Depth and particle size were primary and secondary environment variables that influence the community structure of brachyuran crabs in the present geographic region.

深度与沙粒粒径大小，分别为影响调查区域内螃蟹群聚结构之主要与次要因素。

The change trend was influenced by several reasons such as the aquatic habitat, the ecological characteristics of fish, the community structure of digenetic trematodes and import of live fish.

这种变化趋势受多种因素的影响，即水环境特点、鱼类的生态习性、复殖吸虫的群落结构、活物运输等。