''Cetopsis coecutiens'', the ''candiru-açú'', ''piracatinga'', ''bagre ciego'' ( lit. blind catfish), or the blue whale catfish, is a species of catfish found throughout the

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

and

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

. The fish was first described by

Hinrich Lichtenstein Martin H nrich Carl Lichtenstein (10 January 1780 – 2 September 1857) was a German physician, List of explorers, explorer, botanist and zoologist. He explored parts of southern Africa and collected natural history specimens extensively and ...

in 1819, who named it for its resemblance to certain cetaceans. ''C. coecutiens'' is one of the largest species of "candiru" catfish. While these catfish are reported to grow to a size of , some specimens greater than have been caught in the wild. ''Cetopsis coecutiens'', like its

sister A sister is a woman or a girl who shares parents or a parent with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to ref ...

species '' C. candiru'', is a carnivorous fish and commonly described as a voracious feeder, making use of powerful jaw musculature and a nearly continuous cutting surface of the incisiform dentition. The distributions of both species overlap and both ''Cetopisis'' species are known to simultaneously feed on the same

bodies Bodies may refer to: Literature * ''Bodies'' (comics), a 2014–2015 Vertigo Comics detective fiction series * ''Bodies'' (novel), a 2002 novel by Jed Mercurio * ''Bodies'', a 1977 play by James Saunders * ''Bodies'', a 2009 book by Susie Orba ...

. They do however differ in the specifics of their behavior. ''Cetopsis candiru'' typically bite into carcasses and twist to create an entry into the body before proceeding to feed from the inside, where they may congregate in vast numbers during feeding frenzies. Due to these habits carcasses that were fed on by ''C. candiru'' oftentimes appear almost entirely skeletonized, but retain

cartilage Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...

eyeball An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the eye ...

s and tight skin. ''Cetopsis coecutiens'' on the other hand does not remain inside the body and instead will return to it multiple times, each time ripping away chunks of flesh. Both species leave similar circular bitemarks on bodies they scavenged on. They are opportunistic animals, feeding on the carcasses of animals that have drowned or otherwise died and fallen into the water. The role of these fish as important aquatic

scavenger Scavengers are animals that consume Corpse decomposition, dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a he ...

s is highlighted by their prominent appearance in

forensics Forensic science combines principles of law and science to investigate criminal activity. Through crime scene investigations and laboratory analysis, forensic scientists are able to link suspects to evidence. An example is determining the time and ...

around the Amazon, being well known to even feed on

cadaver A cadaver, often known as a corpse, is a Death, dead human body. Cadavers are used by medical students, physicians and other scientists to study anatomy, identify disease sites, determine causes of death, and provide tissue (biology), tissue to ...

s found in the various rivers of northern South America. At least one confirmed report tells of a single ''Cetopsis'' attacking a living child, although the exact culprit could not be determined between the two carnivorous species ''C. candiru'' and ''C. coecutiens''. Other reports mention ''Cetopsis candiru'' feeding on live fish caught in

gillnets Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is ...

or hooked by fishermen. ''C. coecutiens'' is occasionally kept in aquariums. The fish will accept frozen food and readily eats

live food Live food is living animals used as food for other carnivorous or omnivorous animals kept in captivity; in other words, small preys (such as insects, small fish or rodents) fed alive to larger predators kept either in a zoo or as a pet. Live ...

. A sparsely lit tank is recommended to more closely mimic the fish's natural habitat.

References

{{Taxonbar, from=Q5624230 Cetopsidae