In 2007 an unusual crayfish found in food markets in the capital of Madagascar was preliminarily identified as Procambarus 'Marmorkrebs': a new world taxa and the only decapod known to reproduce by parthenogenesis. We present information on the identity, distribution and ecology of this recent invader and attempt to evaluate the threat it poses to Madagascar's biodiversity and to livelihoods. The species appears to be currently limited to the area close to Antananarivo, but is being sold alive on major transport routes. We present molecular evidence of its taxonomic relationships and confirm that the Procambarus present in Madagascar is indeed the parthenogenic taxa. We investigate its reproductive ecology and find Procambarus 'Marmorkrebs' to have an extremely high fecundity; more than six times that of the native crayfish Astacoides. The limited evidence we have suggests that this species poses a serious threat to freshwater biodiversity and that it is likely to damage human livelihoods (through its impact on fishing and possibly rice agriculture). More research is urgently needed but in the meantime action is needed to reduce the rate of spread before it is too late.

Highly diverse and so far apparently untouched by emergent diseases, Malagasy frogs nevertheless are threatened by ongoing habitat destruction, making pro-active conservation actions especially important for preserving this unique, pre-decline, amphibian fauna.

Based on specimens identified by DNA barcoding, we describe the tadpoles of 11 species of treefrogs (Boophis) in the Malagasy family Mantellidae. All tadpoles belong to species of the stream-breeding clade within Boophis. Based on these and other published descriptions of Boophis tadpoles which develop in running water bodies, we tentatively distinguish three ecomorphological guilds for these larvae. Guild A, in which we describe the larvae of B. boehmei, B. reticulatus, B. pyrrhus, B. tasymena, and B. viridis which have few lotic adaptations, their oral disc width being 31-43% of body width, with a single row of 48-81 marginal papillae, and the first upper keratodont row having 58-144 keratodonts. Guild B, in which we describe the tadpoles of B. albilabris, B. madagascariensis, B. luteus, and of an undescribed species here named B. sp. aff. elenae, is intermediate, with an enlarged oral disc, an increasing number of keratodont rows and a lower height of the caudal fin. In these tadpoles, oral disc width is 43-63% of body width, they have one or two rows of 69-164 marginal papillae, and the first upper keratodont row has 164-238 keratodonts. Guild C contains tadpoles with a very large oral disc, living on submerged rocks and stones in stream sections of strong current. In this guild we describe the tadpoles of B. marojezensis and B. sibilans. Their oral disc width is 63-89% of body width, there are multiple rows of many marginal papillae, and the first upper keratodont row has many small keratodonts which are difficult to count, but consistently amount to over 200. In B. marojezensis, the dorsal gap in the marginal papillae rows, apparent in all other species, is closed. These larval morphologies show a rather good fit with recently published molecular phylogenetic data: species groups that were confirmed to be monophyletic in most cases have similar larval morphologies, and, in contrast, where species of the same group have disparate larval morphologies the monophyly of the group is questionable (e.g. the B. majori group). Nevertheless, some cases of convergent evolution are apparent, such as the highly specialized Guild C morphology, which may have evolved separately in the B. albipunctatus group, B. mandraka group, and in some species of the B. majori group.

No abstract

Human-induced conversion of natural habitats into agricultural areas is one of the major drivers for biodiversity loss. In many tropical regions, the matrix habitat area (habitat between fragments of remaining natural habitat) considerably exceeds the area of the original habitat. Therefore, understanding the factors determining matrix quality for animals is a key step to guide conservation action in fragmented landscapes. Matrix habitat, although being often highly disturbed, might provide valuable habitat for some species, serves as buffer zone for remaining natural habitat or corridor between fragments, and hence could be an important component for biodiversity maintenance on a landscape scale. We evaluated the effects of matrix quality on frog diversity in a rainforest ecosystem in Eastern Madagascar. Although frog diversity was affected in all matrix habitats, we found that variation in matrix quality was an important factor. Matrix habitat could serve as valuable habitat and corridor (i.e., high frog diversity along streams in the matrix), as buffer zone (moderate diversity in banana plantations), or was unsuitable habitat for most frog species (very impoverished diversity in secondary vegetation and rice fields). The remaining natural vegetation in and outside protected areas in Madagascar and worldwide is decreasing and will not be sufficient to preserve its biodiversity on a long term. Therefore, we must understand responses of organisms to disturbance in order to create buffer zones and corridors combining both disturbed and natural habitats. Implementing corridors along matrix streams connecting forest habitats might be an important contribution to amphibian conservation in fragmented landscapes.