Neodiplostomum seoulensis n. comb. (Trematoda: Neodiplostomidae).

Fibricola seoulensis Seo, Rim, and Lee, 1964 was described from rats in Seoul, Korea and was later found to be a natural parasite in the intestine of humans. At the time this species was described, the classification of this and other strigeiform flukes was based largely on the phylogeny of the host; those adult worms parasitic in birds were placed in Neodiplostomum and those parasitic in mammals were placed in Fibricola. A recent analysis of this group produced a classification that was based on the phylogeny of the worms themselves and suggested that certain metacercarial and adult characters were more important in determining the phylogenetic position of these worms than was the host. In light of the new classification, we examined newly collected metacercariae and re-examined fixed adults of F. seoulensis and found their characters to be more compatible with the genus Neodiplostomum. The characters included a neodiplostomulum metacercaria with 4 transverse commissures and an adult stage with symmetrical anterior testis and vitellaria in both the fore- and hindbody. Therefore, it is recommended that F. seoulensis be recombined as Neodiplostomum seoulensis.