Oilfish

{{Short description|Species of fish}} {{about||the Baikal Oilfish|Comephorus|fish that contain oils|Oily fish}} {{Speciesbox | name = Oilfish | image = Oilfish.jpg | image2 = Ruvettus pretiosus (oilfish).png | status = LC | status_system = IUCN3.1 | status_ref = <ref name = IUCN>{{cite iucn| author1 = Collette, B.B. |author2 = Curtis, M. | author3 = Smith-Vaniz, W.F.| author4 = Pina Amargos, F. | author5 = Williams, J.T. | author6 = Grijalba Bendeck, L. | name-list-style= amp | year = 2015 | title = ''Ruvettus pretiosus'' | article-number = e.T190432A16644022 |doi = 10.2305/IUCN.UK.2015-4.RLTS.T190432A16644022.en | access-date = 1 September 2024}}</ref> | genus = Ruvettus | parent_authority = Cocco, 1833 | species = pretiosus | authority = Cocco, 1833 | synonyms = {{collapsible list|bullets = true | ''Rovetus temminckii'' Cantraine, 1833 | ''Tetragonurus simplex'' R. T. Lowe, 1839 | ''Thyrsites acanthoderma'' R. T. Lowe, 1839 | ''Thyrsites scholaris'' Poey, 1854 | ''Ruvettus tydemani'' M. C. W. Weber, 1913 | ''Ruvettus pacificus'' D. S. Jordan & E. K. Jordan, 1922 | ''Ruvettus delagoensis'' Gilchrist & von Bonde, 1924 | ''Ruvettus whakari'' Griffin, 1927 }} }} [[File:Ruvettus pretiosus Oilfish Natural.jpg|thumb|An oilfish 1000–3000 meters deep at Johnston Atoll]] '''Oilfish''' ('''''Ruvettus pretiosus''''') are a species of snake mackerel with a cosmopolitan distribution in tropical and temperate oceans. They can be found at depths from {{convert|100|to|800|m|ft}}, but most often between {{convert|200|and|400|m|ft}}. Oilfish can grow to a length of {{convert|3|m|ft}}, though most do not exceed {{convert|1.5|m|ft}}. It is the only known member of its genus.<ref name=":0">{{FishBase |genus= Ruvettus|species= pretiosus| month = April | year = 2013}}</ref><ref name=":1">{{cite book|author=Nakamura, I. |author2=N.V. Parin|year=1993 |title= Snake mackerels and cutlassfishes of the world (families Gempylidae and Trichiuridae). An annotated and illustrated catalogue of the snake mackerels, snoeks, escolars, gemfishes, sackfishes, domine, oilfish, cutlassfishes, scabbardfishes, hairtails, and frostfishes known to date|series=FAO Species Catalogue|volume=15|publisher=Food and Agriculture Organisation of the United Nations|url=https://www.fao.org/fishery/en/publications/42908|isbn=92-5-103124-X}}</ref>

== Description == Oilfish are large, fusiform fish which often grow to {{convert|1.5|m|ft}} and a maximum of {{convert|3|m|ft}}.<ref name=":0" /> Other distinctive features of this fish include the large fangs, rough scales, two pairs of finlets, and a uniformly brown coloration.<ref name=":1" /> Oilfish meat is extremely oily, containing high lipid concentrations. Though edible, the oil mainly consists of wax esters, which makes the meat act as a laxative if consumed in large quantities.<ref name=":2">{{cite journal|author=Vasilakopoulos P|author2= Pavlidis M|author3= Tserpes G. |title=On the diet and reproduction of the oilfish ''Ruvettus pretiosus'' (Perciformes: Gempylidae) in the eastern Mediterranean|journal=Journal of the Marine Biological Association of the United Kingdom|year=2011|volume=91|issue=4|pages=873-881 |doi=10.1017/S0025315410001785}}</ref>

== Habitat and ecology == Oilfish are distributed throughout tropical and temperate waters across the world, being recorded in the Atlantic, Indian, and Pacific oceans, including the Mediterranean Sea. They are found in the deep water benthic environments of continental slopes and seamounts, where they group in pairs or remain solitary.<ref name=":0" /><ref name=":1" /> If food is scarce on the seafloor, at night oilfish will rise to the surface to prey on other fish, cephalopods, and crustaceans.<ref name=":2" /><ref name=":3">{{Cite journal |last=Viana |first=Danielle de Lima |last2=Tolotti |first2=Mariana Travassos |last3=Porto |first3=Mariana |last4=Araújo |first4=Rodolfo Jorge Vale de |last5=Vaske Júnior |first5=Teodoro |last6=Hazin |first6=Fabio Hissa Vieira |date=June 2012 |title=Diet of the oilfish Ruvettus pretiosus (Perciformes: Gempylidae) in the Saint Peter and Saint Paul archipelago, Brazil |url=http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592012000200008&lng=en&tlng=en |journal=Brazilian Journal of Oceanography |volume=60 |issue=2 |pages=181–188 |doi=10.1590/S1679-87592012000200008 |issn=1679-8759|doi-access=free }}</ref>

== Human use == Fisheries targeting oilfish are rare, occurring in small regions of the Atlantic and Pacific through the use of handlines. However, oilfish are common bycatch for fisheries targeting tuna and swordfish, which employ longlines. Despite their laxative flesh, restaurants sell oilfish meat under the name "white-fish" on account of its texture and flavor.<ref name=":2" /><ref name=":3" />

The flesh of oilfish is rich in taste and can be substantially cheaper than that of other fish species, leading to some vendors intentionally mislabelling it as butterfish or cod. The consumer may then eat larger servings than recommended, unaware of the laxative effect, and suffer from diarrhea.<ref>{{Cite web |date=October 2011 |title=Escolar and oilfish health warning |url=http://www.health.qld.gov.au/foodsafety/documents/fs-9-oilfish.pdf |archive-url=https://web.archive.org/web/20120329055046/http://www.health.qld.gov.au/foodsafety/documents/fs-9-oilfish.pdf |archive-date=March 29, 2012 |publisher=Queensland Health}}</ref>

In Cabo Verde, oilfish is occasionally caught and sold to fishmongers at port, who trade among each other or sell to consumers who request it. While rarely sold at market due to its laxative effects, oilfish is well known among fishmongers and fishermen, and goes by the name ''xoba'' in Praia and Cagazeite, which means "shit out oil" in São Vicente.

=== ParknShop oilfish incident === In January 2007, ParknShop, a supermarket chain in Hong Kong, admitted to selling mislabeled oilfish in their stores. Over 600 people became sick as a result, suffering from stomach pain and diarrhea. A total of 14 complaints were filed against the supermarket chain, leading to an investigation by the Centre for Food Safety. The fish were originally mislabeled in Indonesia, leading to an investigation and allegations of corruption.<ref>{{cite web |last=Kim |first=Caroline |date=January 31, 2007 |title=All parties in oilfish saga to face probe |url=http://www.thestandard.com.hk/news_detail.asp?pp_cat=11&art_id=37251&sid=11970701&con_type=1&d_str=20070131&sear_year=2007 |archive-url=https://web.archive.org/web/20080329015603/http://www.thestandard.com.hk/news_detail.asp?pp_cat=11&art_id=37251&sid=11970701&con_type=1&d_str=20070131&sear_year=2007 |archive-date=March 29, 2008 |website=The Standard |location=Hong Kong}}</ref> ParknShop stopped selling the fish, but argued in court that there was no law against the sale of oilfish. The supermarket would later plead guilty to nine charges of inappropriate labelling, and was fined HK$45,000.<ref>{{Cite web |date=2007-11-20 |title=ParknShop admits selling oil fish as cod |url=https://www.scmp.com/article/616310/parknshop-admits-selling-oil-fish-cod |access-date=2024-01-30 |website=South China Morning Post |language=en}}</ref><ref>{{Cite web |date=2007-12-18 |title=ParknShop fined over oilfish scandal |url=https://www.scmp.com/article/620011/parknshop-fined-over-oilfish-scandal |access-date=2024-01-30 |website=South China Morning Post |language=en}}</ref>

As a result of the incident, the Centre for Food Safety in Hong Kong published new guidelines on the proper labelling of oilfish and escolar to consumers, preventing mislabeling.<ref>{{Cite web|url=http://www.cfs.gov.hk/english/press/2007_08_16_1_e.html|title=Guidelines on identification and labelling of oilfish and cod issued|date=August 16, 2007|publisher=Centre for Food Safety|location=Hong Kong|access-date=August 29, 2008|archive-date=October 16, 2008|archive-url=https://web.archive.org/web/20081016091409/http://www.cfs.gov.hk/english/press/2007_08_16_1_e.html|url-status=dead}}</ref><ref>{{Cite web|url=http://www.cfs.gov.hk/tc_chi/food_leg/files/oil_fish_guideline_070723.pdf|title=Guidelines on Identification and Labelling of Oilfish/Cod|publisher=Centre for Food Safety|location=Hong Kong}}</ref>

The Canadian Broadcasting Corporation in 2007 reported several cases in Canada where mislabelled oilfish was sold at Chinese supermarkets.<ref>{{Cite news|url=https://www.cbc.ca/news/science/canadians-fall-ill-after-eating-mislabelled-oily-fish-1.649068|archive-url=https://web.archive.org/web/20121023070921/http://www.cbc.ca/news/story/2007/02/23/oilfish.html|archive-date=October 23, 2012|title=Canadians fall ill after eating mislabelled oily fish|date=February 23, 2007|url-status=live|website=CBC News}}</ref>

==See also== *Escolar, an oilfish relative, also has high concentrations of wax esters and can be similarly mislabeled.

==References== {{Reflist|30em}}

Category:Gempylidae Category:Cosmopolitan fish Category:Taxa named by Anastasio Cocco Category:Fish described in 1833