Comparative chromosome morphology of Malagasy poison frogs (Amphibia: Ranidae: Mantella)

Karyotypes of 7 species of Mantella are described, and are used to draw hypotheses on interspecific relationships. All studied species, M. betsileo, M. viridis, M. laevigata, M. haraldmeieri, M. baroni, M. crocea and M. aurantiaca, had a chromosome complement of 2n = 26, with 5 pairs of large chromosomes and 8 pairs of small chromosomes. We performed phenetic analysis of relative chromosome lengths (rl) and centromer indices (ci) as well as phylogenetic analysis of c-banding patterns and some distinct rl: and ci differences. All results indicated close relationships of M. aurantiaca and M. crocea. By phenetic analysis, M. betsileo and M. viridis are closely grouped together, as are M. laevigata and M. baroni. By phylogenetic analysis, M. haraldmeieri, M. betsileo and M. viridis are the most basal species, whereas M. laevigata and M. baroni sequentially split off from a clade leading to M. aurantiaca and M. crocea. These results are largely in agreement with other data sets. However, the position of M. laevigata, which is difficult to assess due to its large number of autapomorphies, and of M. haraldmeieri, are partially conflicting with results from osteology, bioacoustics, colouration and allozyme differentiation.