Ruvettus pretiosus

Life-forms

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Megaclassis: Osteichthyes
Superclassis/Classis: Actinopterygii
Classis/Subclassis: Actinopteri
Subclassis/Infraclassis: Neopterygii
Infraclassis: Teleostei
Megacohors: Osteoglossocephalai
Supercohors: Clupeocephala
Cohors: Euteleosteomorpha
Subcohors: Neoteleostei
Infracohors: Eurypterygia
Sectio: Ctenosquamata
Subsectio: Acanthomorphata
Divisio/Superordo: Acanthopterygii
Subdivisio: Percomorphaceae
Series: Pelagiaria
Ordo: Scombriformes

Familia: Gempylidae
Genus: Ruvettus
Species: R. pretiosus

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 100 to 800 metres (330 to 2,620 ft), but most often between 200 and 400 metres (660 and 1,310 ft). Oilfish can grow to a length of 3 metres (9.8 ft), though most do not exceed 1.5 metres (4.9 ft). It is the only known member of its genus.[2][3]
Description

Oilfish are large, fusiform fish which often grow to 1.5 metres (4.9 ft) and a maximum of 3 metres (9.8 ft).[2] Other distinctive features of this fish include the large fangs, rough scales, two pairs of finlets, and a uniformly brown coloration.[3] 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.[4]
Habitat & 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.[2][3] If food is scarce on the seafloor, at night Oilfish will rise to the surface to prey on other fish, cephalopods, and crustaceans.[4][5]
Importance to Humans

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-inducing flesh, restaurants sell Oilfish meat under the name "white-fish" on account of its texture and flavor.[4][5]

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.[6]
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.[7] 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 9 charges of inappropriate labelling, and was fined HK$45,000.[8][9]

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.[10][11]

The Canadian Broadcasting Corporation in 2007 reported several cases in Canada where mislabelled Oilfish was sold at Chinese supermarkets.[12]
See also

Escolar, an Oilfish relative, also has high concentrations of wax esters and can be similarly mislabeled.

References

Collette, B.B.; Curtis, M.; Smith-Vaniz, W.F.; et al. (2015). "Ruvettus pretiosus". The IUCN Red List of Threatened Species. 2015: e.T190432A16644022. doi:10.2305/IUCN.UK.2015-4.RLTS.T190432A16644022.en.
Froese, Rainer; Pauly, Daniel (eds.) (2013). "Ruvettus pretiosus" in FishBase. April 2013 version.
Nakamura, I. and N.V. Parin, 1993. FAO Species Catalogue. Vol. 15. 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. FAO Fish. Synop. 125(15):136 p.
Vasilakopoulos P, Pavlidis M, Tserpes G. On the diet and reproduction of the oilfish Ruvettus pretiosus (Perciformes: Gempylidae) in the eastern Mediterranean. Journal of the Marine Biological Association of the United Kingdom. 2011;91(4):873-881. doi:10.1017/S0025315410001785
Viana, Danielle de Lima; Tolotti, Mariana Travassos; Porto, Mariana; Araújo, Rodolfo Jorge Vale de; Vaske Júnior, Teodoro; Hazin, Fabio Hissa Vieira (June 2012). "Diet of the oilfish Ruvettus pretiosus (Perciformes: Gempylidae) in the Saint Peter and Saint Paul archipelago, Brazil". Brazilian Journal of Oceanography. 60 (2): 181–188. doi:10.1590/S1679-87592012000200008. ISSN 1679-8759.
"Escolar and oilfish health warning" (PDF). Queensland Health. October 2011. Archived from the original (PDF) on March 29, 2012.
Kim, Caroline (January 31, 2007). "All parties in oilfish saga to face probe". The Standard. Hong Kong. Archived from the original on March 29, 2008.
"ParknShop admits selling oil fish as cod". South China Morning Post. 2007-11-20. Retrieved 2024-01-30.
"ParknShop fined over oilfish scandal". South China Morning Post. 2007-12-18. Retrieved 2024-01-30.
"Guidelines on identification and labelling of oilfish and cod issued". Hong Kong: Centre for Food Safety. August 16, 2007.
"Guidelines on Identification and Labelling of Oilfish/Cod" (PDF). Hong Kong: Centre for Food Safety.
"Canadians fall ill after eating mislabelled oily fish". CBC News. February 23, 2007. Archived from the original on October 23, 2012.