A new species of anostomine headstander has been described from Brazil.
Brian Sidlauskas of the University of Chicago and Geraldo Mendes dos Santos of Instituto Nacional de Pesquisas da Amazonia described the new headstander as Pseudanos winterbottomi in a paper in the journal Copeia.
The fish, which is a member of the family Anostomidae, was found in the Rio Orinoco drainage in Venezuela and in the Rio Tapajos drainage in Brazil.
It's said to resemble closely P. gracilis, and even shares almost identical meristic and morphological characters. However, rather than the row of lateral spots seen in gracilis, P. winterbottomi has just a single midlateral longitudinal stripe.
Although the name has not yet become widely used in the aquarium trade, this generic name is now the name for the commonly sold Three-spot headstander, formely Anostomus trimaculatus (now Pseudanos trimaculatus).
The genus contains three other species, besides this new one: P. gracilis, P. irinae and P. trimaculatus.
The authors have also produced an updated dichotomous key to the other genera in the Anostominae subfamily (Anostomus, Gnatholodolus, Pseudanos, Sartor and Synaptolaemus) to make it easier for other scientists to identify the anostomine species they're studying.
For more details on the new species see the paper: Sidlauskas, BL. and G. Mendes dos Santos (2005) - Pseudanos winterbottomi: a new anostomine species (TeleosteI: Characiformes: Anostomidae) from Venezuela and Brazil, and comments on its phylogenetic relationships. Copeia. Vol. 2005. No. 1. pp 109-123.