''Paranotothenia magellanica''), also known as Magellanic rockcod, Maori cod, blue notothenia or orange throat notothen, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

, belonging to the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Nototheniidae : ''In some scientific literature, the term "cod icefish" is used to identify members of this family. This should not be confused with the term "icefish," which refers to the "white-blooded" fishes of the family Channichthyidae. See Icefish (disam ...

, the notothens or cod icefishes. It is native to the

Southern Ocean The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the World Ocean, generally taken to be south of 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-small ...

. " Maori chief" and " black cod", sometimes used for this

, usually refer to fishes from the related

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Notothenia''. Being a

perciform Perciformes (), also called the Percomorpha or Acanthopteri, is an order or superorder of ray-finned fish. If considered a single order, they are the most numerous order of vertebrates, containing about 41% of all bony fish. Perciformes means " ...

fish, it is unrelated to the true

cod Cod is the common name for the demersal fish genus '' Gadus'', belonging to the family Gadidae. Cod is also used as part of the common name for a number of other fish species, and one species that belongs to genus ''Gadus'' is commonly not call ...

s of the order

Gadiformes Gadiformes are an order of ray-finned fish, also called the Anacanthini, that includes the cod. Many major food fish are in this order. They are found in marine waters throughout the world and the vast majority of the species are found in tempe ...

. This species is commercially important as a food fish.

Taxonomy

''Paranotothenia magellanica'' was first formally described as ''Gadus magellanicus'' in 1801 by the German naturalist

Johann Reinhold Forster Johann Reinhold Forster (22 October 1729 – 9 December 1798) was a German Reformed (Calvinist) pastor and naturalist of partially Scottish descent who made contributions to the early ornithology of Europe and North America. He is best known ...

with the type locality given as the

Straits of Magellan The Strait of Magellan (), also called the Straits of Magellan, is a navigable sea route in southern Chile separating mainland South America to the north and Tierra del Fuego to the south. The strait is considered the most important natural pas ...

. The Russian ichthyologist Arkady Vladimirovich Balushkin placed it in its own

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

genus, '' Paranotothenia'', in 1976. A second species '' P. dewitti'' was described by Balushkin in 1990. The specific name refers to the type locality.

Description

''Paranotothenis magellanica'' has a wide head with a short snout and a mouth which reaches as far back as the middle of the eye. The front part of the snout is steep, with a prominent bulge before the eye. The eyes are noticeable more widely spaced than those of ''Notothenia''. The wide cranium has a rough upper surface with lost of crests, bumps and pits. The crest over the eye extends rearwards quite far. The head is largely unscaled, although there are small patches of scales to the rear of the eyes. The majority of the body scales are non-

ctenoid A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as ...

. The

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

ranges from forked in juveniles, emarginate or infrequently slightly rounded in larger individuals to emarginate in the largest fishes found off Antarctica. They have large scales large with the upper lateral line having 36 to 46 tubed scales and the middle lateral line having 5 to 14 tubed scales. There are two

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

s, the first is short-based and contains 3 to 6 spines, the second dorsal fin has 28-31 soft rays while the anal fin has 22-25 soft rays. This species attains a maximum

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

of , although has been reported. The upper body is dark blue, greyish-green, brown or black while the abdomen is cream, gold-yellow or reddish. The gill membranes can be orange or red.

Distribution and habitat

''Paranotothenia magellanica'' is found in the Southern Ocean. It occurs off the southern tip of South America and off the

Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouze ...

, South Georgia,

South Orkney The South Orkney Islands are a group of islands in the Southern Ocean, about north-east of the tip of the Antarctic Peninsula South Shetland The South Shetland Islands are a group of Antarctic islands with a total area of . They lie about north of the Antarctic Peninsula, and between southwest of the nearest point of the South Orkney Islands. By the Antarctic Treaty of 195 ...

, Prince Edward, Crozet,

Kerguelen The Kerguelen Islands ( or ; in French commonly ' but officially ', ), also known as the Desolation Islands (' in French), are a group of islands in the sub-Antarctic constituting one of the two exposed parts of the Kerguelen Plateau, a large ...

, Heard and Macquarie islands as well as around southern New Zealand as far north a Kaikoura and around associated islands, it is rare in the Ross Sea. It is found from the surface down to . Large individuals in Antarctc waters are apparently pelagic. Adults elsewhere appear to stay close to shore and may also be pelagic in habit to some extent as they are rarely captured in large bottom trawls.

Biology

''Paranotothenia magellanica'' has

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...

fingerlings which have been captured some distance from land over deep water. Off the Kerguelen Islands spawning appears to occur in April and May, a feamle may lay 60,000-70,000 pelagic eggs which are about 0.8 mm in diameter. Magellanic rockcod feed have been recorded to eat the algae, amphiipos, the crab '' Halicarcinus planatus'', the

squat lobster Squat lobsters are dorsoventrally flattened crustaceans with long tails held curled beneath the cephalothorax. They are found in the two superfamilies Galatheoidea and Chirostyloidea, which form part of the decapod infraorder Anomura, alongsi ...

'' Munida gregaria'', copepods, isopods, hydrozoans, larval crustaceans and molluscs, including the bivalve '' Gaimardia trapesina''. The Magellanic cod is the most abundant inshore fish in the waters off Marion Island and off

Macquarie Island Macquarie Island is an island in the southwestern Pacific Ocean, about halfway between New Zealand and Antarctica. Regionally part of Oceania and politically a part of Tasmania, Australia, since 1900, it became a Tasmanian State Reserve in 197 ...

Fisheries

''Paranotothenia magellanica'' is caught as a foodfish.

References

* * Tony Ayling & Geoffrey Cox, ''Collins Guide to the Sea Fishes of New Zealand'', (William Collins Publishers Ltd, Auckland, New Zealand 1982) {{Taxonbar, from=Q2259508 Maori cod Commercial fish Fish described in 1801