The objective of the research was to test the effect of a molusquicida (Niclosamida) in the tadpoles control and not to compromise the development and survival of common carps in the egg development until 28 days age. Six experiments were carried out and involved six tadpoles and fishes development phases (egg, 7, 12, 21, 27 and 34 days). A completely randomized experimental design, with five treatments (0.00, 0.10, 0.15, 0.20 and 0.25 ppm niclosamida) and four replicates, was used. Post-larvae and tadpoles stayed together in a density of 100 units of each from a nursery production. Twenty aquariums of six liters were all supplied until the beginning of the experiment, when the water flow was interrupted. Niclosamida efficiency did not affect the fertilization phase of tadpoles and carps eggs. In the first week, the levels of 0.25, 0.20, 0.10 ppm affected tadpoles growth at 48, 65 and 115 minutes after product application and showed no siginificant effect on the post-larvae of common carp. The 0.15 ppm level of Niclosamida at 27 days of age tended to provok higher tadpoles mortality and higher post-larvae of common carp survival. The 0.10 ppm level of Niclosamida also tended to show the best result at 21 days in post-larvae of common carp and tadpoles.
anuros; Cyprinus carpio; fingerlings; niclosamida; tadpole
