Animal Species:Bigbelly Seahorse, Hippocampus abdominalis Lesson, 1827

The Bigbelly Seahorse has a low coronet, and as the common name implies, adults have very big 'bellies'. They live in a variety of habitats including shallow areas of seagrass to deeper sponge gardens.

Bigbelly Seahorse, Hippocampus abdominalis

Bigbelly Seahorse, Hippocampus abdominalis
Photographer: Richard Vevers © Richard Vevers

Standard Common Name

Bigbelly Seahorse

Alternative Name/s

Eastern Potbelly Seahorse


The Bigbelly Seahorse has a low coronet, and as the common name implies, adults have very big 'bellies'.

The colouration of the Bigbelly Seahorse is variable. It can be brown, orange, white, yellow, grey or even mottled. It sometimes has dark spots and long filaments on the head or body. The colouration appears correlated with habitat.

Size range

It grows to about 18 cm in length.

Similar Species

The Bigbelly Seahorse looks similar to the Potbelly Seahorse, Hippocampus bleekeri. The two species can be separated by the Bigbelly Seahorse's shorter snout, the more common presence of head filaments in the Potbelly Seahorse, and their disjunct distributions.


It occurs in Australia and New Zealand. In Australia it is only known from the central to southern coasts of New South Wales.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums.  Source: Atlas of Living Australia.

Hippocampus abdominalis

Distribution by collection data

Ozcam map of Bigbelly Seahorse specimens in the Australian Museums.

What does this mean?


The Bigbelly Seahorse lives in a range of habitats from shallow areas of seagrass to deeper sponge gardens.



What does this mean?


  1. Edgar, G.J. 1997. Australian Marine Life; the plants and animals of temperate waters. Reed Books. Pp. 544.
  2. Hutchins, B. & R. Swainston. 1986. Sea Fishes of Southern Australia. Complete Field Guide for Anglers and Divers. Swainston Publishing. Pp. 180.
  3. Kuiter, R.H. 1996. Guide to Sea Fishes of Australia. New Holland. Pp. 433.
  4. Kuiter, R.H. 2000. Coastal Fishes of South-eastern Australia. Gary Allen. Pp. 437.
  5. Kuiter, R.H. 2000. Seahorses, Pipefishes and their Relatives. A Comprehensive Guide to Syngnathiformes. TMC Publishing Pp. 240.
  6. Kuiter, R.H. 2001. Revision of the Australian Seahorses of the Genus Hippocampus (Syngnathiformes: Syngnathidae) with Descriptions of Nine New Species. Records of the Australian Museum. 53: 293-340.
  7. Lourie, S.A., Vincent, A.C.J.& H.J. Hall. 1999. Seahorses: an identification guide to the world's species and their conservation. Project Seahorse, London. Pp. 214.

Mark McGrouther , Collection Manager, Ichthyology
Last Updated:

Tags fish, ichthyology, Bigbelly Seahorse, Hippocampus abdominalis, weed, seaweed, seagrass, sponge garden, Syngnathidae, yellow, black spots, 10 cm - 30 cm, marine, adult,