A new and practical application of JH antagonist KK-42 to promoting growth of shrimp Penaeus schmitti

The shrimps (Penaeus schmitti), 0.6–0.8 cm long, were soaked for 1 min in juvenile hormone antagonist KK-42 solution at a concentration of 1.95 × 10− 4 mol/L, and then cultured in normal way. The body weight of animals rose with increasing culture time in all groups, but was higher in KK-42 treatment. The increase rate of body weight of treatment group was 167% and 68% higher than control group at 30th day and 60th day, respectively; the body weight rose by 42.5% at 90th day and 22.1% at 120th day. Histological observations showed that the number of acini of mandibular organ increased gradually as animals grew, and the diameter of acinus-forming cells was statistically bigger at 120th day than at other times. After KK-42 treatment, both the number of acini and the diameter of gland cells decreased in the entire experiment observed. The results indicated the inhibition of anti-juvenile hormone KK-42 on the development of mandibular organ in P. schmitti.