Latin name

Trematomus loennbergii

Other name

Trematomus loennbergii

Identification

The body of the Scaly Rockcod is elongated, moderately compressed at the sides, not high; its height is about 19-25% of standard body length. The head is moderately long, about 27-29% of standard length. The mouth is terminal. The upper jaw is retractable; its length is 36-43% of the length of the head. The eye is large, 28-37% of the length of the head. The interorbital space is relatively narrow, 16-27% of head length.

The body is covered mainly with ctenoid scales; cycloid scales cover the belly, the thorax in front of the pectoral fins, and the lower part of the head. The head is almost entirely covered with scales, except for the anterior part of the snout, the lower jaw, and the intergillary space.

Gill membrane rays 5-6; total number of stamens in the outer row of the first gill arch 20-24, of which in the lower part - 13-15, in the upper part - 6-10 gill stamens; transverse rows of scales on the body 64-80; number of tubular scales in the dorsal lateral line 41-47; medial lateral line is short, counts 6-19 tubular scales; total number of vertebrae 50-54, of which trunk 16-18 and caudal 33-37.

Features of fish fins

The first dorsal fin has 5-7 flexible barb rays, the second dorsal fin has 33-35 articulated rays, the anal fin has 33-35 articulated rays (1-2 rays more than the second dorsal fin), and the pectoral fin has 26-29 rays. 

Fish colouring

The general body coloration of live adult fish caught at great depths is blackish, with a metallic blue-greenish sheen on the gill covers. Fish fixed in formalin and alcohol have a uniform brown coloration with no noticeable spots or stripes. The first dorsal and caudal fins are black or blackish. Other fins are generally lighter in color, blackening toward the ends. The mouth and gill cavities are black. Live fish from shallower depths may be lighter - tan, with a darker back and 4-7 dark stripes on the sides of the body.

Distribution

Widespread circumpolar on the shelf and upper bathyal of the marginal seas of Antarctica and around the Antarctic Peninsula. Southern Ocean: Coasts of the Antarctic Peninsula, Queen Mary, Adelaide, South Victoria, Davis, Ross, Amundsen and Weddell Seas.

Habitat

Demersal - an epibenthic species that lives mainly on the bottom surface and sporadically ascends to the benthic layer of the pelagial in search of food. 

Size

Medium sized fish. Maximum length : 30.0 cm. Total length : 20.0 cm. Maximum declared weight : 357.40 g.

Behavior

Occurs in a fairly wide range of depths from 65 to 832 meters, mostly deeper than 300 meters.

Food and feeding habits

It feeds on zooplankton - amphipods, mainly Orchomene plebs, free-living polychaetes, isopods, other small crustaceans and small fish.

Reproduction

In the Weddell Sea it spawns in the fall. Postlarvae with a standard length of 25-30 mm have been recorded off the Antarctic Peninsula in March. 

Fishing

This species is of no interest to fisheries.

Relationship with a person

Harmless.