Caracterização do desenvolvimento embrionário e desempenho de pós-larvas de tambaqui (Colossoma macropomum, Cuvier, 1818) alimentados com diferentes dietas

Abstract

The objective of monitoring the embryonic development of the tambaqui (Colossoma macropomum) through induced reproduction. Embryonic development presented the following sequence of events, (minutes after fertilization-MAF) when incubated at 28, 7 0C. The five MAF, the cytoplasm became more evident in the animal pole, forming a disc of cytoplasm, highlighting an increase in perivitelline space. The cleavagens occurred between 25 and 60 MAF. With 87 MAF, it was observed the morula stage, characterized by the presence of more than 64 blastomeres. Was observed with 140 MAF, the blastula stage, characterized by presenting dome above the mass of the yolk. At gastrula stage, can be viewed epibolia movement of embryonic cells, observed with 167 MAF, when approximately 30% of the yolk was covered. With 292 MAF had around 80 to 90% of epibolia and with 325 MAF, it was observed the end of the movement, which was completed with the formation of a portion called yolk plug. At the beginning of the Histogenesis and organogenesis, with 370 MAF, noted the development of cephalic regions, tail and development of the first somitos. The optic vesicle became more obvious MAF 440, occurring simultaneously with the increase in the number of somitos. The tail has been partially disengaged from the vitelline sac to 550 MAF. The embryo has swimming movement inside the chorionic membrane until the moment in which the larvae broke out and became free. Hatching of larvae occurred 774 MAF (12:54h), the equivalent for 360 hours-degree.