INCREASED LARVAL PRODUCTION OF Penaeus setiferus BY ARTIFICIAL INSEMINATION DURING SOURCING CRUISES

ABSTRACT The inability of shrimp culturists to produce sufficient quantities of fertilized penaeid eggs in captivity has sustained the practice of collecting mature wild females offshore for immediate spawning. However, in the case of open thelycum penaeids, offshore collections are often unproductive because mature wild females are seldom found in the mated (spermatophore attached) condition. In this study, artificial insemination was investigated as a means of obtaining fertilized eggs from unmated mature female Penaeus setiferus collected offshore. A total of 59 artificial inseminations were performed in conjunction with 4 cruises in the western Gulf of Mexico. Sperm was removed from spermatophores of males found within the catch and attached between the third and fourth pairs of pereiopods of unmated, mature females which were then chilled to 20°C to inhibit spawning until return to the laboratory. Of 53 spawns produced by artificially inseminated females, at least 41 (77%) resulted in fertilized eggs and nauplii (range: 100 to 260,000 nauplii per spawn). Of the 41 fertile spawns, 29% produced 50,000 or more nauplii and 20% produced more than 100,000 nauplii per spawn. Approximately 2 million larvae were produced by artificial insemination, while only about one million were obtained from naturally mated females on the same cruises. Thus, the production of nauplii from the cruises was tripled by using artificial insemination in addition to spawning of naturally inseminated females.