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We studied molecular and morphological variation in small fruit-eating bats (Artibeus) in northern South America to establish species boundaries, evolutionary relationships, and distributional limits. Although this is a speciose genus with some of the most common bats in Neotropical forests, resolution of taxonomy and their identification has been difficult. Our molecular phylogeny based on Bayesian and parsimony analyses of cytochrome b variation includes a well supported topology of A. glaucus glaucus sister to a clade of A. gnomus and A. glaucus bogotensis indicating that A. glaucus is a paraphyletic amalgam. A re-assessment of morphology corroborates differences between A. g. bogotensis from the Andean valleys of Colombia east into the Guianas and A. g. glaucus from western Amazonia. Thus, we recognize A. bogotensis and A. glaucus as distinct and allopatrically occurring species. Based on a Kimura-2 parameter model of substitution for cytochrome b, there was 1.2% sequence divergence within A. bogotensis, and 9.5% sequence divergence between A. bogotensis and A. glaucus. Compared to A. glaucus, A. bogotensis has prominent white facial stripes, a less hirsute interfemoral membrane, less robust orbitorostral region, and also lacks a small third lower molar. Within the Guiana region, there are three species with overlapping distributions (A. bogotensis, A. cinereus, and A. gnomus), however, they are sympatric only within the interior lowland forest near savannas. All other habitats including coastal forest, lowland forest, savanna, and highland forest have only two sympatric species, one of which is relatively more abundant (> 70%)
We surveyed mammals at a site in Napo Province, eastern Ecuador, in 1995 and 1996. We recorded 66 species at the site, including four species new to the fauna of Ecuador (Cynomops paranus, Eumops hansae, E. maurus, and Molossus coibensis), two species recorded for the first time from eastern Ecuador (Lichonycteris obscura and Promops centralis), and a new record for Napo Province (Artibeus gnomus). Although species richness of bats is among the highest recorded in any single area in western Amazonia, the inventory still probably considerably underestimates total species-level diversity.
We analyzed the phylogenetic relationships of all eleven currently recognized species of large Artibeus using the cytochrome b mitochondrial gene. The topology from a maximum parsimony analysis included: (1) A. obscurus and A. planirostris as sister species with successively basal lineages of (2) A. amplus, (3) a clade with A. lituratus and A. intermedius, (4) A. jamaicensis, (5) a clade of A. inopinatus sister to A. hirsutus and A. fraterculus, (6) A. fimbriatus, and (7) the most basal lineage of A. concolor. The individual species were monophyletic and well supported by bootstrap and decay values. The monophyletic clade of ((((obscurus + planirostris) + amplus) + (lituratus + intermedius)) + jamaicensis) was also highly supported, although some of the interspecific relationships were less so. Contrary to previous hypotheses of species limits based on a presumed intergradation in body size, A. jamaicensis and A. planirostris do not form a monophyletic group, refuting their conspecificity and supporting an earlier study concluding that these two taxa represent separate morphological populations. An analysis with A. jamaicensis and A. planirostris constrained as sister-taxa resulted in a tree 8 steps longer. In addition, the low genetic pair-wise difference between A. lituratus and A. intermedius (2.8% with Kimura-2 parameters) warrants closer examination of their species limits.
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