Phylogenetic Relationships of African Killifishes in the GeneraAphyosemionandFundulopanchaxInferred from Mitochondrial DNA Sequences

We have analyzed the phylogenetic relationships of 52 species representing all defined species groups (J. J. Scheel, 1990, Atlas of Killifishes of the Old World, 448 pp.) of the African aplocheiloid fish generaAphyosemionandFundulopanchaxin order to examine their interrelationships and to reveal trends of karyotypic evolution. The data set comprised 785 total nucleotides from the mitochondrial 12S rRNA and cytochromebgenes. The molecular-based topologies analyzed by both maximum parsimony and neighbor-joining support the monophyly of most previously defined species groups within these two killifish genera. The genusAphyosemionis monophyletic except for the nested position ofFundulopanchax kunzi(batesigroup; subgenusRaddaella) within this clade, suggesting that this taxon was improperly assigned toFundulopanchax.The remainingFundulopanchaxspecies sampled were supported as being monophyletic in most analyses. Relationships among the species groups in both genera were not as strongly supported, suggesting that further data will be required to resolve these relationships. Additional sampling from the 16S rRNA gene allowed further resolution of relationships withinFundulopanchax,more specifically identifying the nonannualscheeligroup as the basal lineage of this otherwise annual genus. Chromosomal evolution withinAphyosemionhas been episodic, with the evolution of a reducedn= 9–10 metacentric complement having occurred in multiple, independent lineages. Polarity of chromosomal reductions within theelegansspecies group appears to support previous hypotheses concerning mechanisms of karyotypic change within the genusAphyosemion.