Taxonomic status and genetic differentiation among West African populations of theChrysichthys auratuscomplex (Pisces, Siluriforme), based on protein electrophoresis

摘要

Abstract.Thirteen populations ofChrysichthys auratus longifilis(Pfaff) andC. filamentosus(Boulenger) from five West African drainages were studied using enzymatic protein electrophoresis to estimate genetic differentiation and verify their taxonomic status. Twenty seven alleles were observed at 19 loci. Only five loci were polymorphic. Genetic distance and cladistical analyses based on presences/absences of alleles did not separate the populations in groups corresponding to the two taxa. The maximum genetic distances between two populations (D= 0·112) is lower than the level of maximum divergence observed between conspecific populations of species of the genus in other studies using the same enzymatic systems (D = 0·289 inC. maurus; D = 0·304 inC nigrodigitatus). These results confirm those of Risch (1986a) who, using morphological data, considered the two taxa to be synonyms. Genetic variability in several of these populations is also low (0·00