Maturation and Spawning of the White ShrimpPenaeus schmittiBurkenroad, 1936, Under Large Scale Rearing Conditions

Abstract

AbstractThis paper describes the reproductive performance ofPenueus schmittikept under controlled conditions in a maturation facility of a commercial shrimp farm. A total of 369 females and 368 males of wildP. schmittiwere used to form 9 broodstock groups. Unilateral ablation was performed on females only. Although females were not tagged, the total number of mated females (N =533) indicates that rematuration of the ovaries did occur. Only 9 mated females (1.69%) did not spawn and only 22 mated females (4.20%) of the remaining 524 cases did not produce viable spawns. These results indicate that a large number of viable spawns (94.18%) can be expected fromP. schmitti. A minimum latency period of 6 days for the ovaries to attain full development was observed twice. The highest mating frequency occurred between the 46th and 60th days after unilateral ablation, but mating frequency remained above 2% until the 90th day. The average number of nauplii/female/spawn was 78,961 (N =524) and the average fertilization rate of the eggs was 73.12% (N =297). Usually when the pair of the spermatophores is dislodged from the thelycum of the mated female, a small sperm mass still remains between the third pair of walking legs. This condition did not show any negative effect on the fertilization rate of the eggs and nauplii production. Mating behavior displayed byP. schmittiis also described and includes three distinctive phases: a) chasing, b) mating and c) post‐mating chase.