Serpae tetra

The serpae tetra was first formally described as Chirodon eques in 1882 by the Austrian ichthyologist Franz Steindachner, with its type locality given as Villa Bella and Obidos on the Amazon River in Brazil. The genus name should have been spelt Cheirodon. This family is classified within the suborder Characoidei of the order Characiformes. ==Etymology==

The serpae tetra is classified in the genus Megalamphodus, which is Greek and means "with spacious ways", a name coined by Carl H. Eigenmann which he gave no explanation for. It may be an allusion to the "very large" fontanelles, the frontal bones being described as "entirely separate", that is, with a space between them and the parietal bones. The specific name, eques, means "horseman" or "rider", an allusion Steindachner did not explain but which may refer to the saddle-like mark on each side. Steindachner used this name for other fishes with similar markings. ==Description==

The serpae tetra has a maximum standard length of , and the body is laterally compressed and high. The overall colour is reddish-olive, brightening to scarlet along the flanks. There is a comma shaped black humeral spot and the dorsal fin is black, with the anal and caudal fins being red. ==Distribution and habitat==

The serpae tetra has a disjunct native range, with subpopulations in the Amazon basin of Brazil and in the La Plata basin in Argentina, Brazil, Bolivia, Paraguay and Uruguay. It has also been introduced to French Guiana and eastern Brazil. Its preferred habitat includes slow-flowing tributaries, floodplain lakes and associated flooded environments. It readily colonises anthropogenic aquatic habitats, such as artificial ponds and reservoirs. It is normally found close to submerged aquatic vegetation. ==Utilisation==

The serpae tetra is one of the most popular fishes in the aquarium trade, but almost all of the fishes traded are captive bred, and few are taken from the wild. ==See also==