Key to Species of Pachypops

1 Brown spots present on sides of body, body depth 4.3 or more in SL......................................................... Pachypops pigmaeus n. sp. (Rio Machado and Madeira basins and upper Rio Branco, Brazil)

­ Spots absent on sides of body, body depth less than 4.1 in SL................ 2

2 Dark longitudinal stripes present on sides of body, horizontal eye diameter from 3.0 to 3.7 in HL..... Pachypops trifilis (Rivers of Guyana and Rio Amazonas basin)

­ Longitudinal stripes absent on sides of body, horizontal eye diameter from 2.4 to 3.1 into HL............................................ Pachypops fourcroi (Amazonas, Essequibo, Corantijn, Approuague and Orinoco basins)