Effects of water temperature on growth, feeding and molting of juvenile Chinese mitten crab Eriocheir sinensis

Chinese mitten crab (Eriocheir sinensis) juveniles (0.06-0.15 g) were individually reared at four temperatures (18, 22, ambient temperature and 30 degrees C) for 35 days. Each treatment (36 replicates per treatment) was conducted in temperature controlled recirculating rearing systems, and the four systems were randomly placed in a room subjected to natural light condition. The food intake, inter-molt period (IP), and molt increment (MI) were determined for each crab. After 35 days, all crabs reared at 18 degrees C survived, whereas the survival of the other groups was at 97.2%. Animals at 28 and 30 T grew significantly faster (P < 0.05) than those reared at 18 and 22 degrees C. The first inter-molt period in E. sinensis was significantly shortened with increasing temperature (P < 0.05). The IP of C5-C8 (the fifth to eighth molting stage started from megalopa) was about 9-18 days. The percentage of MI decreased with body weight, but was not correlated to water temperature. Daily food intake increased notably with temperature and body weight (P < 0.05). The percentages of daily food intake in relation to body weight were 2.9%, 3.5%, 5.4% and 5.6% at 18, 22, 28 and 30 T, respectively. Maximum feed conversion efficiency (FCE) occurred at 22 degrees C (54.5%), which was significantly higher than that at 28 degrees C (43.6%) (P < 0.05). In conclusion, 28-30 degrees C is the optimal water temperature for the growth and molting of juvenile Chinese mitten crab. Statement of relevance: Chinese mitten crab (Eriocheir sinensis) is a native crustacean that play an important role in Chinese aquaculture. In general, there is a paucity of research on mitten crab culture technology, especially a dearth in the estimation of technical parameters for effective farming. In addition, there is very little known on the growth characteristics (Inter-molt period and Molt increment) and feeding efficiency of early juvenile stages of E. sinensis in relation to temperature. The present study attempts to understand what effects of water temperature on growth, feeding and molting of E sinensis, based on crabs reared individually in a temperature controlled system. (C) 2016 Elsevier B.V. All rights reserved.