Population Genetics Analysis of a Snail (Gastropoda: Ampullariidae) in Thailand and its Low Infection by .

is a freshwater snail in family Ampullariidae that is native to South and Central America. This snail is among the more important intermediate hosts for and agricultural pests. Herein, we investigated the prevalence of larvae and the genetic diversity of samples collected across Thailand based on mitochondrial cytochrome oxidase subunit I () gene sequences. The larval-infection rate was 1.7% in specimens collected from the Uttaradit Province of northern Thailand. We randomly selected specimens of and for genetic analysis. We analyzed 244 sequences, including 49 sequences from samples collected from Thailand and a publicly accessible database of snails in their native and non-native ranges. A maximum-likelihood tree of and revealed two main clades. The genetic diversity analysis identified seven haplotypes and six haplotypes, and showed genetic differences between the populations of and . The haplotype networks of and populations in Thailand are similar to those of populations in multiple countries, indicating that this species spread widely to many parts of the world.