Hammerjaw, Omosudis lowei (Günther, 1887) Click to enlarge image
A Hammerjaw trawled during the NORFANZ expedition at a depth between the surface and 1275m in international waters south-east of Norfolk Island, May 2003 (NMNZ P.38953). Image: Mark McGrouther
© NORFANZ Founding Parties

Fast Facts

  • Classification
    Species
    lowii
    Genus
    Omosudis
    Family
    Omosudidae
    Order
    Aulopiformes
    Class
    Actinopterygii
    Subphylum
    Vertebrata
    Phylum
    Chordata
    Kingdom
    Animalia
  • Size Range
    The species grows to 30 cm in length.

Introduction

The Hammerjaw has an iridescent silvery-bronze colour. It is a predator of fishes and squid.

Identification

The Hammerjaw has a strongly compressed body that lacks scales. It has a very large mouth with a truncate lower jaw. There is at least one huge fang on the lower jaw and one to four fangs on the palatines. A short based dorsal fin is positioned behind the middle of the body. A dorsal adipose fin is positioned above the posterior anal fin rays. There is a dermal keel present on the caudal peduncle. The species has an iridescent silvery-bronze colour.


Hammerjaw, Omosudis lowei (Günther, 1887)
A Hammerjaw trawled during the NORFANZ expedition at a depth between the surface and 1275 m in international waters south-east of Norfolk Island, May 2003 (NMNZ P.38953). Image: Mark McGrouther
© NORFANZ Founding Parties

Habitat

It occurs in mesopelagic and bathypelagic depths in temperate and tropical marine waters worldwide.

Distribution

In Australia it is known from scattered localities off New South Wales, and off south-eastern and north-western Western Australia.

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



Feeding and diet

The Hammerjaw is a predator of fishes and squid.

References

  1. Gomon, M.F. 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.
  2. 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.
  3. Paxton, J.R. & V.H. Niem 1999. Omosudidae. In Carpenter, K.E. & V.H. Niem (Eds). FAO Species Identification Guide for Fishery Purposes. The Living Marine Resources of the Western Central Pacific. Volume 3. Batoid fishes, chimaeras and bony fishes part 1 (Elopidae to Linophrynidae). FAO, Rome. Pp. iii-vi, 1398-2068.