Inhaltszusammenfassung

Three character complexes (osteological features, nuptial pad morphology and integument structure) were studied in seven Central Peruvian Telmatobiinae, Batrachophrynus brachydactylus, B. macrostomus, Telmatobius carrillae, T. hockingi, T. jelskii, T. mayoloi and T. rimac, and in Alsodes montanus which originates from Chile and was used for outgroup comparisons. Skull features often varied stronger between conspecific specimens than between species, and the extension of humeral crests differe...Three character complexes (osteological features, nuptial pad morphology and integument structure) were studied in seven Central Peruvian Telmatobiinae, Batrachophrynus brachydactylus, B. macrostomus, Telmatobius carrillae, T. hockingi, T. jelskii, T. mayoloi and T. rimac, and in Alsodes montanus which originates from Chile and was used for outgroup comparisons. Skull features often varied stronger between conspecific specimens than between species, and the extension of humeral crests differed between the sexes. There were no clear-cut osteological differences among the genera, and not only Batrachophrynus but also T. carrillae lacked maxillary and vomerine teeth. Palmar morphology, specifically the type and numbers of spicules on the nuptial excrescences, provided species-specific characters and distinguished Batrachophrynus (spicules absent or unkeratinized) from Telmatobius and Alsodes (spicules keratinized). Skin texture and cutaneous gland histochemistry showed also taxonspecific features that allowed to identify B. macrostomus, T. hockingi and A. montanus at the level of specimens. All Central Peruvian taxa possessed serous glands with small granules (type I), but B. brachydactylus, B. macrostomus and T. carrillae lacked serous glands with large granules (type II) which were present in the other four Telmatobius. The absence of type I serous glands in Alsodes montanus and the small size of type II glands, deviating from those found in Telmatobius, corroborate its position as outgroup. Phylogenetic analysis of the three character complexes clearly supports monophyly of Batrachophrynus and places T. carrillae closer to Batrachophrynus than to any Telmatobius. Outgroup comparison suggests that several distinctive characters of Batrachophrynus (dentition, unkeratinized nuptial pad, absence of type II glands) are most probably derived states (secondary reductions) rather than ancestral ones. If so, and considering that T. mayoloi (type II glands rare and not present in all individuals) and even more T. carrillae (edentate, type II glands absent) show similar reductive tendencies, Batrachophrynus seems to be recently derived from the Telmatobius stock. In this case, graded reductions would connect the primitive Central Peruvian Telmatobiinae (T. hockingi, T. jelskii, T. rimac) over T. mayoloi and T. carrillae to B. brachydactylus and to the most derived B. macrostomus. Although there is no doubt about the sister species relationship between the last two species, their degree of differentiation from Telmatobius may be too low to require an own generic status. Information on more species and on additional character complexes (e.g. karyological features, DNA sequences) and thus, a better understanding of the evolutionary processes within this peculiar group would surely help to settle the controversy on the validity of Batrachophrynus.» weiterlesen» einklappen

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Klassifikation

DFG Fachgebiet:
Zoologie

DDC Sachgruppe:
Tiere (Zoologie)