Ontogenia de larvas de piracanjuba, Brycon orbignyanus Valenciennes (1849) (Characiformes, Characidae, Bryconinae)
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Data
2006-05-12
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Universidade Federal de Viçosa
Resumo
Com o objetivo de descrever a ontogenia das larvas de piracanjuba Brycon orbignyanus (Valenciennes, 1849) (Characiformes, Characidae, Bryconinae), entre zero e 172 horas após eclosão, foram utilizados, aproximadamente, 4.000 exemplares, resultantes de reprodução induzida, provenientes da Estação de Pesquisa e Desenvolvimento Ambiental de Volta Grande, Conceição das Alagoas, MG. As larvas foram coletadas a cada meia hora nas incubadoras, em que as características físicoquímicas da água foram 26,18 ± 0,40 oC, pH 6,62 ± 0,17, 6,42 ± 0,17 mg/l de O2, 0,05 mS/cm e 0% de salinidade. Os exemplares foram fixados em solução de formol neutro tamponado a 4%, para os estudos morfológico aparente e morfométrico, e em fluído de Bouin, por 6 a 8 horas, a temperatura ambiente, para os estudos histológicos e do sistema endócrino gastroenteropancreático. A cada 12 horas foi observado o comportamento das larvas, em particular, o natatório, alimentar, canibalismo e predação, e a formação de cardume. As larvas de piracanjuba (Brycon orbignyanus), ás 28 horas após eclosão (CP = 6,35 ± 0,13 mm), desenvolveram um conjunto de características morfológicas, histológicas e comportamentais que as tornaram predadoras ativas e capazes de superar uma das etapas críticas da larvicultura, o início da alimentação exógena. Às 72 horas após eclosão (CP = 9,13 ± 0,18 mm), elas tornaram-se capazes de superar outra fase crítica, que coincide com o momento em que a bexiga gasosa torna-se totalmente inflada. O desenvolvimento ontogênico apresentado pelas larvas de piracanjuba (Brycon orbignyanus), até 172 horas após eclosão (CP = 3,62 a 11,94 mm), relacionadas com a detecção e seleção do alimento, alimentação, respiração, locomoção e formação de cardumes, favorecem a sobrevivência.
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.
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.
Descrição
Palavras-chave
Piracanjuba, Histologia, Ontogenia, Teleostei, Brycon orbignyanus, Piracanjuba, Histology, Ontogeny, Teleostei, Brycon orbignyanus
Citação
MACIEL, Cláudia Maria Reis Raposo. Ontogeny of piracanjuba Brycon orbignyanus Valenciennes (1849) (Characiformes, Characidae, Bryconinae) larvae. 2006. 244 f. Tese (Doutorado em Genética e Melhoramento de Animais Domésticos; Nutrição e Alimentação Animal; Pastagens e Forragicul) - Universidade Federal de Viçosa, Viçosa, 2006.