Mantella

About: Mantella is a research topic. Over the lifetime, 92 publications have been published within this topic receiving 2575 citations.

Skeletochronological analysis of age structure in populations of four species of Malagasy poisonous frogs, genus Mantella

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.

Phenotypic and genetic diversity in aposematic Malagasy poison frogs (genus Mantella).

Abstract: Intraspecific color variation has long fascinated evolutionary biologists. In species with bright warning coloration, phenotypic diversity is particularly compelling because many factors, including natural and sexual selection, contribute to intraspecific variation. To better understand the causes of dramatic phenotypic variation in Malagasy poison frogs, we quantified genetic structure and color and pattern variation across three closely related species, Mantella aurantiaca, Mantella crocea, and Mantella milotympanum. Although our restriction site-associated DNA (RAD) sequencing approach identified clear genetic clusters, they do not align with current species designations, which has important conservation implications for these imperiled frogs. Moreover, our results suggest that levels of intraspecific color variation within this group have been overestimated, while species diversity has been underestimated. Within major genetic clusters, we observed distinct patterns of variation including: populations that are phenotypically similar yet genetically distinct, populations where phenotypic and genetic breaks coincide, and populations that are genetically similar but have high levels of within-population phenotypic variation. We also detected admixture between two of the major genetic clusters. Our study suggests that several mechanisms-including hybridization, selection, and drift-are contributing to phenotypic diversity. Ultimately, our work underscores the need for a reevaluation of how polymorphic and polytypic populations and species are classified, especially in aposematic organisms.

Distribution and Population Density of the Black-Eared Malagasy Poison Frog, mantella Milotympanum Staniszewski, 1996 (Amphibia: Mantellidae)

Abstract: We provide first data on the natural history of a poorly known species of frog from Madagascar, the black-eared Malagasy poison frog, Mantella milotympanum Although this species has been intensively collected for the pet trade, not even one precise locality was published until 2003 We here provide further distribution records north and south of the known locality Fierenana, but the encountered populations showed variable colour and patterns intermediate between M milotympanum and M crocea, thus supporting the hypothesis that these are conspecific colour morphs, and that M milotympanum might be a junior synonym of M crocea Intensive fieldwork at one site next to Fierenana, in February 2003, yielded some data on population structure and density Snout-vent lengths ranged from 16–24 mm, weights from 04–14 g in adults, with only few subadults and no juveniles found The population density, estimated by mark-recapture, was about 470 individuals per ha, which is a quite high density, taking into consideration that this population had probably been under commercial exploitation in the past We propose that some of the forests in the Fierenana area should be included in the planned extension of Madagascar’s network of protected areas, but a controlled and sustainable exploitation should be allowed in these reserves in order to gain the support of local communities