Grey Knifefish, Bathystethus cultratus (Forster, 1801)

Scientific name: Bathystethus cultratus
Grey Knifefish, Bathystethus cultratus Click to enlarge image
Grey Knifefish below the breaking waves (water depth 20m) at South Solitary Island, Coffs Harbour, New South Wales, April 2006. Image: Sascha Schulz
© Sascha Schulz

Fast Facts

  • Classification
    Genus
    Bathystethus
    Species
    cultratus
    Family
    Kyphosidae
    Order
    Perciformes
    Class
    Actinopterygii
    Subphylum
    Vertebrata
    Phylum
    Chordata
    Kingdom
    Animalia
  • Size Range
    The species grows to about 30 cm in length.

Introduction

The Grey Knifefish is a compressed silvery-grey fish that occurs in Australia and New Zealand.

Identification

The Grey Knifefish is a compressed fish that has a low spinous dorsal fin, followed by a long-based soft-rayed dorsal fin. The second dorsal and anal fins are covered with scales. The body scales are silvery-grey. It lacks teeth.

Distribution

The species occurs in Australia and New Zealand. In Australia it is known from northern to central New South Wales and from Norfolk Island and Lord Howe Island.

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 Grey Knifefish is a fast swimmer that is usually seen near the surface feeding on plankton.

References

  1. Allen, G.R., Hoese, D.F.,Paxton, J.R., Randall, J.E., Russell, B.C., Starck, W.A.,Talbot, F.H. & Whitley, G.P. (1976). Annotated checklist of the fishes of Lord Howe Island. Records of the Australian Museum. 30(15): 365-454.
  2. Paulin, C., Stewart, A., Roberts, C. & P. McMillan. 1989. New Zealand fish: a complete guide. National Museum of New Zealand Miscellaneous Series 19. Pp. 279.