Animal Species:Grey Knifefish, Bathystethus cultratus (Forster, 1801)

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.

Size range

The species grows to about 30 cm in length.

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.

Distribution by collection data

Ozcam map of Grey Knifefish specimens in the Australian Museum.

What does this mean?

Feeding and Diet

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

Classification

Species:

cultratus

Genus:

Bathystethus

Family:

Kyphosidae

Order:

Perciformes

Class:

Actinopterygii

Subphylum:

Vertebrata

Phylum:

Chordata

Kingdom:

Animalia

What does this mean?

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.

Mark McGrouther , Collection Manager, Ichthyology
Last Updated: 12 October 2012

Tags Fishes, Ichthyology, Grey Knifefish, Bathystethus cultratus, Kyphosidae, blue, 'normal fish', 10 cm - 30 cm, no pattern, coastal, marine, adult,