田螺科五种螺的核型研究

以早期胚胎细胞为材料,用火焰干燥法制片,对分布于我国湖北省武汉市近郊的常见田螺科(Viviparidae)五种螺的核型进行了分析。结果:两种圆田螺的染色体数和国外报道的同一属的种类的一致。而三种环棱螺的染色体数,则较国外报道的另两种的少得多。在铜锈环棱螺的核型中,其m组的第一对和sm组的第四对染色体上,具有明显的随体,出现频率甚高。

THE KARYOTYPE OF FIVE SPECIES OF FRESHWATER SNAILS OF THE FAMILY VIVIPARIDAE

The karyotypes of five species of fresh water snails were studied. These snails belonging to the subfamily Bellamyinae of Viviparidae were collected in the suburbs of the city of Wuhan, Hubei province, China.The chromosomes were prepared from the cells of the early embryos, of which the shell has not yet been developed , by flamedrying method.The karyotypes of both Cipangopaludina chinesis (Gray) and C. cathayensis (Heude) are the same as 2n = 18, 10m+6sm+2st, NF34. The diploid chromosome number of these two species showed no difference from other species of the same genus so far reported. The karyo-type of three Bellamya species, Bellamya quadrata (Benson), B. angularisa (Muller) and B. acruginosa (Reeve) are much alike as 2n = 16, 4m+8sm + 4st, NF28. except that B. aerugi-nosa is characterized by two pairs of the chromosomes m and sm, each with a secondary constriction and satellite frequently on the short arms. The diploid chromosome number of the three Bellamya species is much less than that of two Indian species of the same genus previously described. The morphological features between the individuals of Bellamya quadrata-collected from the south-lake population and from the east-lake population are much different. However, no apparent difference in their karyotypes has ken found.