现在又到了幼蟹放养的季节,养蟹户在选购幼蟹时,要防止购进2龄“小老蟹”,由于河蟹的寿命一般仅2年。2龄幼蟹放养后到春、夏季即会死亡,成蟹回捕率很低。怎样区分1、2龄幼蟹呢?大致可参考以下五个方面区分:(1)头胸部:1龄蟹的甲沟纹理较低,2龄蟹则较深而清晰。(2)颜色:1龄蟹壳背绿 Now go back to the stocking season of crabs, crab households in the purchase of crabs, to prevent the purchase of 2 “old crabs”, crabs due to the general life expectancy is only 2 years. 2-year-old crab stocking to spring, summer will die, crabs back to capture a very low rate. How to distinguish between the first and second instar larvae? It can be roughly divided into the following five areas: (1) head and chest: the crab at the first instar lower crab texture, while the second crab is deeper and clear. (2) Color: 1 year old crab shell back green