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Author: Miguel Vences

Abstract

Evidence is presented that golden-striped salamander Chioglossa lusitanica populations in eucalypt plantations may be subject to two influences. There is a low density of leaf litter invertebrates which are the preferred prey. Substrate choice experiments show that that the salamanders avoid eucalypt leaves as substrates for shelter. A long-term study of Chioglossa populations at two brooks in northern Portugal, however, showed that the numbers at one site did not change notably after plantation with eucalypts in comparison with the other, less altered, locality. Chioglossa is the most abundant amphibian species along water courses in the Spanish province of La Coruña, although eucalypts are planted along most of them.

In: Amphibia-Reptilia
In: Contributions to Zoology
In: Contributions to Zoology
Authors: Frank Glaw and Miguel Vences

Abstract

Advertisement calls of the Discoglossus-species D. pictus, D. sardus, D. galganoi, and D. montalentii were studied. In comparison with all other species, the advertisement call of D. montalentii is completely different. The frequency spectrum displays a harmonic structure and resembles a Bombina-call, while advertisement calls of the other Discoglossus species are mostly unharmonious. D. pictus auritus and D. pictus pictus show a great similarity of call patterns. D. galganoi is characterized by the longest call duration. The call of a red-backed Discoglossus with the vague locality "Sardinia", here named "D. spec.", differed substantially from the calls of D. sardus and any other studied specimen. The complex situation regarding the distribution of different Tyrrhenian Discoglossus phenotypes is discussed in this context.

In: Amphibia-Reptilia
Authors: Miguel Vences and Frank Glaw

Abstract

Advertisement calls of Discoglossus galganoi jeanneae from two localities in southern Spain and D. pictus scovazzi from Ceuta were analyzed. Call duration as well as ratio of pulse group intensities and durations clearly group D. pictus scovazzi with the other subspecies of D. pictus (pictus and auritus). The calls of the taxon jeanneae show some differences to calls of populations of D. g. galganoi from northern Spain, but are more similar to calls of D. g. galganoi than to those of D. pictus scovazzi. These data support the status of jeanneae as subspecies of galganoi.

In: Amphibia-Reptilia
Authors: Miguel Vences and Frank Glaw

Abstract

We describe a new frog species of the Mantidactylus boulengeri group (Amphibia: Anura: Mantellidae) in the subgenus Gephyromantis from south-eastern Madagascar. It is morphologically similar to M. eiselti and M. thelenae but differs in its advertisement calls with a distinctly shorter note duration, and in its bilobate (not single) subgular vocal sac. Like M. eiselti and M. thelenae the new species Mantidactylus enki is predominantly diurnal and calling males do not aggregate close to water bodies, indicating direct development as it has been demonstrated previously in M. eiselti. The advertisement calls of all three species are described in detail. A comparison with a further pair of cryptic species with bilobate vs. single subgular vocal sac (Mantidactylus tschenki — M. cornutus) did not reveal any consistent pattern of call variation correlated with vocal sac structure. Therefore, sexual selection may also be considered to explain differences in the colour and external structure of vocal sacs among closely related species.

In: Amphibia-Reptilia

Abstract

Age structure of populations of four species of endemic Malagasy frogs of the genus Mantella (M. aurantiaca, M. baroni, M. bernhardi, M. madagascariensis) was examined by skeletochronology based on 96 specimens from nine different localities. In more than half of these (57%), no lines of arrested growth (LAGs) were found, and the number of LAGs recognized in the remaining specimens was mostly one, and probably two in three specimens. It is generally considered that each LAG corresponds to one year of life; our results therefore confirm that in Mantella populations almost all specimens are in their first or second year of life.

In: Amphibia-Reptilia

We describe the tadpoles of three species of Malagasy frogs, classified in the genus Spinomantis, based on specimens identified by DNA barcoding. The tadpole of Spinomantis aglavei is a typical Orton type IV larva. The oral disc is not emarginated laterally, but has two mid-ventral folds and a labial tooth row formula of 3(2- 3)/2(1). The tadpole of S. phantasticus is similar, the oral disc being laterally emarginated and having one medial fold; LTRF is 3/3(1). A third species, S. cf. fimbriatus is also similar to the other two species; the oral disc is not laterally emarginated but has three medial folds and LTRF is 3(2-3)/3(1). One shared character is a median fold or emargination in the lower part of the oral disc, although the shape of this fold is different in each of the three species. Only single specimens were available for examination in S. aglavei and S. phantasticus , preventing a further discussion of intraspecific morphological variation and of possibly diagnostic characters of larval morphology.

In: Contributions to Zoology