the dwarf seahorse.
Common Challenges
The large brood, low natural survival, and surface-swimming fry make rearing demanding: gentle flow, a steady supply of small live foods, and careful nursery management are needed. Slow adult feeding also requires that seahorses not be housed with fast competitors.