Molecular studies have shown that Platyhelminthes is polyphyletic, placing Rhabditophora within Lophotrochozoa, whereas Acoela and Nemertodermatida are separate early bilaterian branches. However, there has been little evidence to support the position

Specimens of Catenulida were collected at 34 localities in Sweden. We used 18S rDNA, 28S rDNA, ITS-5.8S, and cytochrome oxidase I (COI) nucleotide sequences to infer phylogeny from parsimony jackknifing and Bayesian analysis. Our dataset contained 74

Microturbellarians, small free-living Platyhelminthes are rich in freshwater environments. They are useful as indicator of water quality. There has never been a record of microturbellarians in Korea. Here I report a microturbellarian species, Catenula