许多地方驯养育成的鱼种规格大小不一、相差悬殊,这会影响养殖成品的规格整齐和市场销售,也会带来经济效益不佳。造成这种现象的主要原因有以下几点:1放养的鱼苗规格不齐放养鱼苗本身的规格不齐是造成鱼种规格不齐的主要原因之一,因为大小不一的鱼苗群体往往强弱较明显,强的不但适应快、开食早,挑食能力也强。而且这种现象会随着养殖时间延长日趋明显,最后育成的鱼种规格必然不齐。2放养时间不统一虽然放养鱼苗的规格都很整齐,但如果不是同批苗同时放养,也会造成鱼种的规格不齐。这是因为鱼类在鱼苗阶段生长速度最快,特别是驯化的鱼,几乎是一天一个样,放养晚的自然跟不上放 In many places, the sizes of fish species raised and raised by domesticated animals vary widely in size, which can affect the neatness and marketability of finished fish products and lead to poor economic returns. The main reasons for this phenomenon are the following: 1 stocking different specifications of fry stocking different specifications of the fish itself is one of the main reasons for the different specifications of fish species, because fry groups of different sizes tend to be more strength and weakness Obviously, not only to adapt to fast, early morning meal, picky eaters are also strong. And this phenomenon will become increasingly evident with the extension of farming time, the final bred fish species specifications inevitable. 2 stocking time is not uniform Although the stocking specifications are neat fish neat, but if not the same batch of stocking, can also cause the fish species specifications are not homogeneous. This is because fish grow fastest in the fry stage, especially domestication of fish, almost day after day, stocking late nature can not keep up