不同生境蚶形无齿蚌的形态观察

Morphological Observation on Anodonta arcaeformis in Different Habitats

对不同生境下蚶形无齿蚌壳的形态、育儿囊的类型和结构以及钩介幼虫等进行了比较研究。结果表明 ,在不同生境下 ,蚶形无齿蚌个体大小有很大差异 ,壳具有高度的可塑性 ;育儿囊由两片外鳃构成 ,为外鳃类的同生型 ,钩介幼虫在育儿囊内呈散乱状态存在 ;在不同区域 ,钩介幼虫的大小不同 ,但其壳高与壳长的比例却是一致的 ,且不同生境钩介幼虫的超微结构相同 。

In terms of shell shape, type and structure of marsupium and glochidial characters, a comparative study of Anodonta arcaeformis collected from different habitats was conducted. The results were as follows: The size of Anodonta arcaeformis differed greatly from different habitats. The shell had high plasticity. Its marsupia were composed by two exobranchiaes, so it was exobranchiaes homogenae. Glochidia distributed in marsupium with a state of chaos. Though glochidia in different regions were of different sizes, the ratio of height to lengh of the shell was coincident, and the glochidial ultrastructure under electron microscope were also coincident.