Lycodichthys is a genus of marine ray-finned fish belonging to the family Zoarcidae, the eelpouts. They are found in the Southern Ocean.
| Lycodichthys | |
|---|---|
| |
| Lycodichthys antarcticus | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Scorpaeniformes |
| Family: | Zoarcidae |
| Subfamily: | Lycodinae |
| Genus: | Lycodichthys Paul Pappenheim, 1911[1] |
| Type species | |
| Lycodichthys antarcticus Pappenheim, 1911[2]
| |
| Synonyms[3] | |
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Taxonomy
editLycodichthys was first proposed as a monospecific genus in 1911 by the German zoologist Paul Pappenheim when he described L. antarcticus giving its type locality as the Gauss winter station on the coast of Kaiser Wilhelm II Land in Antarctica.[2][4] The American ichthyologist Hugh Hamilton DeWitt described Rhigophila dearbornii in 1962 but in 1988 this taxon was reviewed by the South African based American ichthyologist M. Eric Anderson and reclassified as the second species in Lycodichthys, making Rhigophila as synonym of Lycodichthys.[5] This genus is classified in the subfamily Lycodinae, one of four subfamilies in the family Zoarcidae, the eelpouts.[6]
Etymology
editLycodichthys combines the name of the Northern genus Lycodes with ichthys, meaning "fish", as this genus closely resembles Lycodes in the shape of the body and fins.[7]
Species
editLycodichthys contains the following species:[8]
- Lycodichthys antarcticus Pappenheim, 1911
- Lycodichthys dearborni (DeWitt, 1962)
Characteristics
editLycodichthys eelpouts have robust bodies which have a depth which is equal to 8.4% to 12.7% of their standard length. They have firm, thick skin and both scales and the lateral line are present. Pelvic fins can be either present or absent. There are five suborbital bones and five pores on the head. The gill slit does not typically extend as far as the lower edge of the base of the pectoral fin. There are no vomerine or palatine teeth.[5] Both species within Lycodichthys are similar in size with maximum published of 24 cm (9.4 in) for L. antarcticus and 23 cm (9.1 in) for L. dearbornii.[8]
The evolution of the antifreeze protein in L. dearborni provides a prime example of neofunctionalization after gene duplication. In the case of the Antarctic zoarcid fish type III antifreeze protein gene (AFPIII; P12102) diverged from a paralogous copy of sialic acid synthase (SAS) gene.[9] The ancestral SAS gene was found to have both sialic acid synthase and rudimentary ice-binding functionalities. After duplication one of the paralogs began to accumulate mutations that led to the replacement of SAS domains of the gene allowing for further development and optimization of the antifreeze functionality.[9] The new gene is now capable of noncolligative freezing-point depression, and thus is neofunctionalized.[9] This specialization allows Antarctic zoarcid fish to survive in the frigid temperatures of the Antarctic Seas.
Distribution and habitat
editLycodichthys are endemic to the waters of the Southern Ocean off Antarctica, L. antarcticus occurs from the northern tip of the Antarctic Peninsula east as far as Wilkes Land being found at depths between 195 and 540 m (640 and 1,772 ft) while L. dearborni has only been recorded from the Ross Sea at depths between 550 and 588 m (1,804 and 1,929 ft),[5]
References
edit- ^ Bisby F.A., Roskov Y.R., Orrell T.M., Nicolson D., Paglinawan L.E., Bailly N., Kirk P.M., Bourgoin T., Baillargeon G., Ouvrard D. (red.) (2011). "Species 2000 & ITIS Catalogue of Life: 2011 Annual Checklist". Species 2000: Reading, UK. Retrieved 24 September 2012.
{{cite web}}: CS1 maint: multiple names: authors list (link) - ^ a b Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Genera in the family Lycodinae". Catalog of Fishes. California Academy of Sciences. Retrieved 9 November 2022.
- ^ "Lycodichthys". WoRMS. World Register of Marine Species. Retrieved 11 November 2022.
- ^ Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Species in the genus Lycodichthys". Catalog of Fishes. California Academy of Sciences. Retrieved 11 November 2022.
- ^ a b c M. Eric Anderson (1994). "Systematics and Osteology of the Zoarcidae (Teleostei: Perciformes)". Ichthyological Bulletin of the J.L.B. Smith Institute of Ichthyology. 60.
- ^ Anderson , M. E. and V. V . Fedorov (2004). "Family Zoarcidae Swainson 1839 — eelpouts" (PDF). California Academy of Sciences Annotated Checklists of Fishes. 34.
- ^ Christopher Scharpf & Kenneth J. Lazara, eds. (6 May 2022). "Order Perciformes Suborder Cottoidea: Infraorder Zoarcales: Family: Zoarcidae". The ETYFish Project Fish Name Etymology Database. Christopher Scharpf and Kenneth J. Lazara. Retrieved 11 November 2022.
- ^ a b Froese, Rainer; Pauly, Daniel (eds.). "Species in genus Lycodichthys". FishBase. June 2022 version.
- ^ a b c Deng C, Cheng CH, Ye H, He X, Chen L (December 2010). "Evolution of an antifreeze protein by neofunctionalization under escape from adaptive conflict". Proceedings of the National Academy of Sciences of the United States of America. 107 (50): 21593–8. Bibcode:2010PNAS..10721593D. doi:10.1073/pnas.1007883107. PMC 3003108. PMID 21115821.