A new species of characin from the Knodus genus has been described by a group of ichthyologists from Brazil.
Knodus geryi was described by Flavio Lima, Heraldo Britski and Francisco Machado in the latest issue of the journal Copeia. The description is based on specimens collected in the Rio do Piexe, a tributary of the Rio Cabacal in Brazil's Mato Gross region - the only known range of the fish at the moment.
The tetra was discovered during a Rapid Assessment Program (AquaRAP) expedition which took place in the Rio Paraguay's northern headwaters in Brazil. The colour pattern of the fish is so unique that the scientists instantly recognised it as an entirely new fish.
K. geryi has two distinct dark blotches on the caudal fin, as well as a number of unique morphological characters which set it apart from related characids.
The fish was found in a 2m deep, steep-sided 5-8m wide stretch of river containing rapids and waterfalls. Stomach analyses have shown that the new fish is primarily herbivorous.
For more details see the full paper: Lima, FCT., Britski, HA., Machado, FA (2004) - New Knodus (Ostariophysi: Characiformes: Characidae) from the Upper Rio Paraguay Basin, Brazil. Copeia 2004 (3) pp 577-582.