''Notothenia microlepidota'', the black cod or small-scaled cod, 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 hor ...

, belonging to the

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

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

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

waters around

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

and

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 ...

. This species can reach a

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 . It is a

commercially Commerce is the large-scale organized system of activities, functions, procedures and institutions directly and indirectly related to the exchange (buying and selling) of goods and services among two or more parties within local, regional, nation ...

important species.

Taxonomy

''Notothenia microlepidota'' was first formally described in 1875 by the

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

-born New Zealand scientist Frederick Wollaston Hutton with the type locality given as

Dunedin Dunedin ( ; mi, Ōtepoti) is the second-largest city in the South Island of New Zealand (after Christchurch), and the principal city of the Otago region. Its name comes from , the Scottish Gaelic name for Edinburgh, the capital of Scotland. Th ...

and Dunedin and

Moeraki Moeraki is a small fishing village on the east coast of the South Island of New Zealand. It was once the location of a whaling station. In the 1870s, local interests believed it could become the main port for the north Otago area and a railwa ...

in New Zealand. The specific name ''microlepidota'' means "small scaled" which is though to be a reference to its small, numerous scales when compared to '' N. angustata'' which Woolaston described in the same

paper Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distributed ...

Description

''Notothenia microlepidota'' juveniles have a silvery appearance and their

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 se ...

is clearly forked. The adults have a less obviously forked caudal fin. The colour of the body is silver, yellow and reddish-brown. The body is covered in very small scales and there are two lateral lines which have a considerable overlap. The shortbased first

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 conv ...

has 6-7 spines, the second dorsal fin has 27-28 soft rays while the

nal fin NAL or Nal may refer to: In organizations: * Nal Sarovar Bird Sanctuary, in India * National Aerospace Laboratories, India * National Aerospace Laboratory of Japan * National Alliance of Liberals, a political party in Ghana * United States Natio ...

has 23-24 soft rays. This species attains a maximum

of .

Distribution and habitat

''Notothenia microlepidota'' is restricted to New Zealand and

in the southwestern Pacific Ocean. They have been found in depths of a few metres off Campbell Island and have been trawled at offshore.

Biology

In the

Campbell Plateau The Campbell Plateau is a large oceanic plateau south of New Zealand and the Chatham Rise. It originated in the Gondwanan breakup and is part of Zealandia, a largely submerged continent. The above sea level parts of the plateau — the Bounty ...

salp A salp (plural salps, also known colloquially as “sea grape”) or salpa (plural salpae or salpas) is a barrel-shaped, planktic tunicate. It moves by contracting, thereby pumping water through its gelatinous body, one of the most efficient ...

s are the most important prey, followed by

amphipods Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descri ...

(particularly '' Parathemisto gaudichaudii'') and percophidids.

Crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

s such as the portunid crab '' Nectocarcinus bennetti'' are also important prey. These prey items imply benthic feeding habits, typical for notothenids. Being a

subantarctic The sub-Antarctic zone is a region in the Southern Hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46° and 60° south of the Equator. The subantarctic region includes many islands ...

species, the black cod has special adaptations such as

antifreeze protein Antifreeze proteins (AFPs) or ice structuring proteins refer to a class of polypeptides produced by certain animals, plants, fungi and bacteria that permit their survival in temperatures below the freezing point of water. AFPs bind to small i ...

s in its

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...

, as well as

adipose Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular ...

tissues to offset its lack of a

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled Organ (anatomy), organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their curren ...

, giving it neutral buoyancy. The

sablefish The sablefish (''Anoplopoma fimbria'') is one of two members of the fish family Anoplopomatidae and the only species in the genus ''Anoplopoma''. In English, common names for it include sable (US), butterfish (US), black cod (US, UK, Canada), ...

, ''

Anoplopoma fimbria The sablefish (''Anoplopoma fimbria'') is one of two members of the fish family Anoplopomatidae and the only species in the genus ''Anoplopoma''. In English, common names for it include sable (US), butterfish (US), black cod (US, UK, Canada), ...

'', is occasionally called black cod, as well, but it is not a true cod. In New Zealand, the

Maori cod ''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 t ...

is also known as "black cod". They are a common prey item of seals.

References

* Tony Ayling & Geoffrey Cox, ''Collins Guide to the Sea Fishes of New Zealand'', (William Collins Publishers Ltd, Auckland, New Zealand 1982) {{Taxonbar, from=Q2517939 microlepidota Fish of the Pacific Ocean Marine fish of New Zealand Fish described in 1875 Taxa named by Frederick Hutton (scientist)