HomeFish encyclopediaRay-finned fishesPipefishes and SeahorsesPipefishes and seahorsesBig-head seahorse Big-head seahorse (Hippocampus grandiceps) Scientific name: Hippocampus grandiceps Kuiter, 2001 The Big-head seahorse (Hippocampus grandiceps) is a marine fish of the family Syngnathidae. BiologyDorsal spines (total): 0; Dorsal soft rays (total): 18. Pectoral fin rays usually 18; trunk rings 11; tail rings 32-33; head long, 94-103% of trunk length; head angled down to near trunk.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameHippocampus grandicepsFamilySyngnathidae (Pipefishes and seahorses)OrderSyngnathiformes (Pipefishes and Seahorses)ClassActinopterygii (Ray-finned fishes)Maximum length10.5Depth range10 m (33 ft)EnvironmentMarine; demersal; depth range 10 - 10 mClimateTropicalDistributionWestern Central Pacific: Gulf of Carpentaria, Australia. 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)Not EvaluatedThreat to humansHarmlessResilienceHigh, minimum population doubling time less than 15 months (Preliminary K or Fecundity.) SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026