Cod icefishes | |
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Head of Antarctic toothfish (Dissostichus mawsoni) in McMurdo Sound | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Perciformes |
Suborder: | Notothenioidei |
Family: | Nototheniidae Günther, 1861 [1] |
Genera | |
see text |
Nototheniidae, the notothens or cod icefishes, is a family of ray-finned fishes, part of the suborder Notothenioidei which is traditionally placed within the order Perciformes. They are largely found in the Southern Ocean.
Nototheniidae was described as a family in 1861 by the German-born British ichthyologist Albert Günther with the type genus being Notothenia which had been described in 1844 by Sir John Richardson with the species Notothenia coriiceps which Richardson had also described in 1844 subsequently being designated as the type in 1862 by Theodore Nicholas Gill. [2] The name Notothenia means “coming from the south”, a reference to the Antarctic distribution of the genus. [3] They are traditionally placed in the order Perciformes together with their relatives, [4] Actual phylogenetic relationships among species of suborder Notothenioidei have not yet been determined with certainty. [5]
The following subfamilies [1] and genera are classified within the family Nototheniidae: [6] [2]
These subfamilies are not recognised in the 5th Edition of Fishes of the World . [4]
Nototheniidae fishes have fusiform or elongate and oblong bodies. They typically have two dorsal fins, the first having 3 to 11 spines and the second having 25-42 segmented fin rays. The anal fin is similar to the second dorsal fin and has 22 to 40 segmented rays. All but the last dorsal and anal fin rays are branched. The caudal fin is rounded to forked and the pectoral fins are large. The mouth is terminal and may be horizontal or angled with a protrusible upper jaw. There are no teeth on the roof of the mouth. in most species there are no spines on the preoperculum or operculum. Any scales are usually ctenoid although the spinules may be reduced or absent. They have between 1and 3 lateral lines. [7] They vary in size from. Total length of 11 cm (4.3 in) in Patagonotothen cornucola to 215 cm (85 in) in the Patagonian toothfish (Dissostichus eleginoides). [6]
Nototheniidae species are largely found in the Southern Ocean and are particularly abundant off the shores of Antarctica. [7] As the dominant Antarctic fish taxa, they occupy both sea-bottom and water-column ecological niches. [8]
Nototheniidae is a family of teleost fishes found mainly in the Southern Ocean, surrounding the continent of Antarctica. The family comprises about 50 species of fish that are adapted to living in the cold, nutrient-rich waters of the Southern Ocean. The Nototheniidae family includes some of the most ecologically and evolutionarily important fish in the Antarctic ecosystem, making them a crucial subject for scientific study.[ citation needed ]
Nototheniidae is a family of perciform fish that are primarily found in the Southern Ocean surrounding Antarctica, with some species also occurring in the sub-Antarctic regions of the southern hemisphere. They are known for their unique adaptations to the cold, such as the ability to produce antifreeze proteins to prevent their bodily fluids from freezing. The family includes over 100 species, making it the most diverse group of fish in the Southern Ocean. Nototheniidae inhabits a variety of habitats, from shallow coastal waters to deep ocean trenches. Many species are bottom-dwellers and can be found in rocky areas or on the seafloor, while others are pelagic and swim in the water column. Some species migrate seasonally to different habitats for feeding or spawning purposes. Due to their abundance in the Southern Ocean, Nototheniidae is an important part of the food chain for many marine predators, including seals, whales, and birds.[ citation needed ]
Nototheniidae species have no swim bladder, however, they have other depth-related adaptations, such as increased fatty tissues and reduced mineralization of the bones, resulting in a body density approaching neutral, to fill a variety of niches. [8] The spleen may be used to remove ice crystals from circulating blood. [9] [10] As the chilly Antarctic and sub-Antarctic waters of the Southern Ocean average −1 to 4 °C (30–39 °F), [11] most species of these regions produce antifreeze glycoproteins to prevent the formation of ice crystals in blood and other body fluids. [12]
The concentration of antifreeze glycoproteins can vary with differing environmental conditions, such as colder environments caused by location. Larger amounts of the proteins have been found in species with habitats in higher latitudes, due to the higher expression of the protein and longer degradation time compared to relatives in more temperate regions, portraying flexible temperature regulation. [13]
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-mouthed/broad-headed morph. [14]
Nototheniidae species are the major fish resource in the Southern Ocean, many notothens are under increasing pressure from commercial fishing, particularly the Patagonian toothfish and the Antarctic toothfish. [15]
Notothenia angustata, the Maori chief or black cod, 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
Notothenioidei is one of 19 suborders of the order Perciformes. The group is found mainly in Antarctic and Subantarctic waters, with some species ranging north to southern Australia and southern South America. Notothenioids constitute approximately 90% of the fish biomass in the continental shelf waters surrounding Antarctica.
Icefish may mean:
Bovichtidae, the temperate icefishes or thornfishes, is a family of marine ray-finned fishes, classified in the suborder Notothenioidei of the order Perciformes. They are native to coastal waters off Australia, New Zealand, and South America.
The bald notothen, also known as the bald rockcod, 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.
Notothenia is a genus of marine ray-finned fishes belonging to the family Nototheniidae, the notothens or cod icefishes with the species in this genus often having the common name of rockcod. They are native to the Southern Ocean and other waters around Antarctica.
Dissostichus, the toothfish, is a genus of marine ray-finned fish belonging to the family Nototheniidae, the notothens or cod icefish. These fish are found in the Southern Hemisphere. Toothfish are marketed in the United States as Chilean sea bass or less frequently as white cod. "Chilean sea bass" is a marketing name coined in 1977 by Lee Lantz, a fish wholesaler who wanted a more attractive name for selling the Patagonian toothfish to Americans. In 1994, the U.S. Food and Drug Administration (FDA) accepted "Chilean sea bass" as an "alternative market name" for Patagonian toothfish. The toothfish was remarkably successful in the United States, Europe and Asia, and earned the nickname "white gold" within the market. Toothfish are vital to the ecological structure of Southern Ocean ecosystems. For this reason, on 4 September a national day is dedicated to the toothfish in South Georgia.
Paranotothenia magellanica, also known as Magellanic rockcod, Maori cod, blue notothenia or orange throat 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. "Maori chief" and "black cod", sometimes used for this species, usually refer to fishes from the related genus Notothenia. Being a perciform fish, it is unrelated to the true cods of the order Gadiformes. This species is commercially important as a food fish.
Channichthys is a genus of marine ray-finned fish belonging to the family Channichthyidae, the crocodile icefishes. They are native to the Southern Ocean.
The emerald rockcod, 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.
Trematomus is a genus of marine ray-finned fishes, belonging to the family Nototheniidae, the notothens or cod icefishes. These fishes occur in the Southern Ocean.
Cryothenia is a genus of marine ray-finned fishes, belonging to the family Nototheniidae, the notothens or cod icefishes. They are native to the Southern Ocean.
Gobionotothen is a genus of marine ray-finned fishes belonging to the family Nototheniidae, the notothens or cod icefishes. They are native to the Southern Ocean.
Gvozdarus is a genus of marine ray-finned fishes belonging to the family Nototheniidae, the notothens or cod icefishes. It is native to the Southern Ocean.
The grey rockcod, also known as the grey notothen, stripe-eyes notothen or stripe-eyed rockcod, 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. The grey rockcod feeds mainly on macrozooplankton and is of minor importance to commercial fisheries. It is the only species in the genus Lepidonotothen.
The toad notie, or toad notothen, is a species of marine ray-finned fish, belonging to the family Nototheniidae, the notothens or cod icefishes. It is native to the Indian sector of the Southern Ocean.
Paranotothenia is a genus of marine ray-finned fishes belonging to the family Nototheniidae, the notothens or cod icefishes. These fishes are native to the Southern Ocean.
Patagonotothen is a genus of marine ray-finned fishes, belonging to the family Nototheniidae, the notothens or cod icefishes. They are native to the southeast Pacific Ocean, southern Atlantic Ocean and the Southern Ocean.
Notothenia coriiceps, also known as the black rockcod, Antarctic yellowbelly rockcod, or Antarctic bullhead notothen, is a species of marine ray-finned fish, belonging to the family Nototheniidae, the notothens or cod icefishes. It is widely spread around the Antarctic continent. Like other Antarctic notothenioid fishes, N. coriiceps evolved in the stable, ice-cold environment of the Southern Ocean. It is not currently targeted by commercial fisheries.
Notothenia trigramma is a species of marine ray-finned fish, belonging to the family Nototheniidae, the notothens or cod icefishes. It occurs in the southwestern Atlantic Ocean.