几种理化因子对梅氏新本尼登虫卵发育的影响

Effects of several physical and chemical factors on eggs development of Neobenedenia melleni

观察在不同的水温、盐度、酸碱度条件下梅氏新本尼登虫（Neobenedenia melleni）卵发育以及毛蚴孵出的变化，以研究理化条件对卵发育的影响。结果表明，18～29℃之间，梅氏新本尼登虫虫卵的发育和孵化速度随温度的升高而加快，水温〈18℃或〉33℃发育停滞；盐度〈13．7虫卵不发育，盐度〈22．9或〉44．3卵发育停滞在眼点期，盐度居22．9～44．3之间，其改变对虫卵发育没有显著影响；酸碱度变化对虫卵发育没有明显的影响，pH为5．5或9．5时，卵均可正常发育并孵化，但孵化出的纤毛幼虫在pH〈6、0或〉9．0时，存活时间和活力明显降低。

Neobenedenia melleni （Menogenea：Capsalidae） is one of the most important pathogens of the marine net-cage culture fishes, it has a low host specificity and wide distribntion, and shucks on the gill and skin on fish, causing a high mortality among host fish. The adults lay hundreds of eggs that twin round the net or sundries in sea-water, it will be hatched 5-7 days later, and than attack on the fishes again. Large number of eggs collected and fell individually on culture vessels. The eggs were incubated at sea-water under different temperatures, different salinities and different pH values. The results showed that between 18 -29℃, the higher the temperature, the faster the development of the eggs. Over 33℃ or under 18℃ the development stops. The development of the eggs was stopped under salinity of 13.7 and it stops at the stage of eyed-egg both salinities 〈 22.9 or 〉 44.3. The influence of pH was no so obvious. The eggs developed well and hatched at either pH 5.5 or pH 9.5, but the survive time and activity of the hatched ciliary larvas are obviously lowering when pH 〈 6.0 or 〉 9.0. It was shown that the egg＇s shell can be against the influence of changing pH.