中华绒螯蟹生殖群体生物学特征及消化酶活力研究

为研究中华绒螯蟹生殖洄游途中渔获规格、性腺成熟度及消化能力的差异特征,于2014年洄游汛期内(10—11月)在长江下游8个断面采集样本并进行生物学调查及消化酶活力测定。共随机采集样本261只,其中雌蟹127只、雄蟹134只。壳宽变幅为44. 46～96. 06 mm,均值为(64. 28±9. 45) mm;体质量变幅为34. 9～312. 9 g,均值为(131. 65±57. 79) g。壳宽和体质量呈显著的幂函数相关,雌蟹关系式为y=0. 000 8x~(2. 859 6)(R~2=0. 951 2),雄蟹关系式为y=0. 000 4x~(3. 031 5)(R~2=0. 960 1)。性腺指数(GSI)变幅为0. 71～10. 84,均值为4. 94±2. 59;肝胰腺指数(HSI)变幅为2. 46～20. 04,均值为7. 92±1. 89。淀粉酶比活力变幅为0. 02～5. 45 U/mg prot,均值为(0. 84±0. 76) U/mg prot;脂肪酶比活力变幅为0. 28～1. 13 U/g prot,均值为(0. 68±0. 14) U/g prot;胰蛋白酶活力变幅为117. 21～78 897. 26 U/mg prot,均值为(10 947. 64±12 663. 57)U/mg prot;纤维素酶比活力变幅为0. 74～2. 59 U/g prot,均值为(1. 32±0. 27) U/g prot。结果表明,中华绒螯蟹洄游途中较少摄食,洄游早期主要由肝胰腺中贮备的脂肪供能,后期摄食强度则逐渐增大。在其生殖洄游通道上,渔获规格呈递减趋势,且雄蟹总体大于雌蟹;肝胰腺指数与性腺指数表现为消长的变化特征;淀粉酶和胰蛋白酶活力呈递降趋势,纤维素酶活性变幅较小,而脂肪酶活性则逐渐上升。

Comparative study on the biological characteristics and digestive enzymes activities of Chinese mitten crab (Eriocheir sinensis) during the reproductive migratory period

In order to study the characteristics of the differences in the catch specifications, gonad maturity and digestive ability of Eriocheir sinensis during the reproductive migration, samples were collected from 8 sections in the lower reaches of theYangtze River during the migration flood season from October to November 2014, and the biological investigation and digestive enzyme activity were carried out. A total of 261 samples were randomly collected, including 127 female crabs and 134 male crabs. The variation of shell width is 44.46-96.06 mm, with a mean value of (64.28 ±9.45) mm, and the body mass variation is 34.9 -312.9 g, with a mean value of (131.65 ±57.79) g. There was a significant power function correlation between shell width and body weight. The female crab relationship was y=0.000 8x^{2.859 6} (R²=0.9512), and the male crab relationship was y=0.000 4x^{3.031 5}(R²=0.960 1). The variation of gonad index (GSI) was 0.71-10.84,the mean value was 4.94 ±2.59, and the hepatopancreatic index (HSI) was 2.46-20.04,with a mean value of 7.92 ±1.89. The ratio of amylase to activity was 0.02-5.45 U/mg prot, the mean value was (0.84 ±0.76) U/mg prot, and the ratio of lipase to activity was 0.28-1.13 U/g prot, the mean value was (0.68 ±0.14) U/g prot. The activity of trypsin was changed to 117.21-78 897.26 U/mg prot, the mean value was (10 947.64 ±12 663.57) U/mg prot, and the cellulase activity was 0.74-2.59 U/g prot, the mean value was (1.32 ±0.27) U/g prot. The results showed that Eriocheir sinensis had less feeding during migration,the early stage of migration was mainly supplied by the fat stored in the hepatopancreas, while the later feeding intensity gradually increased. On the reproductive migration channel, the size of the adult crabs decreased along the river, and the male crab was generally larger than the female crabs. The hepatopancreas index and the gonadal index showed the variation characteristics, the activity of amylase and trypsin decreased and the activity of cellulase was smaller, but the activity of lipase increased gradually.