嵊山列岛贻贝养殖种类生长发育调查

嵊山列岛贻贝养殖种类有紫贻贝、厚壳贻贝，对其的贝壳生长、体重增长、性腺发育的调查研究结果表明：1．与紫贻贝相比，厚壳贻贝生长缓慢，体长4cm以前，很难区分雌雄，9cm以前大部分显示为雄性，少量雌性，长到10cm后雌性才明显显示；2．同样个体大小的贻贝，厚壳贻贝的体重要大于紫贻贝，前期紫贻贝壳长快，厚壳贻贝壳长慢，但相比之下，后者体重增加比前者快；3．厚壳贻贝不同年龄的长势对比表明，通常年龄越大，体积的生长递增率越小，如第2年体积递增率为91．48％，到第3年则下降到49．23％，体重的生长递增率也随年龄增大而下降，如第2年体重递增率为44．83％，到第3年则下降到21．43％。最后还就该养殖渔区出现的“杂交贻贝”情况进行了讨论。

Mussel Species and Growth Developing Investigation around Shengshan Archipelago

There existed Mytilus coruscus,Mytilus edulis in Shengshan archipelago.An investigation of its growth,weight growth and gonad developing shows that:1.Mytilus coruscus grows slowly than Mytilus edulis.It is difficult to differentiate the sex below 4 cm in length.The male ones are dominant below 9 cm,then the female proportion increases obviously when growing to more than 10 cm.2.The Mytilus coruscus weighs more than Mytilus edulis,though having the same size.In prophase,the Mytilus edulis grow faster than Mytilus coruscus,but inverse on weight.3.The contrast of Mytilus coruscus growth with different ages shows that the older the age,the less the rate of growth for size,for instance, as 91.48 %of first year and 49.23 %in third year,the weight rateas 44.83 %in first year and 21.43 %in second year.Finally,the cross-bred mussel occuring in this area was described and discussed.