Comparative growth of selected and non-selected Kuruma shrimp Penaeus (Marsupenaeus) japonicus in commercial farm ponds;: implications for broodstock production

Selected and non-selected stocks of the Kuruma shrimp Penaeus (Marsupenaeus) japonicus (Bate, 1888) were reared from postlarvae to harvest size in commercial ponds and their growth rates compared. The three stocks examined were: progeny of wild broodstock (G(1)); progeny of first generation domesticated broodstock (G(2)) mass-selected for maximum size at harvest and conditioned for 5 months in controlled environment tanks, and; progeny of high-growth broodstock (H(4)) originally selected at G(1) for maximum size at harvest from a commercial pond and subsequently reared in controlled condition tanks for three generations. During the experiment, variations in physical conditions in the ponds fluctuated but appeared to be within the range tolerated by P japonicus. The results demonstrated significant gains in the weight at first harvest for the selected stocks. Compared to the progeny of wild stocks, there was a 9.3% increase in the mean weight at first harvest of G(2) stocks and a 14% increase in the H(4) stocks. The ability of the H(4) tank reared stocks to retain their capacity for superior growth in farm ponds has significant implications for selective breeding of this species. Sub-sets of specific pathogen free (SPF) lines of selected stocks, maintained in biosecure conditions, could provide a valuable and sustainable genetic resource for stocking farms or reestablishing farm populations in the event of stock losses due to disease outbreaks or other factors. (C) 2004 Elsevier B.V. All rights reserved.