Estimulação da espermiação em curimbatá Prochilodus scrofa (Steindachner) através de aplicaçoes de HCG (Ostheichthyes, Characiformes, Prochilodontidae)

Sperm of 180 three year old males of curimbata, Prochilodus scrofa (Steindachner, 1881), was collected to verify the possibility of utilization of these males more than one time, and to know how long after the hormonal induction would occur the highest production of milt. This experiment was carried out in 1991 and 1992. After sperm was collected, each male was stimulated by the first injection of five IU/g of hCG. Then, milt was collected at 8, 16, 24, 48, 72 and 96 hours before and after the first dose and at 16 hours before and after the second one. Mean volume values were, before hormonal injection, 0.22ml and after two doses of hCG, 106ml. Maximal production occurred between 16 and 24 hours after induction. Mean values of sperm concentration and total number of sperm were, before hormonal induction, 31.16xl06/mm3 and 6.79x109 and after two doses, 21.46x106/mm3 and 22.15x109, respectively. There were no statistical differences between males receiving two or one doses of hCG concerning fertilization. Results indicated that males of Prochilodus scrofa may be induced a second time 14 days apart, what increases their reproduetive efficiency.