Northern Spiny Seahorse, Hippocampus multispinus Kuiter 2001

A Northern Spiny Seahorse, Hippocampus multispinus. Source: Rudie Kuiter / Aquatic Photographics. License: All rights reserved


This very spiny species is found only in northern Australia and southern Papua New Guinea.

Cite this page as:
Hippocampus multispinus in Fishes of Australia, accessed 19 May 2024,

Northern Spiny Seahorse, Hippocampus multispinus Kuiter 2001

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Tropical Southwest Pacific, in northern Australia and Papua New Guinea; in Australia found from northwestern Australia to the Gulf of Carpentaria; benthic on soft bottom habitats between 10 and 60 m, mostly trawled at 20-60 m.


Meristics: D 18; P 16-18 (usually 17); trunk rings 11; tail rings 30-35; subdorsal rings 2 + 1.
Head and body: Head moderately long, about ¾ trunk length; snout long, just over half head length; double spines below eye; nape spine directed forward, placed away from coronet; shoulder-ring with 3 long spines, 2 lowermost in form of laterally directed, diverging spines; lateral ridge with long spines but spines absent from rings 1, 3, 5 and 11.
Spines and tubercles: Spines long and sharp, spine above eye perpendicular to snout, equal in length or longer than eye-diameter; nasal-spine sharp, angled forward 45° to snout, anterior spines on superior tail ridge longer than spaces between them; subdorsal spines 3/0,1,0.
Coronet: Coronet with 5 long divergent spines.
Lateral line: Lateral line indistinct, comprising small pores each with a single papilla, intermittently detectable on tail to 20th ring.


Height to 140 mm.


Overall dark brown from rear of head to end of tail; head white with few brown spots radiating from eye; whitish bands on trunk rings 1, 4, 6, 8 and 11; spines mostly white around bases, the tips black. May also be orange-gold with few small white spots scattered over the head and faint dark bars on the snout. In preservative - pale brown without markings, sometimes with few faint dusky bars on snout.


Unknown. Like other seahorses, this species presumably feeds by sucking small crustaceans and other small prey items, including planktonic zooplankton, into their mouths.


Reproduction: Sexes separate, reproduction a form of viviparity or ovoviviparity, whereby the 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.


No known international trade for 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,
Australian legislation: Marine Listed under the Federal Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act 1999).


Males are much less spiny than females

Similar Species

H. multispinus has been confused with H. histrix, H. spinosissimus, and H. hendriki, other species with prominent spines. H. multispinus has long double, divergent spines rather than the single long lower shoulder-ring spine in H. histrix. The snout of H. spinosissimus is less than half the head length whereas in H. multispinus, the snout is longer than half the head length. H. hendriki is similar in morphology but with shorter spines and saddle-like markings.


From the Greek ippos = horse and kampe = curvature. The specific name multispinus is from the Latin multus meaning numerous and spinus meaning thorny or spiny, in reference to the numerous spines over the head and body.

Species Citation

Hippocampus multispinus Kuiter 2001, Rec. Aust. Mus. 53: 331, fig. 45, Arafura Sea, Northern Territory, Australia.

Northern Spiny Seahorse, Hippocampus multispinus Kuiter 2001


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, 2178 pp.

Kuiter, R.H. 2000. Seahorses, Pipefishes and their Relatives. TMC Publishing, Chorleywood, UK, 240 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.

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.

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