Os aspectos reprodutivos e o sistema de acasalamento de Squalus albicaudus (Squaliformes, Squalidae), incluindo revisão sobre paternidade múltipla em Elasmobrânquios

• Autor(a) principal: Machado, Felipe Lamarca
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/13859
• topic: Microsatellite DNA; Paternity Analysis; Polyandry; Reproduction; Sharks; Análise de Paternidade; Microssatelite DNA; Poliandria; Reprodução; Tubarão; CNPQ::CIENCIAS EXATAS E DA TERRA::OCEANOGRAFIA::OCEANOGRAFIA BIOLOGICA

Understanding the behavior and reproductive habits of elasmobranchs and the determination of reproductive biology parametersare necessary for species conservation, as sharks and rays are very vulnerable to overfishing. Several cases of multiple paternity were recorded for species of sharks and rays, but their ecological and evolutionary advantages are not yet understood. Sharks of the species Squalus albicaudus captured on the southeastern coast of Brazil were used to investigate reproductive aspects and the mating system of the species. Thirteen pregnant females were analyzed to evaluate the fecundity, reproductive cycle and the reproductive pattern and nine litters were use to analyze the mating system through the genetic analysis of paternity. In addition, a scientiometric analysis of the studies that investigated the occurrence of multiple paternity in elasmobranchs with a phylogenetic approach. Samples obtained had a mean fecundity of 2.84 pups per litter, asynchronous reproduction and a continuous reproductive cycle, with no correlation between the total length of the females and the number of embryos per litter. Evidence of multiple paternity was observed for two litters, indicating the presence of behavior for the species. In the scientiometric analysis 36 studies were obtained for 29 species, restricted to a few genera and families. In phylogenetic terms we observed that the behavior is well diffused in the group, even thought there are orders not yet studied. With the theoretical revision we completed important questions aboutmultiple paternity behavior in elasmobranchs, the multiple paternity frequencies obtained in the studies may not correspond to the population as a whole, and multiple paternity in elasmobranchs may be related to imbalance between the optimal mating rates of males and females and indirect benefits. The present study is the first that evaluates the reproductive aspects and the mating system of the species Squalus albicaudus and indicates that MP is well diffused in elasmobranchs.