三种鲫鱼对暴发性鱼病的抗病力

本文报道彭泽鲫、异育银鲫及白鲫对嗜水气单胞菌引起的暴发性鱼病抗病力的研究结果。在菌液浓度为6.0×10~6个/ml,注射剂量为0.3ml/尾时,半数致死量(LD_(50))分别为彭泽鲫 10~(-1.?),异育银鲫 10~(-1.61),白鲫 10~(-2.21),差异极显著(P<0.01)。从三个方面进一步研究了造成以上差异的机理:(1)补体总量——彭泽鲫 6.40 单位/ml,异育银鲫 5.97 单位/ml,白鲫 2.20 单位/ml,差异极显著(P<0.01);(2)补体替代途径(C_d 旁路)杀菌能力——彭泽鲫和异育银鲫极显著优于白鲫(均值多重分析 D>D_(0.01)),彭泽鲫好于异育银鲫,但差异不显著;(3)白细胞吞噬功能——三种鲫鱼间存在极显著差异(P<.01),吞噬百分率是彭泽鲫极显著优于白鲫和异育银鲫(D> D_(0.01)),吞噬指数是彭泽鲫和异育银鲫显著优于白鲫(D>D_(0.05))。彭泽鲫是对暴发性鱼病抗病力较强的品种,白鲫是对暴发性鱼病抗病力最差的品种。

RESISTANCE OF THREE STRAINS OF CRUCIAN CARPS TO THE OUTBREAK-FISH-DISEASE

A study of resistance of three strains of crucian carp (Pengzhecrucian carp, allogynogenetic crucian carp and white crucian carp) to the outbreak-fish-disease was conducted. When the concentration of the diseases eaused bacte-ria-Aeromonas hydrophila was 6.0×10~8 ind./ml, injection dosage was 0.3 ml/fish,the median lethal dose (LD_(50)) for Pengzhe fish was 10~(-1.54), allogynogenetic fishwas 10~(-1.61), white fish was 10~(2.21), the differences were high significant (P0.01). The mechanism of resistance was studied from three sides: (1) The totalamount of camplements-the observed value in Pengzhe fish was 6.40 unit/ml,allo-gynogenetic fish was 5.97 unit/ml, white fish was 2.20 unit/ml, the differencewas highly significant. (2) Bactericidal reaction by the alternative pathway ofcomplement(C_3 shunt)-- Pengzhe and allogynogenetic were better than white highlysignificant (multiple mean comparison, DD_(0.01)). Pengzhe fish better than allo-gynogenetic fish, but not significant. (3) Leukocyte phagocytic function-therewere a high significand difference among the 3 crucian carps (P0 .01). In thephagocytic percentage, Pengzhe fish better than white and allogynogenetic fishhighly significant (DD_(0.01)), in the phagocytic index,the Pengzhe and allogyno-genetic fish better than white significantly (DD_(0.05)). Pengzhe fish is the betterstrain with high resistance to the outbreak-fish-disease, white fish is the worst.