Tese Fabio Bittencourt.pdf - Caunesp

2.0 ABSTRACT
The aim of this work was to substantiate the knowledge of protein requirements
of female pacu, Piaractus mesopotamicus evaluating the oocytes quality,
reproductive index and the embryo ontogeny when kept in cages. For that, the
experiment was conducted in the Centro de Desenvolvimento de Tecnologias
para Piscicultura em Tanques-rede located in the Refúgio Biológico, Santa
Helena county – PR. Were distributed in a completely randomized design,
composed of four treatments (crude protein tenors – PB %) and four replicates,
224 breeding pacu P. mesopotamicus in 16 cages (5,0 m 3 each). Were
formulated four diets containing 18, 24, 30 and 36% of PB, being isocalorics,
isocalcium and isophosphoric to feed the fish. In the period which females and
males were able to spawn (December/2009 to January/2010) were selected
and applied the doses of carp pituitary extract. Were collected oocytes samples
before the preparatory stage and at the spawning moment. They were divided
in parts as follows: Gilson’s solution (size or oocytes diameters) and in formol
(histological evaluations). The material reminder was fertilized and placed on
experimental conic incubators (20L) to, subsequently, to collect the eggs,
embryos and larvae for monitoring embryonic development and measurement
the others reproductive parameters. The oocytes diameter percentage
frequency distribution collected before the 1 st hormonal application showed
unimodal behavior for the lower protein content and polymodal trends for the
other treatments. At the moment of spawning, similar situation was verified. The
fertilization and hatching rates were lower in treatments with 30% of PB having
differences (p