The bucktooth tetra (''Exodon paradoxus'') is the only member of the genus ''Exodon'' and is a freshwater fish 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.: "Relationshi ...

family (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 d ...

Characiformes. 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 Bolivi ...

and

Guyana Guyana ( or ), officially the Cooperative Republic of Guyana, is a country on the northern mainland of South America. Guyana is an indigenous word which means "Land of Many Waters". The capital city is Georgetown. Guyana is bordered by the ...

. Though first described in 1845, it was not imported and distributed by the aquarium trade until 1932. This species has a typical elongated tetra appearance; it is light tan in colour with two distinct black spots (one before the tail and another below the dorsal fin). 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 invertebrates, other fish, and plants. It is not a safe tank mate for fellow tetras, 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