Ribbonfish

Large oceanic fishes with brilliant silvery skin and bright red fins. Southern Ribbonfish have a very long, highly compressed body that tapers to a very narrow tail base, large eyes, a large highly protrusible mouth, and a long-based dorsal fin extending from the top of head to the tail base, with a high crest at the front in young. The pelvic fins are long and fan-like in juveniles, and reduced to small tubercles in adults. 

Standard Common Name
Southern Ribbonfish

Identification
The Southern Ribbonfish has a highly compressed body that tapers posteriorly. It has very large eyes and a large protrusible mouth. The dorsal fin extends nearly the full length of the fish.
It is grey to brown above and sometimes paler below. The gill openings have white borders.

This species lacks scales but has dermal tubercles. The tubercles on the ventral margin are enlarged. Those along each side of the dorsal fin pterigiophores are arranged in rows (see bottom image). 

The Southern Ribbonfish is silvery in colour but parts of the head may be black. 

A single species of Trachipterus is currently recognised from Australian waters. The names T. jacksonensis and T. arawatae have been used in different publications for Australian specimens. Taxonomic work is required to clarify this issue. Juveniles have with several large black blotches on either side. 

Size range
The species grows to at least 2 m in length.

Distribution
The Southern Ribbonfish occurs in marine waters of South Africa and Australia. In Australia it is known from southern Queensland and around the south-east of the country to eastern South Australia. 

Habitat
The species is usually caught in trawls from deep water but is also occasionally seen washed ashore after storms or even on the surface. 

Feeding and Diet 
Dietary items reported for fishes in the genus include bony fishes, cephalopods and planktonic crustaceans. They may be preyed upon by Lancetfishes. 
Other behaviours and adaptations 
Hagfishes are able to produce large quantities of slime. When the concentrated slime solution is ejected from the slime glands it mixes with seawater and expands to several hundred times its initial volume. A bucket of water can be turned into slime in a matter of minutes after the inclusion of a hagfish. These fishes can tie their bodies in a knot and then run the knot down the length of the body to remove slime.

Classification 
Species: jacksonensis 
Genus: Trachipterus 
Family: Trachipteridae
Order: Lampridiformes
Class: Actinopterygii