Alimentação inicial do Jundiá, Rhamdia voulezi Haseman 1911: efeitos da privação alimentar sobre o crescimento e padrões na seleção de presas ao longo do período larval

Detalhes bibliográficos
Ano de defesa: 2013
Autor(a) principal: Lima, Ariane Furtado de lattes
Orientador(a): Makrakis, Maristela Cavicchioli lattes
Banca de defesa: Kashiwaqui, Elaine Antoniassi Luiz lattes, Tataje, David Augusto Reynalte lattes, Makrakis, Sérgio lattes
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Estadual do Oeste do Paraná
Toledo
Programa de Pós-Graduação: Programa de Mestrado Recursos Pesqueiros e Engenharia de Pesca
Departamento: Centro de Engenharias e Ciências Exatas
País: BR
Palavras-chave em Português:
Palavras-chave em Inglês:
Área do conhecimento CNPq:
Link de acesso: http://tede.unioeste.br:8080/tede/handle/tede/1917
Resumo: The effects of feeding privation on growth of larvae of jundiá Rhamdia voulezi as well as the feeding preference during larval period were evaluated. For this purpose two experiments were conducted which began soon after complete absorption of the yolk sac, the fourth day after hatching (DAH). The feeding privation experiment was performed in 8 treatments consisting of different diets, including the control treatment (CT) in which there was no food supply. The food was provided for the first time in the 4th, 5th, 6th, 7th, 8th, 9th and 10th DAH corresponding to treatments: T4, T5, T6, T7, T8, T9 and T10, respectively. The food consisted of zooplankton and newly hatched artemia. We performed 3 trials of selectivity to analyze the feeding preference throughout the larval period, comprising different larval stages and classes of standard length. In this, the larvae were fed exclusively on zooplankton collected from fish ponds. The results demonstrated that the larvae fed on the fourth to sixth DAH had a significantly higher growth than those fed later, from the seventh DAH. The point of no return was recorded in the same period in the 7th DAH. With respect to feeding selectivity, there were variations in the patterns of prey selection in different days of life analyzed. Initially on the 5th DAH, preflexion stage, larvae strongly selected rotiferas (unidentified) and cladocerans (Diaphanosoma spinulosum, D. brevireme, Moina sp., M. micrura, M. minuta). In the remaining days of life examined, the cladocerans continued to be strongly selected. However on the 8th DAH, flexion stage, they selected less intensely the copepods Argyrodiaptomus azevedoi and Termocyclops decipiens and more strongly A. furcatus, Notodiaptomus spinuliferus and Metacyclops mendocinus at 10 DAH, postflexion stage. The delay of the first feeding drastically affected the growth of the larvae, and that if feeding is started before the point of no return there are chances of recovery. So, it is important to have suitable availability of food, with a variety of type and size so that they can compensate for the morphological limitations of larvae in the early of their development. Concomitant to its growth, the larvae tend to specialize in certain prey items. The size of prey consumed is related to the size of the larvae and the gape size. Initially larvae have a preference for smaller prey, rotifers and cladocerans, and later when they are more developed prefer to feed on larger prey, the copepods.