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| Author(s): |
Ligia Pizzatto do Prado
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2006-04-28 |
| Examining board members: |
Otavio Augusto Vuolo Marques;
Selma Maria de Almeida Santos;
André Victor Lucci Freitas;
Ricardo Jannini Sawaya;
Wesley Rodrigues Silva
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| Advisor: | Otavio Augusto Vuolo Marques |
| Abstract | |
Morphological syndromes related to macrohabitat use have been detected in many snakes. However, body morphology can be also related to phylogenetic lineage and for this reason ecomorphological studies are better when using comparative methods. Body morphology and its relationship with macrohabitat use was compared among the Boidae snakes, using preserved specimens deposited in museum collections. Arboreal species are more flattened laterally and have relative longer tails, than terrestrial or aquatic species, even after removing phylogenetic effects. Sexual dimorphisms occurs in SVL, relative head size, tail length, body circumference, lateral flatness of the body and spur size. However, SVL dimorphism are absent in some species with ritual combat (Epicrates ssp.) and tail dimorphism is absent in arboreal species. In most cases sexual dimorphism results of diferential growth in sexes because it does not occur in newborn. Optimizations of morphological characters and microhabitat use on two phylogenetic hypotheses suggest that Boinae had little modifications during the evolution, and most of that represent autapomorphies in species or subspecies level. Both hypotheses agree that the ancestor of Boinae was a short-tailed snake, with medium-size body circumference, small head, low SSD and semi-arboreal, but they disagree how would be the ancestor in terms of body size and lateral flatness of the body. Data on the reproductive biology of Neotropical Boinae are mostly restricted to captive snakes. This work presents information on reproduction of these snakes, using preserved specimens from collections, and compares the results to those available in literature to the subfamilies Pythoninae and Erycinae. The Neotropical Boinae presented vitelogenesis mostly during the autumn and winter (except for Corallus hortulanus and Eunectes murinus), pregnancy from late winter to spring and birth from late spring to summer. Mating was only recorded to Boa constrictor spp. and Epicrates cenchria crassus, from autumn to early winter. Vitellogenis timing was more extended in Corallus hortulanus, the pregnancy was recorded from late summer to early winter, and birth from autumn to winter. In Eunectes murinus vitellogenesis occurred in the spring, pregnancy in the summer and birth from autumn to winter. Testicular cycles were seasonal in Boa c. constrictor (peak occurring in the summer) and in Epicrates c. crassus (peak occurring in the summer-autumn), but continuous in the other species (C. hotulanus, E. c. assisi e E. c. cenchria). Clutch size differs among species but it was related to SVL. The reproductive pattern in most Boinae species apparently differed from the Madagascan boas and Erycinae species but was very similar to the pattern recorded to most Pythoninae snakes. Clutch size and offspring size is similar among Boinae and Pythoninae snakes (AU) | |