The bucktooth tetra (''Exodon paradoxus'') is the only member of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

''Exodon'' and is a

freshwater fish Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments differ from marine conditions in many ways, especially the difference in levels of s ...

of the

characin Characiformes is an order of ray-finned fish, comprising the characins and their allies. Grouped in 18 recognized families, more than 2000 different species are described, including the well-known piranha and tetras.; Buckup P.A.: "Relationsh ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

(family Characidae) of

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

Characiformes Characiformes is an order of ray-finned fish, comprising the characins and their allies. Grouped in 18 recognized families, more than 2000 different species are described, including the well-known piranha and tetras.; Buckup P.A.: "Relationshi ...

. It is native to the

Amazon Basin The Amazon basin is the part of South America drained by the Amazon River and its 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 of Boli ...

and Guyana. Though first described in 1845, it was not imported and distributed by the aquarium trade until 1932. This species has a typical elongated

tetra Terrestrial Trunked Radio (TETRA; formerly known as Trans-European Trunked Radio), a European standard for a trunked radio system, is a professional mobile radio and two-way transceiver specification. TETRA was specifically designed for use by ...

appearance; it is light tan in colour with two distinct black spots (one before the tail and another below the

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

). The dorsal fin is bright red. The appellation “bucktooth” does not describe the fish’s appearance, since Bucktooth tetras show no signs of having teeth. It grows to a maximum overall length of approximately 12 cm (4.7 in). The fish's natural diet consist of small

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s, other fish, and plants. It is not a safe tank mate for fellow

s, because it will eat small fish, nor is it a safe tank mate for larger species, because it is a notorious

lepidophage Lepidophagy is a specialised feeding behaviour in fish that involves eating the Scale (zoology), scales of other fish. Lepidophagy is widespread, having evolved independently in at least five freshwater families and seven marine families. A relat ...

. Bucktooth tetra are best kept alone or in large planted tanks that provide adequate protective coverage for other species. They are best kept in shoals of eight or more; a shoal of fewer than eight will pick at each other and stress the exodons to a point where it will either catch a disease or die of severe wounds. It is otherwise extremely hardy and can live in home aquaria for more than ten years.

References

* * Innes, W. T. ''Exotic Aquarium Fishes'', 19th ed. Innes Publishing Co. Philadelphia. 1956. Tetras Fish described in 1844 {{Characiformes-stub

See also

References