Bluebottle-fish, Nomeus gronovii (Gmelin, 1789)
Portuguese Man-o-war Fish, Shepherd Fish
Introduction
Young Bluebottle-fish are pelagic, but adults are demersal. The juveniles live among the tentacles of the blue bottle, Physalia,
Identification
The Bluebottle-fish has a compressed body and a large forked caudal fin. The pelvic fins are large and fan-like.
Juveniles are bright blue on the back and silver on the sides. There are blue spots and blotches on the body and fins. Adults are usually dark brown.
Nomeus gronovii is only species in the genus Nomeus.
Habitat
Young Bluebottle-fish are pelagic, but adults are demersal. The juveniles live among the tentacles of the blue bottle, Physalia.
Distribution
It occurs in tropical and some temperate continental shelf waters circumglobally.
In Australia, the Bluebottle-fish is known from the offshore islands of north-western Western Australia, around the tropical north of the country and down the east coast to Bass Strait, Victoria. It has also been recorded from Lord Howe Island.
The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Click on the map for detailed information. Source: Atlas of Living Australia.
Feeding and diet
Juveniles are believed to eat small pelagic invertebrates and may nibble on the blue bottle’s tentacles.
References
- Hoese, D.F., Bray, D.J., Paxton, J.R. & G.R. Allen. 2006. Fishes. in Beesley, P.L. & A. Wells. (eds) Zoological Catalogue of Australia. Volume 35. ABRS & CSIRO Publishing: Australia. parts 1-3, pages 1-2178.
- McDowall, R.M. Family Nomeidae. in Gomon, M.F., Glover, C.J.M. & R.H. Kuiter (Eds). 1994. The Fishes of Australia's South Coast. State Print, Adelaide. Pp. 992.
- Kuiter, R.H. 2000. Coastal Fishes of South-eastern Australia. Gary Allen. Pp. 437.