从正面效应看,在100多种引进种中,已形成万吨以上养殖产量规模的有10来种(表1)。引进种在我国水产养殖总产量中的比例大约为10%。由于引进种中大多是名特优商品,故在我国水产养殖总产值中的比例约为20%。鱼类中的罗非鱼和大菱鲆、贝类中的扇贝,是引进后形成可观产业的典型代表? In terms of the positive effect, of the more than 100 introduced species, over 10 million species of aquaculture production have been formed (Table 1). The introduction of species in China’s total aquaculture production in the proportion of about 10%. Due to the fact that most of the introduced species are famous special commodities, the proportion of aquaculture output in China is about 20%. Fish in the tilapia and turbot, shellfish in the scallops, is introduced after the formation of a considerable representative of the industry?