Smooth Seahorse, Hippocampus kampylotrachelos Bleeker 1854

A Smooth Seahorse, Hippocampus kampylotrachelos. Source: Rudie Kuiter / Aquatic Photographics. License: All rights reserved


A relatively smooth  dusky brown to greyish seahorse with fine black and white spots and scribbles, and a poorly developed crown and coronet. The only Australian record of the Smooth Seahorse is a dried specimen found amongst nesting seabirds at Ashmore Reef off north Western Australia.

Cite this page as:
Vanessa J. Thompson & Dianne J. Bray, Hippocampus kampylotrachelos in Fishes of Australia, accessed 28 May 2024,

Smooth Seahorse, Hippocampus kampylotrachelos Bleeker 1854

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A Ogawa


Tropical Western Pacific from Sumatra, Bali and Ashmore Reef; benthic on muddy substrates in very sheltered estuaries, or in deep coastal waters, in 3-10 m.


Meristic features: Dorsal fin 19; Anal fin 4; Pectoral fin 16; trunk rings 11; tail rings 39; subdorsal rings 2 + 1.
Dorsal profile of head evenly concave to tip of snout; snout about half head length.
Head angled at more than 45°, nasal profile without spine, gradually curving onto snout with no obvious inflection; upward directed nape-spine; subdorsal 3/0,1,0, lower spine enlarged and obvious; body tubercles small to moderate along dorsal and lateral ridges, but enlarged and pointed at regular intervals, especially at dorsal-fin base and along superior tail ridges, gradually becoming smaller on tail.
Coronet low, directed backwards, with 5 blunt diverging spines in a star at apex.


Height to at least 22 cm


Overall dusky brownish grey to almost black, covered with fine white and black spots and scribbles, especially on head where these form a pattern radiating from eyes and lines along lower part of operculum; dorsal fin with two longitudinal lines, one marginally and one centrally.


Like other seahorses, this species presumably feeds by sucking small crustaceans and other planktonic organisms into its mouth.


Males give birth to tiny independent young. The female uses an ovipositor to transfer her eggs into an elaborate enclosed pouch under the abdomen of the male. The male not only fertilizes the eggs inside the pouch and provides physical protection for the developing embryos, he also osmoregulates and aerates the embryos and may provide some nourishment until the offfspring are born.
Eggs: Not described.
Larvae: Not described.


None. There is no known trade in this species in the aquarium or Asian Traditional Medicine industries.


International: Listed under Appendix II of the Convention on the International Trade in Endangered Species of Wild Flora and Fauna (CITES). As a result, the species is subject to the Convention,
Listed (as a synonym of H. trimaculatus) as Data Deficient on the 2007 IUCN Red List of Threatened species.
Australian Government Legislation: Marine Listed under the Federal Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act 1999).


H. kampylotrachelos is known from very few specimens and is regarded as a synonym of H. trimaculatus by some authors.

Similar Species



Hippocampus is from the Greek ippos = horse and kampe = curvature. The specific name kampylotrachelos is from the Greek kampe meaning caterpillar and trachelos meaning neck.

Species Citation

Hippocampus kampylotrachelos Bleeker 1854, Nat. Tijdschr. Ned. Ind. 7: 107, Priaman, Sumatra, Indonesia.


Vanessa J. Thompson & Dianne J. Bray

Smooth Seahorse, Hippocampus kampylotrachelos Bleeker 1854


Bleeker, P. 1854. Overzigt der ichthyologische fauna van Sumatra, met beschrijving van eenige nieuwe soorten. Natuurkd. Tijdschr. Neder. Indië 7: 49-108.

Hoese, D.F., D.J. Bray, J.R. Paxton & G.R. Allen. 2006. Fishes. In Beesley, P.L. & A. Wells. (eds.) Zoological catalogue of Australia. Volume 35. ABRS & CSIRO Publishing: Australia Part 1, 2178 pp.

Kuiter, R.H. 2001. Revision of the Australian Seahorse of the genus Hippocampus (Syngnathiformes: Syngnathidae) with descriptions of nine new species. Rec. Aust. Mus. 53: 293-340.

Kuiter, R.H. 2009. Seahorses and their relatives. Aquatic Photographics, Seaford, Australia, 333 p.

Lourie, S.A., A.C.J. Vincent & H.J. Hall. 1999. Seahorses: an identification guide to the world's species and their conservation. Project Seahorse. London, UK. 214 pp.

Pogonoski, J.J., D.A. Pollard & J.R. Paxton. 2002. Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes, Canberra, Environment Australia, 375 pp.

Quick Facts

CAAB Code:37282113

Biology:Male brood pouch

Depth:0-50 m

Habitat:Coral reef

Max Size:22 cm (height)

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