钉螺齿舌的光学显微镜与扫描电镜的观察

STUDY ON THE LIGHT MICROSCOPY AND SCANNING ELECTRON MICROSCOPY OF RADULAE OF ONCOMELANIA SNAILS

采集云南、四川、广西、福建、浙江5个省、自治区的光壳钉螺和湖南、湖北、江西、安徽、江苏、上海等6个省、市的肋壳钉螺。从每个地区钉螺的优势群中抽样解剖5～10个钉螺,结果表明,光壳钉螺齿舌带的长、宽度均略小于肋壳钉螺,而齿片的横列数却多于肋壳钉螺。各地钉螺或同一钉螺的齿舌公式虽有差异,但有一定的规律性,即具有常见的齿舌公式。例如肋壳钉螺的中央齿公式以(1-1-1)/(3-3)为主,占66.7％,而在光壳钉螺中,(1-1-1)/(3-3)和(2-1-2)/(3-3)各占40％。这些观察结果可作为钉螺分类的参考。

The radulae of snails collected from selected endemic areas in 11 provinces, municipalities and autonomous regions were studied. The results showed that the most commenly encountered radular pattern was observed in these specimens. In the majority of 'rough type' snails (shell with obvious ribs) from six swamp and lake regions and plain regions with net work of water courses the most commonly encountered formula of rachidian plate was 1-1-1/3-3 (66. 7%), but 1-1-1/2-2 also occurred (33. 3%); the most commonly encountered pattern of lateral plate was 2-1-3 (83. 3%). the number of cusps of inner and outer marginal plate were 7 (66. 7%) and 5 (50. 0%) respectively. In the 'smooth type' snails (shell without obvious ribs) from five mountainous and hilly regions, the most commonly encountered formula of rachidian plate was1-1-/3-3(40.0%) or 2-1-2/3-3 (40. 0%), and that of lateral plate was 2 - 1 - 3 (80. 0%), the numbers of cusps of inner and outer marginal plate were 7 (8) (40. 0%) and 5 (80. 0%) respectively. The average length of radular ribbons was 1.175 ± 0.156 (0. 96 - 1. 34) mm and the average width 0. 173 ± 0. 022 (0. 13 - 0. 20) mm. No apparent difference in size of ribbon was found between the rough type and smooth type.