1 症状与危害 瓣鳃纲中一些蚌类的钩介幼虫用长而具有粘性的足丝和钩子附着在鱼体上,通常在鱼的鳃、口、鳍条以及皮肤上。鱼体受到刺激引起周围组织发炎增生,色素渐消退,并逐渐将幼虫包围在里面,形成包囊。较大的鱼体寄生几十个钩介幼虫,一般影响不大,但对饲养5、6天的鱼苗和体长1. 1 Symptoms and Harms Some mussels in the gill-organizing ganglia larvae attach themselves to the fish body with long, sticky foots and hooks, usually on the gills, mouth, rays and skin of the fish. The fish are stimulated to cause inflammation of the surrounding tissue hyperplasia, the pigment gradually subsided, and gradually larvae surrounded by the formation of cysts. Larger fish parasites dozens of hook-mediated larvae, the general effect is not, but for feeding 5,6 days of fry and body length 1.