FFECTSOFTEMPERATUREANDCa^(2+)ONTHELARVALDEVELOPMENTOFTHEDECAPODACRUSTACE

EFFECTS OF TEMPERATURE AND Ca^( 2+) ON THE LARVAL DEVELOPMENT OF THE DECAPODA CRUSTACEAN: ERIOCHEIR SINENSIS

With increasing demand in China for the mitten crab larvae, understanding its survival mechanism gets more important. This research focused on the effects of temperature and Ca 2+ on the larval growth and development. Eriocheir sinensis larvae were reared in laboratory under 21 different combinations of temperature (15, 20, 25℃) and Ca 2+ content (120, 130, 140, 150, 160, 170, 180 mg/l) and constant salinity (20) and pH (8). The results suggested that the survival rate increases with temperature and Ca 2+ content. These combinations of temperature and Ca 2+ content maximized survival rate in our study and it may be the optimum water environmental conditions for culturing the larvae. To predict surviving larvae number under different water environmental conditions, 21 dynamic mathematical models were developed. This for the first time observation of the zoeal Ⅵ larvae of the Changjiang River E. sinensis population showed that they occurred under stressed water environmental conditions: temperature of 15℃ and Ca 2+ content of 120,130 mg/l.