Emerald notothen
The emerald rockcod (Trematomus bernacchii), also known as the emerald notothen is a species of marine ray-finned fish belonging to the family Nototheniidae, the notothens or cod icefishes. It is native to the Southern Ocean where it is a commercially important species.
This species is mostly brown in color with darker spots. The first dorsal fin contains 4-6 spines, the second dorsal fin has 34-39 soft rays and the anal fin has 31-35 soft rays. Females of this species can reach a length of 35 cm (14 in), while males only reach 28 cm (11 in). The maximum reported age for this species is 10 years.
This species is native to the Southern Ocean on the seafloor at depths from very shallow waters to 700 m (2,300 ft). It is adapted to living in waters of extremely low temperature (-1.86 °C mean temperature in McMurdo Sound). It consumes various invertebrates and small fishes and also is known to feed on some algae. Their foraging techniques make them the primary predators of the medium-sized population of the Antarctic scallop, Adamussium colbecki.
