Genetic Similarity Amongst Phenotypically Diverse Little Free-Tailed Bats,Chaerephon pumilus

Abstract

The African molossid Chaerephon pumilus shows extensive variation in colour, size and echolocation across its wide distributional range with a light-winged form in north-eastern Africa and a dark form in southern Africa. There is also much variation in supposedly diagnostic characters (e.g., degree of palatial emargination) amongst the dark form of this species in southern Africa. These differences suggest that there may be cryptic species within C. pumilus. We used phylogenetic and phenetic analyses of sequence data from the mitochondrial cytochrome-b gene of a number of C. pumilus individuals to investigate the status of the light and dark-winged forms of this species and to evaluate the possibility of cryptic species within the dark-winged form of C. pumilus in southern Africa. We evaluated species status by comparing the level of sequence divergence amongst C. pumilus with the level of sequence divergence between known species in the genus. These included C. ansorgei, C. chapini, C. nigeriae and C. jobensis. Intrageneric sequence divergences among the Chaerephon spp. included here ranged from 6.51 to 11.18%, whereas the average sequence divergence between the light and dark forms was 0.9%. This suggests that these two forms are not distinct species. Individuals of the dark form of C. pumilus were genetically indistinguishable from each other having the same cytochrome b haplotype. We thus found no evidence of cryptic species in southern African C. pumilus.