Nototheniidae
Giant Antarctic Cod ( Dissostichus mawsoni )
The Antarctic cod ( Nototheniidae ) are representative of the Perciformes ( Perciformes ), found in the waters of the southern hemisphere to the Antarctic. Here, their representatives dominate these regions and make up to 68 % of the fish fauna.
Features
Antarctic cod are eleven centimeters to 2.15 meters long. From their external appearance they resemble the cod ( Gadidae ) or the North Pacific Hexagrammiden. Your body is scaly and has one to three side lines. The first dorsal fin is supported by three to eleven spines, the second 25-42 soft rays. The swirl number is 45 to 59 The gill membranes forming a fold in the Isthmus. The mouth is vorstülpbar ( protaktil ).
Way of life
Antarctic cod are strictly stenothermal and survive only at a water temperature of -2.5 to 6 ° C. Most species of benthic ( on the sea floor ), some, like the plankton -eating Antarctic silverfish ( Pleuragramma antarcticum ) but also pelagic. Some species are also cyropelagisch, ie, they live under the ice shelf. The Antarctic cod have no swim bladder. Due to very high fat body tissue and a little ossified skeleton they nevertheless have sufficient buoyancy. As an adaptation to the cold, they have special antifreeze proteins in the blood. Moreover, their kidney is aglomerulär. With her no glomeruli are formed, the urine is not caused by ultrafiltration, but by secretion and diffusion processes in the renal tubules. Thus, the loss of small molecules is avoided.
Inside systematics
There are 56 species:
- Subfamily Nototheniinae genus Gobionotothen Gobionotothen acuta
- Gobionotothen barsukovi
- Gobionotothen gibberifrons
- Gobionotothen marionensis
- Lepidonotothen kempi
- Lepidonotothen larseni
- Lepidonotothen macrophthalma
- Lepidonotothen mizops
- Lepidonotothen nudifrons
- Lepidonotothen squamifrons
- Notothenia angustata Hutton, 1875
- Notothenia coriiceps
- Notothenia cyanobrancha
- Notothenia microlepidota Hutton, 1875
- Antarctic marble perch ( Notothenia rossii )
- Paranotothenia dewitti
- Patagonotothen brevicauda
- Patagonotothen canina
- Patagonotothen cornu cola
- Patagonotothen elegans
- Patagonotothen guntheri
- Patagonotothen Jordanian
- Patagonotothen kreffti
- Patagonotothen longipes
- Patagonotothen ramsayi
- Patagonotothen sima
- Patagonotothen squamiceps
- Patagonotothen tessellata
- Patagonotothen thompsoni
- Patagonotothen wiltoni
- Genus Aethotaxis Aethotaxis mitopteryx
- Patagonian toothfish ( Dissostichus eleginoides )
- Giant Antarctic Cod ( Dissostichus mawsoni )
- Gvozdarus svetovidovi
- Antarctic silverfish ( Pleuragramma antarcticum )
- Genus Cryothenia Cryothenia amphitreta
- Cryothenia peninsulae
- Pagothenia borchgrevinki
- Pagothenia brachysoma
- Trematomus bernacchii
- Trematomus eulepidotus
- Trematomus hansoni
- Trematomus lepidorhinus
- Trematomus loennbergii
- Trematomus newnesi
- Trematomus nicolai
- Trematomus pennellii
- Trematomus scotti
- Trematomus tokarevi
- Trematomus vicarius