A comprehensive survey of larval digenean trematodes and their snail hosts in central Alberta, Canada.

Digenean trematode distributions, compatibility profiles with their snail hosts, and complete life cycles remain mysteries in many parts of the world. Surveys of digenean biology and ecology provide further insight and perspective into just how incredibly diverse and important helminth parasites are in shaping local ecosystems. Past surveys have provided substantial characterizations of adult digeneans within their definitive hosts, and many now have contributed toward furthering our understanding of larval digeneans within their intermediate host communities. However, much information about the diversity of digeneans and their relationships with their snail intermediate hosts are lacking in many locations across the globe. This is certainly true in Canada, where few records related to digenean-snail relationships exist. Currently, there is a need for more information about the presence and distribution of digeneans across Canada, and how this compares to other parts of North America and beyond. To address this diversity gap in Western Canada, six lakes within central Alberta were surveyed for the presence of snails and larval digenean species and their associations. This investigation into the diversity of digeneans utilized a combined approach of morphological and molecular tools to identify 39 digenean species among five snail host species, from biweekly collections, taken over the course of 2 years (2013-2014). Here, digenean-snail combinations, presence, and distribution across sampling sites and lakes are reported. Overall, this survey contributes new information toward digenean-snail compatibility, life cycles, and distribution in Northern lake ecosystems within North America.