ANIMAL SPECIES:River Blackfish, Gadopsis marmoratus (Richardson 1848)
The River Blackfish may be pale green, yellowish, brown or black in colour. It usually has a marbled pattern with larger dark blotches. The underside is pale yellow, blue or purple-grey. The upper jaw is longer than the lower. The pelvic fins are positioned under the opercular openings. Both pelvic fins consist of a single branched ray. The spinous portion of the dorsal fin is lower than the soft-rayed portion.
Identification
The River Blackfish may be pale green, yellowish, brown or black in colour. It usually has a marbled pattern with larger dark blotches. The underside is pale yellow, blue or purple-grey. The upper jaw is longer than the lower.
The pelvic fins are positioned under the opercular openings. Both pelvic fins consist of a single branched ray. The spinous portion of the dorsal fin is lower than the soft-rayed portion.
Size range
The River Blackfish grows to 60 cm in length, but individuals this size are uncommon. It is usually seen at sizes up to 45 cm.Similar Species
A second species in the genus Gadopsis, is also found in freshwater streams of south-eastern Australia. The Two-spined Blackfish, G. bispinosus Sanger 1984 has a more restricted distribution. This species has only two spines in the dorsal fin, while the River Blackfish has 6 to 13.Distribution
The River Blackfish occurs in south-eastern Australia.
Habitat
The species occurs in freshwater streams, but has a reduced distribution because of habitat degradation. It is still common in some areas.
In New South Wales and the Australian Capital Territory, the species is mostly found in westerly flowing streams. In South Australia it is restricted to an area in the south east of the state. It occurs widely in Victoria, and is found in northern and southern Tasmania.
Behaviour and adaptations
Feeding and Diet
It eats insects, crustacea and sometimes other fishes.
Other behaviours and adaptations
The River Blackfish is a nocturnal species.
Classification
- Species:
- marmoratus
- Genus:
- Gadopsis
- Family:
- Gadopsidae
- Class:
- Actinopterygii
- Subphylum:
- Vertebrata
- Phylum:
- Chordata
- Kingdom:
- Animalia
References
- Allen, G.R. 1989. Freshwater Fishes of Australia. T.F.H. Publications. Pp. 240.
- Jackson, P.D, Koehn, J.D., Lintermans, M & A.C. Sanger. in McDowall, R.M. 1996. Freshwater Fishes of South-Eastern Australia. Reed Books. Pp. 247.
- Merrick, J.R. & G.E. Schmida. 1984. Australian Freshwater Fishes. Biology and Management. John R. Merrick. Pp. 409.
Would you like to add a comment?
Sign up to add comments and find out more about the other benefits you can enjoy.
Would you like to add a tag?
Sign up to add tags and find out more about the other benefits you can enjoy.
what's on
18 Mar 08
See, hear, touch and even smell the world of dinosaurs.
Level 2, Dinosaurs Exhibition
Support us
Help us continue to provide quality research, education, community programs and exhibitions.
Online Shop
Featuring a selection of products relating to the collections.
Australian Museum Members
Join today to come to the Museum for free and enjoy many other benefits.
AMBS
Australian Museum Business Services - Ecological, archaeological and heritage consulting.
Museum as a Venue
We have many unique venues ideal for dinner, cocktails, weddings and conferences.