Natural and artificial spawning strategies with fresh and cryopreserved semen in Rhamdia quelen: Reproductive parameters and genetic variability of offspring

Abstract This study evaluated the reproductive parameters and genetic variability of offspring of Rhamdia quelen from mating by natural spawning and by controlled fertilization with fresh and cryopreserved semen. After hormonal manipulation, three R quelen pairs were used for natural spawning in high-flow tanks, three pairs were used for mating with fresh semen, and another three pairs were used with cryopreserved semen. Matings were performed in triplicate. For matings with fresh and cryopreserved semen, semen from each male was used to individually fertilize oocytes from each female. Pools of semen and oocytes were made, and aliquots of these gametes were taken for fertilization. No differences (P > 0.05) were detected for absolute or relative fecundity, fertilization rate, or egg hatching rate. The use of fresh semen led to a higher (P