Navegando por Assunto "Dipsadinae"

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Acesso aberto (Open Access)
Análise da variação morfológica de Dipsas catesbyi (Sentzen, 1796) e Dipsas pavonina Schlegel, 1837 (Serpentes: Colubridae: Dipsadinae)
(Universidade Federal do Pará, 2006) LIMA, Ana Caroline de; PRUDENTE, Ana Lúcia da Costa; http://lattes.cnpq.br/1008924786363328
The subfamily Dipsadinae contains about 22 genus of Neotropical fauna and 24 others considered incertae sedis, but with common characters to the Dipsadinae subfamily. The genus Dipsas, Sibon, Sibynomorphus and Tropidodipsas compose the Dipsadini tribe, which is considered a well-based monofiletic group. The tribe is characterized by snakes with a high degree of morphologic specialization, related to the way of feeding and to adaptations to the habitat. The Dipsas genus includes approximately 32 species, distributed from Mexico to South America, it is constituted by thin and elongated snakes, with short and prominent head, great eyes, vertical pupils and absence of mental groove. The species are visible variable in coloration, number of scales and others morphologic characters. This extreme variation has made it difficult to define the limits between the species and to interpret patterns of geographic variation. The great morphologic variation of characters in D. catesbyi and D. pavonina, associate to the difficulty to identify taxons and the lack of information on geographic distributions, justify the necessity of a detailed analysis of these species. For that, the present study was divided in two chapters. The first one corresponds to the analysis of the individual, sexual and geographic variation of D. catesbyi and D. pavonina and a comparison of characters between the two species. The second one corresponds to the analysis of the macrostructure of the cephalic glands in these two species, relating them with others taxons of Dipsadinae.
Acesso aberto (Open Access)
Ecomorfologia de três espécies de Dipsas Laurenti, 1768 e Sibynomorphus Fitzinger, 1843 (Dipsadidae: Dipsadinae)
(Universidade Federal do Pará, 2013) SANTOS, Marina Meireles dos; MARTINS, Marlúcia Bonifácio; http://lattes.cnpq.br/8882047165338427; PRUDENTE, Ana Lúcia da Costa; http://lattes.cnpq.br/1008924786363328
Ecological factors such as the use of the environment and feeding habits may influence the body and cephalic morphology of an organism, however, this can also reflect the phylogenetic lineage. The subfamily Dipsadinae includes South American snakes formed by two clades, one including Geophis and Atractus and another including Dipsas, Ninia, Sibon and Sibynomorphus, which are the tribe Dipsadini. The snakes of this tribe show a high degree of modification in their body and cephalic morphology wich is related to the environment and malacophagous feeding habits. The species of Dipsas and Sibon have specializations related to the use of arboreal environment, offering a better performance in locomotion in the vegetation, while the Sibynomorphus species are mostly adapted to terrestrial environment. Regarding their feeding habits they posses, in varying degrees, a number of changes related to cranial modification and to manipulation and ingestion of gastropods such as slugs and snails. Whereas there is a direct relationship between the shape of the head and the diet, this study aims to analyze the divergences of cephalic morphology between species of diet related to Dipsas and Sibynomorphus, as well as analyze possible convergences between species of these genera and Tomodon dorsatus, species of the tribe Tachymenini, recognized as specialized in slugs. This study is structured in two parts: the first refers to the general introduction, where a broad approach on the morphological adaptations related to feeding habits of Dipsadini, as well as the advantages of the use of geometric morphometry technique in morphological studies; and the second part refers to the work itself, titled "Ecomorphology of three species of Dipsas Laurenti, 1768 and Sibynomorphus Fitzinger, 1843 (Dipsadidae: Dipsadinae)".