Two Aquatic Oligochaete Species, Dero dorsalis and Allonais pectinata (Annelida: Clitellata: Naididae), New to Korea

The genera Dero and Allonais belong to the family Naididae. Most species in the genus Dero have unique morphological characters including a branchial fossa and/or gills at the posterior end of the body. The genus Allonais has no eyes unlike its close relative the genus Nais. Of these genera, one species of Dero, D. obtusa, was recently reported in Korea. However, the genus Allonais has not been recorded in Korea. Here, we report Dero dorsalis Ferroniere, 1899 and Allonais pectinata (Stephenson, 1910) with a diagnosis and illustrations.