稻田网箱养殖辽河水系中华绒螯蟹幼蟹的个体生长

本实验在室外网箱内监测辽河水系中华绒螯蟹(Eriocheir sinensis)幼蟹阶段个体生长发育的每一次蜕壳生长情况。2013年实验选取雄蟹和雌蟹各200只,记录了每个蜕壳阶段雌蟹和雄蟹的生长,包括壳长、壳宽、总重和蜕壳间隔时长(d),并且观察雌蟹和雄蟹形态特征的变化。实验共进行111 d,幼蟹共蜕壳11次。实验结束时,雄蟹剩余34只,雌蟹剩余42只;雄蟹的特定生长率为(7.176 5±0.168 4)%/d,雌蟹的特定生长率为(7.283 3±0.174 3)%/d;雌蟹生长蜕壳过程中腹部的形态变化大,腹部由三角形变成卵圆形;雄蟹在生长蜕壳过程中螯足的增长明显较雌蟹快,并且在本实验最后一次即第11次蜕壳后螯足腹面内侧出现1小撮绒毛,外侧也出现少量绒毛,但不易被发现。

The Research of Individual Growth of Eriocheir sinensis for Liaohe Population Juvenile Crab in Paddy Field Net Cage

The molt times and morphological features changes of the Liaohe population Chinese mitten crab (Eriocheir sinensis ) were further explored. Molting and growth of juveniles of the Liaohe population Chinese mitten crab was studied in outdoor net cages by recording carapace width and length, body weight, molting frequency, and observing the changes of morphological features. Male and female crabs molt 11 times in the whole experiment stage. The experiment selected 200 male and female crabs respectively, and lasted for 111 days in 2014. Male and female crabs molted 11 times in the whole experiment. In the end, 34 male crabs and 42 female crabs survived. The Special Growth Rates of male and female crabs were 0.0989±0.0173g/d and 0.0951±0.0171g/d respectively. The abdominal morphological changes of female crab were very obvious in molt process, changing from triangle to ovoid (Fig.5). Chela-foot sufficient of male crab grew significantly faster than that of female crab. A handful fluff and a small amount of fluff appeared on the inside and outside of the chela-foot sufficient venter respectively after the eleventh molt (Fig. 6 and Fig. 7). The results show that molt times of Liaohe population Chinese mitten crab is likely to be 20 times and the time interval is changed by carapace width or carapace length index (Fig. 8) in whole life, in addition, some interesting phenomenon were observed.