Ontogenia de larvas de piracanjuba, Brycon orbignyanus Valenciennes (1849) (Characiformes, Characidae, Bryconinae)

• Autor(a) principal: Maciel, Cláudia Maria Reis Raposo
• Data de Publicação: 2006
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1791
• topic: Piracanjuba; Histologia; Ontogenia; Teleostei; Brycon orbignyanus; Piracanjuba; Histology; Ontogeny; Teleostei; Brycon orbignyanus; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL

With the aim of describing the ontogeny of the piracanjuba Brycon orbignyanus (Valenciennes, 1849) (Characiformes, Characidae, Bryconinae) larvae, among zero and 172 hours post-hatching, approximately 4.000 specimens, resultants of induced spawning, from the Environmental Development and Research Station of Volta Grande, Conceição das Alagoas, MG, were used. The larvae were collected every half hour in the incubators, in which the water s physiochemical characteristics were 26,18 ± 0,40 ºC, pH 6,62 ± 0,17, 6,42 ± 0,17 mg O2/ l, 0,05 mS/cm of electrical conductivity and 0% of salinity. The collected specimens were fixed in 4% neutral buffered formalin solution, for the apparent morphologic and morphometric studies, and in Bouin fluid, for 6 or 8 hours, at ambient temperature, for the histological and gastroenteropancreatic endocrine system studies. Each 12 hours the larvae behavior was observed, in particular, the natatory, feeding, cannibalism and predation, and the schooling formation. The piracanjuba larvae (Brycon orbignyanus), at 28 hours posthatching (SL = 6,35 ± 0,13 mm), developed a set of morphologic, histological and behavioral characteristics that became them active predators, able of overcoming one of the critical stages of the larval rearing, the onset of the exogenous feeding. At the 72 hours post-hatching (SL = 9.13 ± 0.18 mm), they became capable to overcome another critical phase, that coincides with the moment in witch the swim bladder becomes totally inflated. The ontogenic development presented by the piracanjuba larvae (Brycon orbignyanus), until 172 hours post-hatching (SL = 3.62 to 11.94 mm), related with the food detection and selection, feeding, breathing, locomotion and schooling behavior, it favor the survival.