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Zool Res ; 41(6): 656-669, 2020 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-33171548


Trachypithecus, which currently contains 20 species divided into four groups, is the most speciose and geographically dispersed genus among Asian colobines. Despite several morphological and molecular studies, however, its evolutionary history and phylogeography remain poorly understood. Phayre's langur ( Trachypithecus phayrei) is one of the most widespread members of the genus, but details on its actual distribution and intraspecific taxonomy are limited and controversial. Thus, to elucidate the evolutionary history of Trachypithecus and to clarify the intraspecific taxonomy and distribution of T. phayrei, we sequenced 41 mitochondrial genomes from georeferenced fecal samples and museum specimens, including two holotypes. Phylogenetic analyses revealed a robustly supported phylogeny of Trachypithecus, suggesting that the T. pileatus group branched first, followed by the T. francoisi group, and the T. cristatus and T. obscurus groups most recently. The four species groups diverged from each other 4.5-3.1 million years ago (Ma), while speciation events within these groups occurred much more recently (1.6-0.3 Ma). Within T. phayrei, we found three clades that diverged 1.0-0.9 Ma, indicating the existence of three rather than two taxa. Following the phylogenetic species concept and based on genetic, morphological, and ecological differences, we elevate the T. phayrei subspecies to species level, describe a new species from central Myanmar, and refine the distribution of the three taxa. Overall, our study highlights the importance of museum specimens and provides new insights not only into the evolutionary history of T. phayrei but the entire Trachypithecus genus as well.

Genoma Mitocondrial , Presbytini/genética , Distribución Animal , Animales , Asia Sudoriental , Filogenia , Presbytini/clasificación , Presbytini/fisiología , Especificidad de la Especie
Am J Phys Anthropol ; 144(4): 564-74, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21404233


Tamarins of the genus Saguinus, subfamily Callitrichinae, represent one of the most diverse primate radiations. So far, about 35 taxa have been described, but detailed information about their taxonomy and phylogeny is still lacking. To further elucidate the phylogenetic relationships and the biogeographic history within the genus, and to contribute to a more reliable classification of its taxa, we sequenced the complete mitochondrial cytochrome b gene and the hypervariable region I of the D-loop. Therefore, we mainly used fecal samples from wild tamarins collected during two expeditions to the Peruvian Amazon, an area of high tamarin diversity. Our data suggest that the numerous taxa of the S. nigricollis species group are derived from a common ancestor that separated from the other representatives of the genus ~10 mya. Most taxa of the S. nigricollis group form monophyletic clusters, which mainly originated in a single rapid radiation ~2.9 mya. S. fuscicollis and S. nigricollis appear as polyphyletic taxa, but we could identify various clusters, which are mainly consistent with differences in coat coloration. We could confirm most of the existing taxa as distinct entities and suggest species status for fuscicollis, illigeri, lagonotus, leucogenys, nigricollis, nigrifrons, tripartitus, and weddelli. Our genetic data do not support a separate status for melanoleucus and graellsi, but due to differences in fur coloration, we give them subspecies status. The species group most likely originated in western Amazonia and diversified during the decline of the Acre wetland and the formation of the Amazonian river system.

ADN Mitocondrial/genética , Saguinus/genética , Animales , Análisis por Conglomerados , Regiones Determinantes de Complementariedad , Biología Computacional , Citocromos b/genética , ADN Mitocondrial/química , Heces/química , Geografía , Modelos Estadísticos , Perú , Filogenia , Saguinus/clasificación , Análisis de Secuencia de ADN
Primates ; 52(1): 25-39, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20878203


A detailed understanding of the range of the golden-mantle tamarin, Saguinus tripartitus (Milne Edwards, 1878), in Amazonian Peru and Ecuador is of particular relevance, not only because it is poorly known but also because it was on the basis of its supposed sympatry with the saddleback tamarin (S. fuscicollis lagonotus) that Thorington (Am J Primatol 15:367-371, 1988) argued that it is a distinct species rather than a saddleback tamarin subspecies, as was believed by Hershkovitz (Living new world monkeys, vol I. The University of Chicago Press, Chicago, 1977). A number of surveys have been carried out since 1988 in the supposed range of S. tripartitus, in both Ecuador and Peru. Here we summarize and discuss these issues and provide a new suggestion for the geographic range of this species; that is, between the ríos Napo and Curaray in Peru and extending east into Ecuador. We also review current evidence for the distributions of Spix's black-mantle tamarin (S. nigricollis nigricollis), Graells' black-mantle tamarin (S. n. graellsi), and the saddleback tamarin (S. fuscicollis lagonotus), which are also poorly known, and examine the evidence regarding sympatry between them. We conclude that despite the existence of a number of specimens with collecting localities that indicate overlap in their geographic ranges, the fact that the four tamarins are [corrected] of similar size and undoubtedly very similar in their feeding habits militates strongly against the occurrence of sympatry among them.

Biodiversidad , Preferencias Alimentarias , Saguinus/clasificación , Saguinus/fisiología , Animales , Colombia , Conservación de los Recursos Naturales , Ecuador , Geografía , Perú , Filogenia
Ecology ; 89(5): 1272-86, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18543621


Phytoplankton-grazer dynamics are often characterized by long transients relative to the length of the growing season. Using a phytoplankton-grazer model parameterized for Daphnia pulex with either flexible or fixed algal carbon:nutrient stoichiometry, we explored how nutrient and light supply (the latter by varying depth of the mixed water column) affect the transient dynamics of the system starting from low densities. The system goes through an initial oscillation across nearly the entire light-nutrient supply space. With flexible (but not with fixed) algal stoichiometry, duration of the initial algal peak, timing and duration of the subsequent grazer peak, and timing of the algal minimum are consistently accelerated by nutrient enrichment but decelerated by light enrichment (decreasing mixing depth) over the range of intermediate to shallow mixing depths. These contrasting effects of nutrient vs. light enrichment are consequences of their opposing influences on food quality (algal nutrient content): algal productivity and food quality are positively related along a nutrient gradient but inversely related along a light gradient. Light enrichment therefore slows down grazer growth relative to algal growth, decelerating oscillatory dynamics; nutrient enrichment has opposite effects. We manipulated nutrient supply and mixing depth in a field enclosure experiment. The experimental results were qualitatively much more consistent with the flexible than with the fixed stoichiometry model. Nutrient enrichment increased Daphnia peak biomass, decreased algal minimum biomass, decreased the seston C:P ratio, and accelerated transient oscillatory dynamics. Light enrichment (decreasing mixing depth) produced the opposite patterns, except that Daphnia peak biomass increased monotonously with light enrichment, too. Thus, while the model predicts the possibility of the "paradox of energy enrichment" (a decrease in grazer biomass with light enrichment) at high light and low nutrient supply, this phenomenon did not occur in our experiment.

Daphnia/fisiología , Ecosistema , Eucariontes/fisiología , Conducta Alimentaria/fisiología , Modelos Biológicos , Fitoplancton/fisiología , Animales , Simulación por Computador , Fertilizantes , Agua Dulce , Océanos y Mares , Dinámica Poblacional