Abstract: Objective　To investigate the population distribution of intermediate host snails and crabs of Paragonimus  along the Jiulongjiang River, Zhangjiang River, and Dongxi River basins in Bopingling Mountain, southern Fujian Province, so as to provide baseline data for researches on parasitic disease prevention and control and enlargement of samples in the parasitic resource bank. Methods　A total of 23 villages in 8 counties (districts) along the Jiulong River, Zhangjiang River, and Dongxi River basins in Zhangzhou City, Fujian Province were selected as survey sites during the period from November 2020 through March 2023, and snail and freshwater crabs were sampled from 1 to 3 streams and ditches neighboring residential areas in each village. Morphological identification of snails was performed according to the external morphological characteristics of collected snail shells, and the unidentified snail species sampled from the natural foci of paragonimiasis in Yunxiao County were subjected to sequence analysis of the mitochondrial cytochrome oxidase 1 (CO1) gene. The crab species was identified by observing the morphological characteristics of the terminal segment of the first pleopod of male crabs, and Paragonimus cercariae and metacercariae were detected in collected snails. Results　The shells of the unidentified snails sampled from the natural foci of paragonimiasis in Yunxiao County were approximately 50 mm in height and 18 mm in width, thick and solid, long tower cone⁃shaped, and had 8 to 10 whorls. CO1 gene sequence analysis identified the snail species as Sulcospira hainanensis. A total of 6 freshwater snail species belonging to 5 genera within 3 families, identified 23 survey sites, including Semisulcospira libertina, Paludomus zhangchouensis and S. hainanensis that belonged to the Family Pleurceridae, Tricula fujianensis and T. huaanensis that belonged to the subfamily Triculinae, Family Pomatiopsidae, and Melanoides tuberculata (Family Thiaridae), and 11 species of freshwater crabs belonging to 5 genera within 2 families were identified, including Sinopotamon  genus of S. jianglense, S. pinheense, and  S. zhangzhouense, Huananpotamon genus of H. planopodum and H. zhangzhouense, Nanhaipotamon genus of N. huaanense and  N. longhaiense, and Minpotamon genus of M. nasicum and M. auritum that belonged to the Family Potamidae, and Somanniathelphusa genus of S. huaanensis and S. zhangpuensis (Family Parathelphusidae). In addition, the prevalence of P. westermani cercariae infections was 0.08% (2/2 317) in P. zhangchouensis from Danyan Village in Changtai District and 0.09% (1/1 039) in S. hainanensis from Jinkeng Village in Yunxiao County, and the prevalence of P. westermani metacercariae infections was 25.81% (8/31) in S. jianglense from Danyan Village in Changtai District, and 26.31% (5/19) in S. zhangzhouense from Jinkeng Village in Yunxiao County, respectively.  Conclusions　There is a population diversity in the intermediate host snails and crabs along the Jiulongjiang River, Zhangjiang River, and Dongxi River basins in Bopingling Mountain, southern Fujian Province, and P. zhangzhouensis and S. hainanensis are, for the first time, confirmed as the first intermediate hosts of P. westermani.

Key words: Paragonimus, Paragonimus westermani, Intermediate host, Freshwater snail, Freshwater crab, Population diversity, Fujian Province

摘要： 目的　调查福建省南部博平岭山脉九龙江、漳江和东溪流域并殖吸虫中间宿主螺及蟹种群分布，为寄生虫病防治研究和寄生虫资源库样本扩充提供基础资料。方法　2020年11月—2023年3月，选择福建省漳州市境内九龙江、漳江和东溪流域8个县（区）23个村作为调查点，在每个村居民区附近选择1～3条山涧水沟采集螺、溪蟹标本。根据所采集标本螺壳外部形态特征进行形态学鉴定，并对采集自漳州市云霄县卫氏并殖吸虫病自然疫源地的待定螺种进行线粒体细胞色素氧化酶1（cytochrome oxidase 1，CO1）基因序列分析。观察雄蟹第一腹肢末节形态特征并进行蟹种分类，检测部分调查点螺并殖吸虫尾蚴、蟹并殖吸虫囊蚴感染情况。结果　采集自云霄县卫氏并殖吸虫病自然疫源地的待定螺种壳高逾50 mm、壳宽18 mm，壳质厚、坚固，外形呈长塔锥形，有8～10个螺层，经CO1基因序列分析鉴定为海南沟蜷螺。在23个调查点共查见淡水螺6种，隶属3科5属，包括黑贝螺科短沟蜷属放逸短沟蜷、沼蜷属漳州沼蜷、沟蜷属海南沟蜷，盖口螺科拟钉螺亚科拟钉螺属福建拟钉螺和华安拟钉螺，蜷科拟黑螺属瘤拟黑螺。共查见淡水蟹类11种，隶属两科5属，包括溪蟹科华溪属将乐华溪蟹、平和华溪蟹和漳州华溪蟹，华南溪蟹属平肢华南溪蟹和漳州华南溪蟹，南海溪蟹属华安南海溪蟹和龙海南海溪蟹，闽溪蟹属鼻肢闽溪蟹和耳肢闽溪蟹；束腹蟹科束腰蟹属华安束腰蟹和漳浦束腰蟹。漳州市长泰区丹岩村漳州沼蜷和云霄县金坑村海南沟蜷卫氏并殖吸虫尾蚴感染率分别为0.08%（2/2 317）和0.09%（1/1 039），长泰区丹岩村将乐华溪蟹和云霄县金坑村漳州华溪蟹卫氏并殖吸虫囊蚴感染率分别为25.81%（8/31）和26.31%（5/19）。结论　福建省南部九龙江、漳江和东溪流域并殖吸虫中间宿主螺、蟹具有种群多样性，首次证实漳州沼蜷和海南沟蜷可作为卫氏并殖吸虫第一中间宿主。 　

关键词: 并殖吸虫, 卫氏并殖吸虫, 中间宿主, 淡水螺, 溪蟹, 种群多样性, 福建省