申请人等对近溪蟹属等淡水蟹类的分子亲缘初步分析提示，雅鲁藏布江大峡谷缝合带所属河谷热带雨林和亚热带季雨林地域，可能存在多个淡水蟹类属、种的分布和为并殖吸虫第二中间宿主令业界瞩目。基于申请人等在雅鲁藏布江大峡谷墨脱县和与之相似生态地域的横断山脉与云贵高原地域采获215个样点淡水蟹类及其在研NSFC项目工作基础，本项目融合分子遗传学、甲壳动物学和寄生虫学等技术与方法，在建立形态学标本数据库基础上（与模式标本比对）对该地域淡水蟹类进行基因序列测定，并由此构建系统发育树和种群基因数据库。本项目的理论价值与科学意义，系在分子水平上追溯和揭示淡水蟹类的种群分化进程、多样性、分布格局及形成机制和作为分类上"属"的分化中心地位，探究大峡谷地域这一世界特殊生态地理区域淡水蟹类/并殖吸虫的动物地理模式在亚洲乃至世界淡水蟹类总分布格局中所处的地位与影响，并为其生物多样性的形成、演变与保护提供第一手基础数据资料。

Our initial molecular phylogenetic analysis of freshwater crabs (including Potamiscus) indicates that there might be multiple freshwater crab genera/species served as second intermediate host of paragonimus in the Brahmaputra Grand Canyon Suture Belt, drawing the attention of the world. We have collected freshwater crab samples from 215 distinct spots in Motuo County in Brahmaputra Grand Canyon and places with similar geobiological characteristics, supported by our current NSFC grants. By using techniques and methodologies of molecular genetics, crustacean zoology, parasitology and etc, we will build a morphological database (comparing with holotypes) of freshwater crabs in this area and perform genetic sequencing on collected samples. Then we will set up the phylogenetic tree and species genetic database based on the acquired data. This research will reveal the differentiation process, biological diversity, geographical distribution pattern of freshwater crabs and the underlying mechanisms, as well as the role as the origin of "genus" differentiation. We will explore, in the Grand Canyon, a unique biogeographical area in the world, the zoogeographical pattern of freshwater crabs and paragonimus, in parallel with its role in the overall zoogeographical pattern of freshwater crabs in Asia and even the world. We will provide the first-hand basic data for analyzing the formation of biological diversity, evolution and protection of freshwater crabs.