Morphometric variation and divergence in the West Mediterranean Discoglossus (Amphibia: Discoglossidae)

Morphometrics of the four species of the genus Discoglossus occurring in the West Mediterranean area D. galganoi, D. montalentii, D. pictus and D. sardus ) was investigated. Univariate and multivariate statistics showed that the species are morphologically diverse and that populations of the same species form distinct and recognizable groups. Our results conflict in part with those derived from allozyme analysis of the same taxa. The major conflict involves the comparisons between D. montalentii and D. sardus , and between D. g. galganoi and D. g. jeanneae. . Whereas D. montalentii is genetically very distinct from D. sardus , their morphometric diversity is relatively low. On the other hand, morphometric divergence between D. g. galganoi and D. g. jeanneae (the latter described as a species by Busack, i.e. D. jeanneae , is high, but they are very similar genetically. Both adaptation to the different climatic regimes characterizing the West Mediterranean area and the phylogenetic history are suggested to account for the observed changes in the morphology.