The Cosmopolitan Rubyfish has a highly protrusible mouth. It occurs in temperate continental shelf and slope waters.
The Cosmopolitan Rubyfish is a moderately elongate species that has a single continuous dorsal fin and a strongly forked tail. Fishes in the family Emmelichthyidae are often called Bonnetmouths. This name refers to the highly protrusible mouth.
Two species of Plagiogeneion are known from Australian waters. The second species, the Bigscale Rubyfish, Plagiogeneion macrolepis, looks similar to the Cosmopolitan Rubyfish, but has larger scales (48-51 scales in the lateral line versus 67-74). The Bigscale Rubyfish occurs from the Great Australian Bight to south-western Western Australia.
The Cosmopolitan Rubyfish occurs in temperate continental shelf and slope waters (down to 550 m) of the Eastern Atlantic Ocean and Indo-West Pacific. In Australia it is known from the central coast of New South Wales to Bass Strait.
The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Source: Atlas of Living Australia.
- Heemstra, P.C. & J.E. Randall. 1977. A revision of the Emmelichthyidae (Pisces: Perciformes). Australian Journal of Marine and Freshwater Research. 28: 361-396.
- May, J.L. & J.G.H. Maxwell. 1986. A field guide to trawl fish from temperate waters of Australia. CSIRO Division of Fisheries Research. Pp. 492.