Records of aquatic oligochaetes (Annelida, Clitellata) from Lake Izunuma and Kabukurinuma Marsh, Miyagi Prefecture, northern Japan

Abstract

Based on new material collected in June 2008, twenty-five taxa of aquatic oligochaetes belonging to three families, Naididae, Tubificidae and Enchytraeidae, were recorded from Lake Izunuma and Kabukurinuma Marsh in Miyagi Prefecture, northern Japan. The records from L. Izunuma included the northernmost record of the tubificid Rhyacodrilus hiemalis. The offshore benthic oligochaete assemblage in L. Izunuma was dominated by Limnodrilus hoffmeisteri and devoid of Tubifex tubifex, and the composition resembled those of several other shallow and eutrophic lakes in Japan. A diverse naidid assemblage was found in the vegetated littoral L. Izunuma, and an oligochaete community of diverse ecological niches was found in Kabukurinuma Marsh, both of which could be associated with habitat characteristics. It is suggested that past records of two oligochaete species were erroneously identified.