黑龙江省低额溞属的种类及分布（鳃足纲：双甲目）

本文对黑龙江省低额属Ｓｉｍｏｃｅｐｈａｌｕｓ的种类及分布进行了初步的调查。鉴定出低额９种，即锯顶低额Ｓｉｍｏｃｅｐｈａｌｕｓｓｅｒｒｕｌａｔｕｓ，老年低额Ｓ．ｖｅｔｕｌｕｓ，拟老年低额Ｓ．ｖｅｔｕｌｏｉｄｅｓ，棘爪低额Ｓ．ｅｘｓｆｉｎｏｓｕｓ，西伯利亚低额Ｓ．ｓｉｂｉｒｉｃｕｓ，角壳低额Ｓ．ｌｕｓａｔｉｃｕｓ，微齿低额Ｓ．ｈｉｍａｌａｙｅｎｓｉｓｍｉｃｒｏｄｕｓ，黑龙江低额Ｓ．ｈｅｉｌｏｎｇｊｔａｎｇｅｎｓｉｓ和北安低额Ｓ．ｂｅｉａｎｅｎｓｉｓ。对各种低额的形态特征及分布特点作了概括并编制了种的检索表。对所述各种的模式形态及已获种中雄体的精子形态提供活体照片。对部分低额生活环境中的几种主要因子进行了测试，其结果表明，本属各种多生活在水质清洁溶解氧较高且偏碱的水环境中，其水质多在寡污到β中污之间。

ON THE SPECIES AND DISTRIBUTION OF SIMOCEPHALUS IN HEILONGJIANG PROVINCE,CHINA (BRANCHIOPODA:DIPLOSTRACA)

Nine species of Simocephalus in Heilongjiang Province, China are described in the present paper. They are Simocephalus serrulatus, S. vetulus,S. vetuloides, S. exspinosus,S.sibiricus, S. lusaticus, S. himalayensis microdus, S. heilong jiangensis and S. beianensis.The specimens were collected from 275 freshwater points in 71 districts (Fig. 1)in Heilongjiang Prov.,China.All the species and the sperms of most species are photographed in living state. The keyto species of Simocephofus in Heilongjiang Province was made.Several main ecological factors were measured to Simocephalus and proved that thespecies of Siwrephalus have the habit of living in the alkaline water environment and theyare sensitive to water pollution. So the species of Simocephalus can be considered as one of the indicator animals to water pollution.