Marbled rockcod
| Marbled rockcod | |
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Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Perciformes |
| Family: | Nototheniidae |
| Genus: | Notothenia |
| Species: | N. rossii
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| Binomial name | |
| Notothenia rossii J. Richardson, 1844[1]
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| Synonyms[1] | |
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The marbled rockcod (Notothenia rossii) 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 can be found at depths from 5 to 350 m (16 to 1,148 ft). This is a commercially important species.[2]
Taxonomy
[edit]The marbled rockcod was first formally described in 1844 by the Scottish naval surgeon, naturalist and Arctic explorer John Richardson with no type locality given, although it is thought likely to be Kerguelen Island.[3] Richardson gave it the specific name rossii which honours James Clark Ross, the leader of the Ross expedition, a scientific expedition by the vessels HMS Erebus and HMS Terror to survey and explore the coasts of Antarctica.[4]
Description
[edit]The marbled rockcod can reach a length of 92 cm (36 in), though a more common length is around 50 cm (20 in). The greatest recorded weight for this species is 10 kg (22 lb). The dorsal fin is divided in two parts, with four to seven spines in the front portion and 32 to 36 soft rays in the long, back portion. The anal fin has 26 to 30 soft rays.[2] The colour and pattern varies but it is typically dark brown with dark marbling on the upper body, paler on the lower body. The first dorsal fin has a dark spot in the membrane between each spine. The juveniles are yellowish or golden in colour during their benthic phase while the pelagic juveniles are silvery.[5]
Distribution
[edit]The marbled rockcod's range includes the northern end of the Antarctic Peninsula, the Scotia Arc, Prince Edward Islands, Crozet Islands, Kerguelen Islands, Heard Island and Macquarie Island, as well as the Ob Bank, and Lena Bank.[2]
Biology
[edit]Marbled rockcod females become sexually mature at about six years of age. Along with mature males they move into the deeper water of the continental shelf. Spawning takes place once a year and the young fish stay mostly in shallow water in the fiords and bays, feeding mainly on zooplankton. Males can live for up to twelve years.[2]
Fisheries
[edit]The marbled rockcod was heavily fished by Soviet fishers during the 1960s and 1970s, with catches exceeding 100,000 tonnes in some seasons; it almost disappeared from around South Georgia Island, and by 1980, was depleted throughout the Southern Ocean.[6] It took the population 20 years to show signs of recovery.[7]
References
[edit]- Tony Ayling & Geoffrey Cox, Collins Guide to the Sea Fishes of New Zealand, (William Collins Publishers Ltd, Auckland, New Zealand 1982) ISBN 0-00-216987-8
- ^ a b Bailly, Nicolas (2020). "Notothenia rossii Richardson, 1844". WoRMS. World Register of Marine Species. Retrieved 31 July 2020.
- ^ a b c d Froese, Rainer; Pauly, Daniel (eds.). "Notothenia rossii". FishBase. February 2014 version.
- ^ Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Species in the genus Notothenia". Catalog of Fishes. California Academy of Sciences. Retrieved 25 September 2021.
- ^ Christopher Scharpf & Kenneth J. Lazara, eds. (12 April 2021). "Order Perciformes: Suborder Notothenoididei: Families Bovichtidae, Pseaudaphritidae, Elegopinidae, Nototheniidae, Harpagiferidae, Artedidraconidae, Bathydraconidae, Channichthyidae and Percophidae". The ETYFish Project Fish Name Etymology Database. Christopher Scharpf and Kenneth J. Lazara. Retrieved 23 September 2021.
- ^ H.H. Dewitt; P.C. Heemstra; and O. Gon (1990). "Nototheniidae Notothens". In O. Gon and P.C. Heemstra (eds.). Fishes of the Southern Ocean. South African Institute for Aquatic Biodiversity. ISBN 9780868102115.
- ^ "Large-scale commercial marine harvesting". Lighthouse Foundation. Retrieved 23 July 2013.
- ^ Hollyman, Phillip; Hill, Simeon L.; Lapitkhovksy, Vladminir V.; et al. (2021). "A long road to recovery: dynamics and ecology of the marbled rockcod (Notothenia rossii) at South Georgia, 50 years after over-exploitation". ICES Journal of Marine Science. fsab150. doi:10.1093/icesjms/fsab150.