Effect of high water temperature on the survival, moulting and food consumption of Penaeus (Marsupenaeus) japonicus (Bate, 1888)

The kuruma shrimp, Penaeus (Marsupenaeus) japonicus (Bate, 1888), is a valuable aquaculture species in Queensland, Australia. The shrimp is supplied live to the Japanese market and must survive emersed transport for up to 36 h. In-transit mortality after harvest from high water temperatures (> 30 degreesC) has been reported by the industry, and a knowledge of the effects of high water temperature may provide important information for producers on grow-out management, timing of production and farm location. Experiments were conducted to determine the effect of high water temperature on survival, moulting and food consumption in P. japonicus. Replicated groups of 15.6 +/- 0.2 g shrimp were acclimated and exposed to live temperatures, between 28 and 36 degreesC, for up to 28 days, Mortality was highest at 36 degreesC and equally lowest between 28 degreesC and 32 degreesC, Intermoult period was not significantly different for temperatures between 28 and 32 degreesC (19.8-15.5 days) but was significantly greater above 32 degreesC (27.4 days at 34 degreesC and > 104 days at 36 degreesC), There was evidence of moulting synchrony at 28 degreesC. Mean daily food consumption was highest at 32 degreesC at 2.34% of body weight, but decreased to 1.56% at 28 degreesC and 1.33% at 36 degreesC. Over the range of water temperatures examined, survival, moulting rate and food consumption were highest at 32 degreesC.