NATURAL AND INDUCED REPRODUCTION OF Hoplias malabaricus (BLOCH, 1794), IN FISH EXPERIMENTAL, IN THE REGION OF URUGUAIANA, BRAZILIAN PAMPA
Abstract
The results of natural and induced reproduction in experimental fish ponds of Hoplias malabaricus (BLOCH, 1794) are presented in this work. The study took place in Uruguaiana County, Brazilian Pampas. The research was held at pisciculture section of PUCRS-Campus Uruguaiana. The influence of physicochemical factors on biological reproduction aspects was verified according to the obtained values, which were considered normal for fish cultivation. The experiment was made in 40 square meters fish ponds with 1.40 m water depth. It was used two males for each female during the reproduction process. On the natural reproduction it was held two treatments (A and B) repeated twice. The water volume at fish pond 1 (T1) was reduced to 80 cm in order to promote stress, besides a small temperature variation to stimulate spawning. In fish pond 2 (T2), the natural reproduction was evaluated without the reduction of water volume. On the induced reproduction, it was used HCG with a break of 8 hours for each hormonal application on T1 and T2. On T1, the application was in a proportion of (400 UI/kg) beneath 1.40 m water depth and on T2 the same dose of HCG reducing the water volume to 80 cm. We may conclude that on the induced reproduction there was time decrease until the spawn occurrence, but the natural reproduction has presented a small increase observed during this period and a high rate of fertilization, over 96%. So, we may conclude that both, natural and inducted reproduction, are efficient and can be used in order to obtain Hoplias malabaricus eggs and larva and that the reproduction is obtained in a shorter time when water volume in the fish ponds is reduced.Downloads
Published
2008-01-16
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