当池水受重金属等污染时,可引起虾、蟹的幼体发生烂肢以及引起蟹的步足断落;在换水时,虹吸管的吸力太大,或管口接近网箱壁,将虾、蟹的幼体吸在网箱上撞伤或在搬运时撞伤,也可引起烂肢。患烂肢病的幼体附肢从远端开始腐烂,甲壳皱缩,尾刚毛从基部烂掉;镜检腐烂处一般无病原生物寄生,仅个别患病幼体在后期有继发细菌感染,污染较严重时可引起全池幼体死亡。患断肢病的蟹,步足在基节与座节的 When the water is polluted by heavy metals, can cause shrimp, crab larvae and the foot caused by crabs off; in the water change, siphon suction too much, or nozzle close to the cage wall, the shrimp, crab The juveniles inhabit the cages and bruise or bruise while handling, can also cause bad limbs. The larvae with limbs of ill patients started to decay from the distal end, the crusts shrank and the tails of the capitals roted from the base. The pathogeny showed no pathogen parasitism at all, and only some of the affected larvae had secondary bacterial infection later in the test. Severe cases can cause death of whole pond larvae. Crab limb amputation, foot in the base section and seat section