Big-belly seahorse  (Hippocampus abdominalis)

This seahorse is found in the south-west Pacific around Australia and New Zealand (2). It is known in Australia from Newcastle, New South Wales southwards, throughout Victoria, Tasmania and westwards as far as the northern Great Australian Bight in South Australia (9). In New Zealand, it is widespread around both North and South Islands (3). It has been suggested that the populations that make up this species are actually two separate species. However, this taxonomic splitting is still quite contentious and there is little evidence for the existence of two species (10).

Inhabits harbours and sheltered coastal bays (3). They can be found amongst algae, seagrasses and around rocky reefs in fairly shallow water. In deeper water they typically attach to sponges (2). Unlike most seahorse species, the big-belly seahorse is a relatively strong swimmer and has been known to swim over hundreds of meters in the course of a day (11). Adults are also known to occur in open water and to raft on algal rafts and seagrass. Artificial structures appear to be important habitats for this species - in particular jetties, nets and salmon cages (10).