HomeFish encyclopediaRay-finned fishesPipefishes and SeahorsesPipefishes and seahorsesJapanese seahorse Japanese seahorse (Hippocampus mohnikei) Scientific name: Hippocampus mohnikei Bleeker, 1853 The Japanese seahorse (Hippocampus mohnikei) is a marine fish of the family Syngnathidae. BiologyIn Zostera seagrass beds; also in estuaries. Length type refers to height (= TL - head length). 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 mohnikeiFamilySyngnathidae (Pipefishes and seahorses)OrderSyngnathiformes (Pipefishes and Seahorses)ClassActinopterygii (Ray-finned fishes)Maximum length8.0Common length5.0Depth range1 m (3 ft)EnvironmentMarine; demersal; non-migratory; depth range 1 - ? mClimateTropicalDistributionWestern Pacific: Japan and Viet Nam; occurrence along Chinese coast needs confirmation. Status: International trade is monitored through a licensing system (CITES II, since 5.15.04).Conservation status (IUCN)Data deficient (DD)Threat to humansHarmlessResilienceHigh, 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