Nototheniidae

Cod icefishes
Head of Antarctic Cod (Dissostichus mawsoni) in McMurdo Sound
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Superclass:	Osteichthyes
Class:	Actinopterygii
Subclass:	Neopterygii
Infraclass:	Teleostei
Superorder:	Acanthopterygii
Order:	Perciformes (disputed)
Suborder:	Notothenioidei
Family:	Nototheniidae
Genera
13, see text

The cod icefishes or nothothens are the family Nototheniidae of acanthopterygian fishes, containing about 50 species in 13 genera. They are traditionally placed in the perciform assemblage together with their relatives, but like every lineage in the "Perciformes" their actual relationships are not yet determined with certainty.

They are largely found in the Southern Ocean and off the coast of Antarctica. As the dominant Antarctic fish taxa, they occupy both sea bottom and water column ecological niches. Although lacking a gas bladder, they have undergone a depth-related diversification, such as increase in fatty tissues and reduced mineralization of the bones, resulting in a body density approaching neutral, to fill a variety of water column niches. It is thought that the spleen may be used to remove ice crystals from circulating blood. As the chilly subantarctic waters averages –1 to 4 degrees Celsius, most Antarctic species have antifreeze glycoproteins in their blood and other body fluids.

Some species exhibit polymorphism, for example, the circum-Antarctic Trematomus newnesi exists as two morphs in the Ross Sea, the typical morph and a large mouth/broad headed morph.

As the major fish resource in the Southern Ocean, nototheniids are under increasing pressure from commercial fishing.

Genera and selected species

Gobionotothen gibberifrons

Emerald Rockcod (Trematomus bernacchii)

Aethotaxis Aethotaxis mitopteryx Cryothenia Cryothenia amphitreta Cryothenia peninsulae Dissostichus Dissostichus eleginoides – Patagonian Toothfish Dissostichus mawsoni – Antarctic Cod Gobionotothen Gobionotothen acuta Gobionotothen barsukovi Gobionotothen gibberifrons Lönnberg, 1905 Gobionotothen marionensis Gvozdarus Gvozdarus svetovidovi Lepidonotothen Lepidonotothen kempi Lepidonotothen larseniLönnberg, 1905 – Painted notie Lepidonotothen macrophthalma Lepidonotothen mizops Lepidonotothen nudifrons Lepidonotothen squamifrons Notothenia (5-7 species) Nototheniops Pagothenia Pagothenia borchgrevinki – Bald Notothen Pagothenia brachysoma Paranotothenia Paranotothenia dewitti Paranotothenia magellanica – Maori Cod, Magellanic Rockcod, Blue Notothen, Orangethroat Notothen, "black cod", "Maori chief"

Patagonotothen (all non-Antarctic) Patagonotothen brevicauda Patagonotothen canina Patagonotothen cornucola Patagonotothen elegans Patagonotothen guntheri Patagonotothen jordani Patagonotothen kreffti Patagonotothen longipes Patagonotothen ramsayi Patagonotothen sima Patagonotothen squamiceps Patagonotothen tessellata Patagonotothen thompsoni Patagonotothen wiltoni Pleuragramma – Antarctic Silverfish Trematomus Trematomus bernacchii – Emerald Rockcod Trematomus eulepidotus Trematomus hansoni Trematomus lepidorhinus Trematomus loennbergii Trematomus newnesi Trematomus nicolai Trematomus pennellii Trematomus scotti Trematomus tokarevi Trematomus vicarius

References

• Froese, Rainer, and Daniel Pauly, eds. (2005). "Nototheniidae" in FishBase. November 2005 version.