Two females with colored urogenital organ, rounded off abdomen, color egg released, and uniform size and four males with semen released under abdomen pressure were selected to determine the best insemination dose for artificial fertilization of grey jundia, Rhamdia quelen (Quoy & Gaimardm, 1824), oocytes. Females and males received two doses of carp pituitary extract: the first one of 0.5 and 0.25 mg.kg-1 and the second of 5.0 and 2.5 mg.kg-1 for females and males, respectively. Both females produced 169 g of eggs with 1,141 oocytes.oocytes g-1. The males produced a total of 23.6 mL of semen. From all males semen pool sperm concentration (1.97 x 10(10) spermatozoa.mL-1), survival sperm index (96%) and sperm morphology were analyzed (66.9% of normal spermatozoa). The fertilization assay was conducted as a complete randomized experimental design with five treatments ((6x10³, 6x10(4), 6x10(5), 6x10(6), 2x10(7) spermatozoa.oocyte-1) and four replications. After eight hours of incubation, the fertilization rates for each treatment were analyzed. The best spermatozoa.oocyte-1 rate was of 89.497 spermatozoa.oocyte-1 that produced a maximum fertilization rate of 86.68%.
insemination dose; reproduction; Rhamdia quelen
