HomeFish encyclopediaRay-finned fishesPipefishes and SeahorsesPipefishes and seahorsesLongnose seahorse Longnose seahorse (Hippocampus trimaculatus) Scientific name: Hippocampus trimaculatus Leach, 1814 The Longnose seahorse (Hippocampus trimaculatus) is a marine fish of the family Syngnathidae. BiologyInhabits gravel or sand bottoms around shallow reefs; muddy estuaries and near mangroves, tolerating brackish waters. Ovoviviparous. The male carries the eggs in a brood pouch which is found under the tail.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameHippocampus trimaculatusFamilySyngnathidae (Pipefishes and seahorses)OrderSyngnathiformes (Pipefishes and Seahorses)ClassActinopterygii (Ray-finned fishes)Maximum length22.0Depth range100 m (328 ft)EnvironmentMarine; reef-associated; non-migratory; depth range ? - 100 m, usually ? - 20 mClimateTropicalDistributionIndo-Pacific: southern India to Japan, Australia and Tahiti. International trade is monitored through a licensing system (CITES II, since 5.15.04) and a minimum size of 10 cm applies.Conservation status (IUCN)Vulnerable (VU) (A4cd)Threat to humansHarmlessUsesAquaculture: commercialResilienceHigh, minimum population doubling time less than 15 months (tm=0.5-1) SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026