White's Seahorse, Hippocampus whitei Bleeker 1855

Other Names: New Holland Seahorse, Sydney Seahorse, Whites Seahorse

White's Seahorse, Hippocampus whitei. Source: Dave Harasti / http://www.daveharasti.com/. License: All rights reserved


Although locally abundant in Port Stephens and Sydney Harbour, White's Seahorse is found only from Wallis Lake to Lake Illawarra in New South Wales. It occurs in shallow weedy areas in estuaries, bays and harbours, usually attached to seagrass, sponges and kelp holdfasts - and the netting of public harbour pools.

Video of a White's Seahorse dad giving birth to his offspring in Nelson Bay, Port Stephens, New South Wales.

Cite this page as:
Bray, D.J. & Thompson, V.J. 2018, Hippocampus whitei in Fishes of Australia, accessed 07 Jun 2020,

White's Seahorse, Hippocampus whitei Bleeker 1855

More Info


Endemic to eastern Australia, from north of Mackay, Queensland, to WollongongNew South Wales. Records from elsewhere (Gulf of Carpentaria, Victoria, South Ausralia, New Guinea, western Indian Ocean and Vanuatu) are based on misidentifications.

White's Seahorse inhabits shallow inshore areas in estuaries, harbours and bays, where it lives on rocky reefs, sponges, seagrass beds, and under piers and jetties to 25 m.


Dorsal fin 16-17 (usually 17); Anal fin 4; Pectoral fin 13; Trunk rings 11; Tail rings 33-34; Subdorsal rings 2 + 1.

Head length about 90% of trunk length; snout length almost half head length; trunk length about one-third height; tail length about two-thirds height.

Spine above eye of moderate size; nape spine small; shoulder-ring spines of moderate size in 3 locations, one near each end of pectoral-fin base but none at gill-opening, lowermost spine double with sub-equal spines; lateral head spine low; body tubercles of small to moderate size along dorsal and lateral ridges, some enlarged and pointed, especially on eighth trunk ring, below dorsal fin and on following part of superior tail ridges; neck-ridge spines absent.

Coronet moderate to tall in height, angled back, spines small and blunt in young, further reduced in large adults, arranged in five-point star at apex, with additional 2 or more small spines anteriorly on base.


Height to about 150 mm, commonly to 200 mm TL.


In life, overall pale to dark brown and almost black, with fine pale spots or striations; sometimes entirely yellow; often saddle-like markings at the first, fourth and eighth trunk rings, and on tail rings where spines are enlarged; snout finely barred with dusky lines dorsally, lines broader near eyes; nasal spine and adjacent area pale.


Carnivores - feed on small crustaceans and passing zooplankton.


The sexes are separate, and females are egg-layers. The female uses an ovipositor to transfer her eggs into an elaborate enclosed pouch under the abdomen of the male. He male not only fertilizes the eggs inside the pouch and provides physical protection for the developing embryos, but also osmoregulates and aerates the embryos and may provide some nourishment until the offfspring are born.

Each male may brood 100-250 embryos. Following a gestation period of about 3 weeks, up to 150 independent young are born, usually at night. Larger females produce more eggs. Egg diameter 1.8 mm. Males rear several broods each season and often mate again within several days of giving birth.

There is no pelagic larval phase, and the young are morphologically similar to the adults at birth. Newborns are about 8.5 mm long.

Males may have up to seven broods during the breeding season and may mate again the following day after giving birth.


White's Seahorse is collected (under permit) for the aquarium industry and captive-bred individuals are sold mostly in Australia.


  • NSW Fisheries Management Act 1994 : Protected
  • EPBC Act 1999 : Marine Listed
  • IUCN Red List : Data Deficient
  • CITES : Listed under Appendix II 



Males and females form monogamous pairs the breeding season from spring to autumn. Individuals live in small overlapping home ranges. Each morning while the male is ‘pregnant', partners greet each other and the female performs a greeting ritual. Courtship behaviour may last up to 9 hours.

Similar Species

H. whitei has been misidentified as  H. tristis, H. procerus and H. breviceps.

H. whitei is most similar to H. procerus, having fewer fins rays, a lower coronet and in generally being less spiny.

H. tristis and H. breviceps both differ from H. whitei in having the upper shoulder-ring spine near the gill-opening rather than the pectoral-fin base.


From the Greek ippos = horse and kampe = curvature. The specific name whitei is after John White, surgeon-general of the First Fleet and author of Journal of a Voyage to New South Wales 1789, in which a portrait of H. whitei is published.

Species Citation

Hippocampus whitei Bleeker 1855, Verh. Akad. Amsterdam 2: 17. Type locality: Sydney district, NSW.


Bray, D.J. & Thompson, V.J. 2018


Australian Faunal Directory

White's Seahorse, Hippocampus whitei Bleeker 1855


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Clynick, B.G. 2008. Harbour swimming nets: a novel habitat for seahorses. Aquatic Conservation: Marine and Freshwater Ecosystems 18: 483–492.

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. Memoirs of Museum Victoria 56(1): 245-253.

Gomon, M.F., Glover, C.J.M. & Kuiter, R.H (eds) 1994. The Fishes of Australia's South Coast. Adelaide : State Printer 992 pp. 810 figs.

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Harasti, D., Glasby, T.M. & Martin-Smith, K.M. 2010. Striking a balance between retaining populations of protected seahorses and maintaining swimming nets. Aquatic Conservation: Marine and Freshwater Ecosystems 20: 159–166.

Hellyer, C.B., Harasti, D. & Poore, A.G. B. 2011. Manipulating artificial habitats to benefit seahorses in Sydney Harbour. Aquatic Conservation: Marine and Freshwater Ecosystems 21: 582–589.

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Quick Facts

CAAB Code:37282027

Biology:Males brood the eggs

Conservation:IUCN Data Deficient

Depth:1-25 m

Habitat:Rocky reefs, seagrass & weedy areas

Max Size:17cm


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CAAB distribution map