中文摘要：

以5种裸腹溞Moina为试验材料进行了染色体数目和核型的研究。染色体制片采用气干法，依据Levan等和Stebbins的标准进行染色体分类。结果表明：蒙古裸腹溞M.mongolica的核型公式为2N=6M＋18T，NF=30，1A；多刺裸腹溞M.macrocopa，2N=10M＋12T，NF=32，1A；直额裸腹溞M.rectirostris，2N=12M＋12T，NF=36，1B；微型裸腹溞M.micrura，2N=10M＋14T，NF=34，1A；近亲裸腹溞M.affinis，2N=12M＋14T，NF=38，1B。在此基础上进一步探讨了5种裸腹溞的亲缘进化关系，认为5种裸腹溞按进化地位的高低顺序依次为直额裸腹溞〉近亲裸腹溞〉多刺裸腹溞〉微型裸腹溞〉蒙古裸腹溞。

英文摘要：

The chromosomal numbers and karyotypes of 5 species water fleas Moina were studied by the air - drying method. The chromosomes were classified by the methods of Levan et al. and Stebbins. The karyotype formula was found as following： 2N =24 =6M ＋ 18T, NF =30, 1A in M. mongolica; 2N =22 = 10M ＋ 12T, NF =32, 1A in M. macrocopa; 2N =24 = 12M ＋ 12T, NF =36, 1B in M. rectirostris; 2N =24 = 10M ＋ 14T, NF =34, 1A in M. micrura; 2N =26 = 12M ＋ 14T, NF = 38, 1B in M. affinis. Furthermore, the evolutionary relationship among 5 species of Moina was discussed, and the comparable result revealed that the phylogenetic status was descendantly arranged as the following： M. rectirostris 〉 M. affinis 〉 M. macrocopa 〉 M. micrura 〉 M. mongolica.