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Pygmy Seahorse Hippocampus bargibanti Whitley, 1970
[CAAB 37 282106]

Distribution Map see an interactive map here (new window)

The Pygmy Seahorse is a tiny and highly specialised species that uses its prehensile tail to cling to gorgonian soft corals (seafans) of the genus Muricella. A master of camouflage, Hippocampus bargibanti exactly mimics in colour, body shape and tubercles, the seafan stalks and polyps.

Distribution, ecology and habitat:

Tropical West Pacific, including Indonesia, the Philippines, Japan, New Caledonia, Papua New Guinea, Solomon Islands and the Great Barrier Reef, Queensland, Australia; benthic on coral reefs at 16-60 m, specifically on gorgonian corals of the genus Muricella.

Size:

A tiny species, reaching a maximum height of about 24 mm; mimimum height at maturity 13 mm.

Food and feeding:

Presumably feeds on tiny crustaceans and may also feed on tissue of gorgonian corals, or on tiny zooplankton trapped in the polyps or slime.

Reproduction and early life history:

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. The breeding season extends from March to November and the Pygmy Seahorse seems to prefer the red polyp Muricella spp in depths over 20 m during breeding. Adult males and females are usually found in pairs or clusters of pairs (up to 28 on a single gorgonian) and may be monogamous.
Eggs: Not described; males brood the eggs in an enclosed pouch on the underside of the trunk. Brood size about 35 eggs.
Larvae: Pelagic. Larvae born after a gestation period of 2 weeks and are about 2 mm long at birth; larvae morphologically similar to adults; post-pelagic young have the enlarged tubercles and distinctive colour pattern of the adults and settle on various gorgonian hosts.

Characteristics:

Meristics: D 13-15; A absent in adults; P 10; trunk rings 11-12; tail rings 31-34; subdorsal rings obscured.
Head and body: Head and body extremely fleshy without recognisable bony rings; spines or tubercles not visible, becoming overgrown with soft tissue, forming large bulbous or wart-like lumps in adults; snout extremely short, tip bulbous; head angled at 90° to the trunk.
Spines and tubercles: A single prominent rounded fleshy bulbous spine is present above each eye and on each cheek; spines otherwise absent. Body ornamentation is in the form of irregular prominent bulbous tubercles on the body and tail.
Coronet: Coronet rounded, knob-like, spines absent.
Fins: Dorsal fin very short-based, wholly on trunk; anal fin absent in adults.
Lateral line: Obscured.

Colour:

Colour is variable depending on the host gorgonian species. Individuals living on the gorgonian, Muricella plectana, are pale striated grey or purple with pink or red tubercles to match the gorgonian. Individuals living on M. paraplectana are yellow with orange/yellow tubercles. The tail is striped with dorsolateral circular markings.

Similar species:

H. bargibanti most closely resembles H. denise Lourie & Randall 2003, and H. satomiae Lourie & Kuiter 2008, both of which are not found in Australian waters. Although somewhat similar, the very rare H. minotaur, found in relatively deep waters off southeastern Australia, has no obvious tubercles on the body.

Fisheries:

There is no known trade in this species for the aquarium industry. The Pygmy Seahorse would be difficult to in home aquaria as they are reliant on their gorgonian hosts.

Conservation Status:

International: Listed under Appendix II of the Convention on the International Trade in Endangered Species of Wild Flora and Fauna  (CITES).

Listed as Data Deficient on the 2008 IUCN Red List of Threatened species (International Union for Conservation of Nature).

Australian Government Legislation: Marine Listed under the Federal Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act 1999)

Remarks:

Part of the gorgonian coral appears to live symbiotically in the skin of the Pygmy Seahorse and reacts into wart-like growths around the short spines on the head and body. The resulting camoflauge is so effective that the species was only discovered after a pair of individuals was found attached to a gorgonian seafan collected by Georges Bargibant for the Nouméa Aquarium in New Caledonia.

Other common names:

Gorgonian Seahorse, Bargibant's Seahorse.

Original citation:

Hippocampus bargibanti Whitley 1970, Proc. Linn. Soc. N. S. W. 94(3): 294, New Caledonia.

Etymology:

From the Greek, ippos = horse and kampe = curvature. The species is named for Georges Bargibant who collected the gorgonian sea fan on which H. bargibanti was discovered.

References:

Allen, G.R. & M. Adrim. 2003. Coral reef fishes of Indonesia. Zool. Stud. 42(1):1-72.

Gomon, M.F. 1997. A remarkable new pygmy seahorse (Syngnathidae: Hippocampus) from south-eastern Australia, with a redescription of H. bargibanti Whitley from New Caledonia. Mem. Mus. Vict. 56(1): 245-253.

Foster, S.J. & A.C.J. Vincent. 2004. Life history and ecology of seahorses: implications for conservation and management. J. Fish Biol. 65: 1-61.  

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.

Kuiter, R.H. & T. Tonozuka. 2001. Pictorial guide to Indonesian reef fishes. Part 1. Eels- Snappers, Muraenidae - Lutjanidae. Zoonetics, Australia. 302 pp.

Laboute, P. & R. Grandperrin. 2000. Poissons de Nouvelle-Calédonie. 2^nd Ed. Catherine Ledru: 520 pp.

Lourie, S.A.  & R.H. Kuiter. 2008. Three new pygmy seahorse species from Indonesia (Teleostei: Syngnathidae: Hippocampus). Zootaxa 1963: 54-68.

Lourie, S.A.  & J.E. Randall. 2003. A new pygmy seahorse, Hippocampus denise (Teleostei: Syngnathidae), from the Indo-Pacific. Zoological Studies 42(2): 284-291.

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.

Michael, S.W. 2001. Reef Fishes Volume 1: A guide to their identification, behaviour and captive care. TFH Publications Inc. New Jersey, USA.

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.

Randall J.E., G.R. Allen & R. Steene. 1997. Fishes of the Great Barrier Reef and Coral Sea. Crawford House Press, Bathurst. 2^nd Ed. 557 pp.

Tackett, D. & L. Tackett. 1997. Pygmy seahorse: the lilliputian reef rider. Asian Diver October/November 1997: 61-63.

Whitley, G.P. 1970. Bargibant's sea-horse from New Caledonia. In Abstracts of Proceedings. Proc. Linn. Soc. N. S. W. 94(3)421: 292-295.