Evaluation of milt quality of the yamú Brycon amazonicus under hormonal induction

Two-year old and first sexual maturation male Yamú Brycon amazonicus were selected, according to the presence of semen under gentle abdominal pressure (body weight BW 1.300 ± 3 g; Total length TL 41.4 ± 0.2 cm, mean ± SEM). Five treatments were carried out: three with mGnRHa (10, 15 and 20 µg/kg in a single dose), one with carp pituitary extract CPE (4.4 mg/kg in two applications, 10 and 90 % with a 12 h interval) and a treatment control with application only of saline solution (0.9%). The volume, spermatic concentration, spermatocrit, fertility rate, percentage of live spermatozoa, motility and activation time were evaluated. The CPE caused an increase in volume, a decrease in sperm concentration and spermatocrit. A positive linear regression between the spermatocrit and the sperm concentration was found (p0.05). For the other parameters evaluated, there were no differences, between the hormones utilized, or between them and the control. It was concluded that the CPE influences, the sperm fluidity, increasing the volume and decreasing the concentration, while the mGnRH-a does not cause any quantitative or qualitative changes in the yamú semen.