Morphological characterization, cytogenetic analysis, and geographical distribution of the Pygmy Marbled Newt Triturus marmoratus pygmaeus (Wolterstorff, 1905) (Caudata: Salamandridae)

Triturus marmoratus pygmaeus, a problematic subspecies of the Marbled Newt from the southern part of the Iberian Peninsula, is redescribed using specimens collected in the “typical” area. Diagnostic external morphological features are provided to permit the accurate determination of the specimens belonging either to T. m. marmoratus or to T. m. pygmaeus. These diagnostic features were applied to individuals both from the field and from museum collections. The results indicate a larger distributional area for T. m. pygmaeus than was previously recognized. The distribution of T. m. marmoratus ranges over the northern half of the Iberian Peninsula and most of France; T. m. pygmaeus occupies the southwestern part of the Iberian Peninsula. The contact area between the two subspecies seems to be located along the Central Range Mountains (Sistema Central) in Portugal and Spain. T. m. marmoratus extends southwards beyond this borderline in three areas: Serra da Estrela (Portugal), Sierra de Gata (Spain) and Sierra de Guadarrama (Spain). The only point at which T. m. pygmaeus reaches northwards beyond the Central System is near Puerto de Malagón (Madrid Province, Spain). No cases of strict sympatry, nor individuals with intermediate morphological features have been observed. The results of an extensive cytogenetical analysis do not show any differences between T. m. pygmaeus and T. m. marmoratus. Interestingly, however, the T. m. pygmaeus populations from Doñana (Huelva Province, Spain) showed an exclusive, though little differentiated, C-banding pattern.