The results show that the densities of D-larvae and umho-larvae in Jiaozhou Bay have two peaks in one year.The density of the larvae in spring is higher than that in autumn.

• 结果表明：调查海区D形幼虫与壳顶幼虫密度全年呈双峰分布，春季繁殖期密度高于秋季，但总量较低；