Comparative study of reproductive characteristics of the euryhalinetilapia, Sarotherodon melanotheron heudelotii in fresh and sea waters

摘要

Reproduction characteristics of the euryhaline tilapia, Sarotherodon melanotheron heudelotii, in fresh and sea water were studied. Absolute and relative fecundities are not significantly different; the density of eggs remains stable, on the other hand, the size and consequently the weight of eggs is significantly lower in sea water. The effects of stress are more important in seawater and had as a consequence a higher mortality of the parents and a lower number of consecutive spawns collected. The aggressiveness of the parents was increased in both environments due to fish couple isolation