Summary Freshwater snails serve as one of trematodes’ intermediate hosts. Previous studies on trematode larval stages in the Philippines have largely focused on species with public health importance. This study sought to investigate the prevalence of cercarial morphotypes in several freshwater snail species found in different habitat types (rice field, irrigation canals, and residential area) in selected agricultural areas in Los Baños and Bay in Laguna. Cercarial emergence was induced through exposure to artificial light. A total of 2,720 freshwater snails were collected and were represented by seven species, namely, Melanoides tuberculata Muller 1774 (n = 1229), Radix quadrasi von Moellendorf (n = 630), Tarebia granifera Lamarck, 1816 (n = 417), Pomacea canaliculata Lamarck 1819 (n = 257), Vivipara angularis philippinensis Nevill (n = 18), Stenomelania sp. (n = 104), Thiara scabra Muller 1774 (n = 65). A 2.57 % over-all prevalence was recorded; the infected snail species were M. tuberculata (2.21 %), R. quadrasi (0.21 %), T. granifera (0.11 %). Four cercarial morphotypes, namely, Parapleurolophocercous cercaria (1.80 %), Virgulate xiphidiocercaria (0.26 %), Megaluruous cercaria (0.29 %), and Echinostome cercaria (0.22 %) were recovered from the infected snail species. Prevalence of cercarial infection was significantly different (p < 0.05) among habitat types.

中文翻译：

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菲律宾拉古纳选定农业区的淡水蜗牛尾蚴

总结 淡水蜗牛是吸虫的中间宿主之一。以前对菲律宾吸虫幼虫阶段的研究主要集中在具有公共卫生重要性的物种上。本研究旨在调查在洛斯巴尼奥斯和拉古纳湾的选定农业区的不同栖息地类型（稻田、灌溉渠和住宅区）中发现的几种淡水蜗牛物种中尾蚴形态型的流行情况。通过暴露于人造光诱发尾蚴出现。共收集了 2,720 只淡水蜗牛，分为 7 个物种，即 Melanoides tuberculata Muller 1774 (n = 1229)、Radix quadrasi von Moellendorf (n = 630)、Tarebia granifera Lamarck, 1816 (n = 417)、Pomacea Lamarck 1819 (n = 257), Vivipara angularis philippinensis Nevill (n = 18), Stenomelania sp. (n = 104), Thiara scabra Muller 1774 (n = 65)。记录的总体流行率为 2.57%；受感染的蜗牛物种是 M.tuberculata (2.21 %)、R. quadrasi (0.21 %)、T. granifera (0.11 %)。从受感染的蜗牛物种中回收了四种尾蚴形态类型，即 Parapleurolophococous cercaria (1.80%)、Virgulate xiphidiocercaria (0.26%)、Megaluruous cercaria (0.29%) 和 Echinostome cercaria (0.22%)。不同栖息地类型的尾蚴感染率存在显着差异（p < 0.05）。从受感染的蜗牛物种中回收到巨型尾蚴 (0.29 %) 和棘口蚴尾蚴 (0.22 %)。不同栖息地类型的尾蚴感染率存在显着差异（p < 0.05）。从受感染的蜗牛物种中回收到巨型尾蚴 (0.29 %) 和棘口蚴尾蚴 (0.22 %)。不同栖息地类型的尾蚴感染率存在显着差异（p < 0.05）。