Literaturdatenbank
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Garbin, R. C., Fernandes, D. S., & Pinto, R. R. , Morphological aspects of the geographic and ontogenetic variation in the brazilian freshwater turtle acanthochelys radiolata (mikan, 1820) (pleurodira: Chelidae) - abstract. Unpublished paper presented at Program and Abstracts of the Tenth Annual Symposium on the Conservation and Biology of Tortoises and Freshwater Turtles.
Added by: Admin (06 Jan 2014 18:22:49 UTC) |
| Resource type: Conference Paper BibTeX citation key: Garbin2012 View all bibliographic details  |
Categories: General Keywords: Acanthochelys radiolata, Chelidae, Habitat - habitat, Schildkröten - turtles + tortoises, Südamerika - South America, Systematik - taxonomy Creators: Fernandes, Garbin, Pinto Collection: Program and Abstracts of the Tenth Annual Symposium on the Conservation and Biology of Tortoises and Freshwater Turtles |
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| Abstract |
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The freshwater turtle Acanthochelys radiolata is restricted to Brazil's Atlantic Forest domain and its geographic distribution range over 2000 km along the coastal zone from the state of Alagoas to Rio de Janeiro and southern Minas Gerais. Due to its wide distribution, the aim of this study is to document the intraspecific variation and the sexual dimorphism of this species based on morphology. We analyzed 339 characters (107 morphometric, 12 meristic, 187 morphological and 33 regarding color pattern) of 41 individuals. The specimens were separated into nine populations a priori and tested by the Principal Component Analysis in order to observe the geographic variation. Results show a high polymorphism in this species. Morphometric data agrees with the literature and revealed a sexual dimorphism where females have higher proportions than males. Meristic data showed low variability and may be associated with the diagnosis of this species or genus. The highest variability was observed in morphological and color pattern characters. Two main color patterns were recognized for carapace and three for the plastron. Head, neck, limbs and tail had a dark dorsal surface and a yellowish ventral surface. Diagnostic characteristics of the species, such as the rounded tubercles in the neck and the presence of radiated striations on the carapace, varied considerably. New data bring important information on the species, such as the presence of valve-like flaps in the corner of the mouth, mesodorsal surface of the head covered with smooth skin and the length of the intergular scute smaller or equal as its distance to the abdominals. Ontogenetic variation shows different color pattern of the plastron and limbs beginning from the fourth month of life. The Principal Component Analysis revealed differences between the morphometric parameters of females from the two populations of the state of Rio de Janeiro and Santa Teresa, Espírito Santo. Despite this variation, the considerable overlapping in character states among specimens from different localities precluded the differentiation of populations of A. radiolata based on morphology. This study is a contribution to the taxonomic knowledge of the species.
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