Description
A specimen of Dissostichus mawsoni the Antarctic toothfish (Notothenioidei, Nototheniidae)captured and photographed underwater in McMurdo Sound, Antarctica. This fish was approximately 100 lbs. D. mawsoni is closely related to and resembles D. eleginoides, commonly called the Chilean Sea Bass, and both fishes are probably marketed under that name. Both species may be at risk for overfishing. Photograph by Paul Cziko, supported by US-NSF through the DeVries-Cheng Lab at the University of Illinois, Urbana-Chamnpaign
Source: https://commons.wikimedia.org/wiki/File:Dmawsoni_Head_shot.jpg

Dissostichus mawsoni, the Antarctic toothfish, is a species of cod icefish native to the Southern Ocean. It is often mistakenly referred to as an Antarctic cod, consistent with the misnaming of other notothenioid Antarctic fish as rock cods. However, notothenioid fishes are unrelated to cods, which are in another taxonomic order, the Gadiformes. The generic name Dissostichus is from the Greek dissos (twofold) and stichus (line) and refers to the presence of two long lateral lines, which are very important to the species’ ecology. The common name "toothfish" refers to the presence of biserial dentition in the upper jaw, thought to give it a shark-like appearance. The habitat of the Antarctic toothfish is in subzero degree water below latitude 60°S. Order: Perciformes, Family: Nototheniidae, Genus: Dissostichus, Species: Dissostichus mawsoni Norman, 1937.