在目前的条件下,要做好鱼类病害的预防工作,(?)的同时,注重增强鱼体抵(?) 一、培育抗病力强的新品种或进行人工免疫 在鱼类饲养过程中,可见到一些发病严重的鱼池。大多数鱼患病死亡,而存活下来的鱼,往往都长得很好。这种现象表明,鱼体抗病能力与鱼的个体 Under the current conditions, we should do a good job in the prevention of fish diseases, (?) At the same time, pay attention to enhancing the arrival of fish (?) First, to cultivate new varieties of disease resistance or artificial immunity during fish feeding , You can see some serious fish pond. Most fish are sick and dead, and the surviving fish often grow well. This phenomenon suggests that the fish are resistant to disease and fish to individuals