![]() ![]() In the other two of the 14 species examined, the SDSG are structurally and histochemically similar to serous glands. No variations were observed in the structure or histochemistry of the SDSG of these 12 species that could be attributed to either the phylogeny of individual species or the anatomical location of the glands on the body. ![]() Acidic mucosubstances and lipids were not detected. The SDSG of these 12 species stain positive for neutral mucosubstances and sulfated proteins, suggesting the presence of neutral mucoproteins. The SDSG of 12 of the 14 species are multicellular alveolar glands the secretory cells are filled with eosinophilic granules. We have studied the structure and histochemistry of the sexually dimorphic skin glands (SDSG) of 14 frog species, representing six families, to determine whether these glands constitute a unique type of skin gland. The main near-future threats to the species are habitat changes associated with reduced grazing, along with persecution and collecting. This new species should be classified as globally ‘endangered’ due to its small and fragmented range, and an inferred population decline. The species is extremely range-restricted (less than 500 km2) and occurs only in two disjunct sites within the high rainfall valleys of the Alps north of Biella. The extant population shows a very low genetic variability measured with mitochondrial markers, suggesting that the taxon has suffered a serious population reduction/bottleneck in the past. berus than to its closest relatives occurring in the Caucasus, but can be readily distinguished in most cases by a combination of meristic features as confirmed by discriminant analysis. Morphologically, the new species appear to be more similar to V. berus and other vipers occurring in western Europe and shows closer affinities to species occurring only in the Caucasus. Despite an overall morphological resemblance with Vipera berus, the new species is remarkably distinct genetically from both V. We describe Vipera walser, a new viper species from the north-western Italian Alps. ![]()
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