Programa de Pós-Graduação em Zoologia - PPGZOOL/ICB
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2343
O Programa de Pós-Graduação em Zoologia (PPGZOOL) do Instituto de Ciências Biológicas (ICB) foi consolidado como um convênio entre Universidade Federal do Pará (UFPA) e Museu Paraense Emílio Goeldi (MPEG).
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Navegando Programa de Pós-Graduação em Zoologia - PPGZOOL/ICB por Autor "AVELAR, Áderson Araújo"
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Item Acesso aberto (Open Access) Ontogenia e dimorfismo sexual nas espécies de guaribas vermelhos, gênero Alouatta lacépède, 1799 (Primates, Atelidae)(Universidade Federal do Pará, 2007) AVELAR, Áderson Araújo; SILVA JÚNIOR, José de Sousa e; http://lattes.cnpq.br/4998536658557008Sexual dimorphism in red howlers is relatively well documented for adult specimens and in all species of the genus Alouatta adult males are larger than females. However, sexual dimorphism among these species is not homogeneous and A. seniculus is considered the more dimorphic species. Moreover, sexual dimorphism among non adult ages is poorly known. The aim of this work is to evaluate the ontogeny of sexual dimorphism in five closely related species of howler monkeys: Alouatta seniculus, A. juara, A. macconnelli, A. puruensis, and A. nigerrima, and establish a method for identification of more accurate age classes in these taxa. A total of 28 cranial and hyoidean dimensions were extracted from 329 crania, and pelage color of 192 skins was examined. Sexual dimorphism in each age class was verified using Student’s t Test, and Discriminant Function Analysis (DFA) was employed to verify the consistence of the age groups. Analysis of Variance (ANOVA), followed by Tukey’s pairwise comparisons test, was applied to analyze growth in some adult cranial dimensions in A. macconnelli. Five adult age classes were recognized through the evaluation of oclusal wear and cranial suture closure; however, these classes were not recognized by cranial dimensions only. Non adult age classes did not exhibit sexually dimorphic measurements on cranium, and sexually dimorphic characters appeared at the first adult age class. A. macconnelli was the more dimorphic species, and sexually dimorphic characters arose earlier in this species. In contrast, A. nigerrima exhibited a smaller number of sexual dimorphic characters, suggesting that differences in behavior of this species play an important role on dimorphism development. Among all cranial dimensions, the canine length was the most sexually dimorphic. In females, this dimension ranged about 60% of that in males. The sexual dimorphism was not evident in the neurocranium. In A. macconnelli, seven cranial dimensions in females and five in males exhibited variation among the adult age classes. Ontogenetic differences in pelage color were very subtle and refer to bleaching of chromatic fields in different degrees. Ontogenetic modifications on the cranium are more intense in males than females, leading to a narrower and more flattened cranium in adult specimens of the former. Some age classes could not be tested for some species due to the inadequate number of specimens in the collections analyzed.