Evaluation of reproductive performance of pink-shrimp Farfantepenaeus paulensis (Pérez-Farfante, 1967) broodstock in tanks with different water dephts

Abstract

The spawning of unfertilized eggs is commonly observed when the shrimp Farfantepenaeus paulensis is maintained in captivity, and this probably occurs due to the lack of mating in maturation tanks. This study evaluated the effect of water depth on the reproductive performance of this species. Four 3.3 m diameter tanks were used: two tanks had 40 cm of water depth, while the other two were maintained with 80 cm of water. After all females had undergone at least one moulting cycle in captivity, the occurrence of fertilized spawns, number of eggs and fertilization rates were assessed during 33 days. Regardless of treatment, 31 fertilized spawns were sampled (67.7% and 32.3% of fertilized spawns in the tanks of 80 and 40 cm, respectively) demonstrating that mating did take place. No significant differences in fertilization rates were detected between treatments, but the total number of fertilized eggs was two fold higher in the tanks with 80 cm than in those with 40 cm of water depth.