The wimple piranha, (''Catoprion mento''), is a specialized, South American

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

piranha A piranha (, or ; ) is any of a number of freshwater fish species in the subfamily Serrasalminae, of the family Serrasalmidae, in the order Characiformes. These fish inhabit South American rivers, floodplains, lakes and reservoirs. Although ...

that feeds on fish scales. There is some debate over whether or not this species is considered a true piranha. If considered a true piranha, it would be the smallest species of piranha in the world.

Taxonomy

The wimple piranha is not traditionally considered to be a true piranha; the shape of its teeth and the presence of two rows of teeth (instead of one) on the upper jaw makes it different from the other piranha genera. However, through

molecular analysis Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...

, this species should be included in the true piranha group if the piranha group is to be

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

(see

for further discussion).

Distribution and habitat

The wimple piranha is found in the

Amazon Amazon most often refers to: * Amazon River, in South America * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon (company), an American multinational technology company * Amazons, a tribe of female warriors in Greek myth ...

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

, Essequibo, and upper

Paraguay River The Paraguay River (''Ysyry Paraguái'' in Guarani language, Guarani, ''Rio Paraguai'' in Portuguese language, Portuguese, ''Río Paraguay'' in Spanish language, Spanish) is a major river in south-central South America, running through Brazil, Bol ...

basins in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. This species inhabits clear freshwater streams and lakes with abundant submerged vegetation.

Description

The wimple piranha reaches about 15 cm (6.5 in) in

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

. The curve of its large,

banana A banana is an elongated, edible fruit – botanically a berry – produced by several kinds of large treelike herbaceous flowering plants in the genus '' Musa''. In some countries, cooking bananas are called plantains, distinguishing the ...

-shaped lower jaw creates a distinctive protuberance; this gave this fish the specific name ''mento'', which means 'chin'. Its reduced, conical teeth on the upper jaw project forward when the jaws are closed. The wimple piranha has 62

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

s, which is more than average for related fishes (60 chromosomes).

Ecology

This fish possesses powerful dentition and can inflict serious bites. The dietary breadth of the wimple piranha is one of the narrowest reported for fishes; scales form an important proportion of the diet throughout most of its life, and adults feed almost entirely on them (see

lepidophagy Lepidophagy is a specialised feeding behaviour in fish that involves eating the scales of other fish. Lepidophagy is widespread, having evolved independently in at least five freshwater families and seven marine families. A related feeding behavior ...

). In laboratory conditions, wimple piranhas are known to feed on scales from fish up to three times their own length, and are even known to feed on scales of conspecifics. Like most fish, when the wimple piranha feeds on small fish or scales floating in the water, it uses suction feeding. However, to feed on scales attached to fish, it uses ram feeding, where the predator will charge at the fish; the force of this collision actually knocks scales free. The teeth are used to scrape scales from the body. Scales are ingested both during the strike and after, when loose scales are also eaten. These attacks remove only scales without damaging the underlying musculature.

References

{{Taxonbar, from=Q2298006 Catoprion Piranhas Freshwater fish of Brazil Freshwater fish of Colombia Fish described in 1819 Taxa named by Georges Cuvier