New distributional data and genetic variation of Panaspis breviceps (Squamata: Scincidae) indicate a biogeographic connection across the Congo Basin

Abstract

In the central Congolian lowland forests we discovered for the first time Panaspis breviceps, a rarely found scincid lizard from the Central African riparian forests. Given that the Central African forests exhibit heterogeneity in the distribution of environmental characteristics and forms distinct ecoregions, the question arises as to how this newly discovered population compares with other populations in Central Africa and particularly in the Congolian lowland forests. We reviewed the distribution records of this species and examined and compared new and available genetic data (mitochondrial DNA). Maximum likelihood phylogenetic analysis revealed the existence of two evolutionary lineages differing by 2.0% in 16S rRNA. One lineage occurs in and around the southern Cameroon Highlands, but its distribution southwards is poorly documented. The other lineage includes the western, central and eastern populations of the Congo Basin, suggesting certain biogeographic connectivity across the Congolian forests. These results support the hypothesis of limited biogeographic barriers to the distribution of lizards in the Congolian lowland forests, but this remains to be tested using additional independent markers, denser sampling and multiple species.