Sexual sterilization of harvest-size Penaeus japonicus (Bate) using ionizing irradiation.

摘要

The objective of the present study was to assess the potential of ionizing irradiation to induce sexual sterility in harvest size Penaeus japonicus. P. japonicus were collected from commercial farm ponds (120 males and 174 females), eye tagged for individual identification and weighed (mean male wt of 17.27+or-0.15 g and mean female wt of 22.9+or-0.19 g). Three lots of 40 males and five lots of 34-36 females were then boxed. X-rays were then used to treat one box of males at either 0, 10, or 20 Gy, and one box of females at either 0, 10 or 20 or 25 Gy. A clinical linear accelator with a 4 MeVeletron beam was used to generate X-rays to yield 3.5 Gy min-1 at 80 cm from the target. Different treatment level were achieved by changing the exposure time. After irradiation, shrimp were transferred to their corresponding treatment tank to give a total of 15 reciprocal crosses with two replicates per cross. Analyses of variance indicated that dose, position and the dose x position interaction affected dosimetry (P<0.001). Additionally, the variation in dose received at the different positions increased with the increased level of ionizing irradiation. Survival performance immediately post irradiation was high. However, during the 30-day mating period, significant mortalities were recorded, with no females surviving from the 25 Gy treatment group. Although the survival performance of control shrimp was low (54%), it was significantly greater (P<0.05) than that of the treated shrimp (25%). For male comparisons, treatment males mated with control females had significantly lower hatch rates (11.9%) (P<0.05) than the control males mated with control females (40.7%), indicating that ionizing irradiation had an effect on the ability of male P. japonicus to produce viable offspring..