Genetic differentiation and structure of Chrysichthys nigrodigitatus populations in some Nigerian coastal waters

Abstract

The knowledge of genetic structure of a species is a key point for its effective conservation. On this note, studies were carried out to investigate the genetic differentiation and structure of Chrysichthys nigrodigitatus populations in some coastal rivers of Nigeria; Itu Bridge River, Badagry, Epe and Igbokoda. A total of 80 DNA samples from four river populations were analyzed at four microsatellite loci. Moderate interpopulation differentiation and sufficient genetic differentiation within individuals were indicated by the four microsatellite loci as evidenced by 3% variation among populations and 89% variation within individuals respectively by AMOVA analysis. This observation was further supported by limited gene flow found among populations. The populations exhibited a positive correlation between genetic and geographical distances which implies that the populations studied fit into isolation by distance model suggesting that structuring in C. nigrodigitatus populations is possibly due to isolation by distance.