Effects of turbidity on the neural structures of two closely related redfin minnows, Pseudobarbus afer and P. asper, in the Gamtoos River System, South Africa

Abstract

The neural structures of the sister species Pseudobarbus afer and P. asper were compared. P. afer, a redfin minnow which inhabits clear, perennial mountain streams, was found to have larger neural structures related to vision than P. asper, which inhabits turbid, intermittent streams of the Gamtoos River system, P. asperdid not show any compensation to inhabiting a turbid environment. Overall, P. afer males had the largest neural structures, most notably the optic lobes and cerebella, and P. asper females had the smallest neural structures.