Freshwater sponges in Lake Izunuma-Uchinuma

Abstract

Freshwater sponges were collected from five sites in the water near the edge of the Lake Izunuma-Uchinuma and were identified based on the morphology of spicules. Although this investigation was carried out to make a search for Ephydatia fluviatilis and not a comprehensive survey of sponge species, we found three species of freshwater sponges: Eunapius fragilis, Ephydatia muelleri, and Spongilla lacustris. This report made the first record of sponges from Lake Izunuma and Uchinuma since about 75 years ago and Eunapius fragilis was newly recorded from these lakes.