FRESH-WATER SPONGES (PORIFERA, SPONGILLIDAE) OF EASTERN CANADA - TAXONOMY, DISTRIBUTION, AND ECOLOGY

During a recent survey of the freshwater sponges of eastern Canada (from Ontario to Newfoundland), 15 species were recorded, representing approximately 50% of the total number of species known from North America. Radiospongilla crateriformis, Spongilla aspinosa, and Trochospongilla horrida are reported from Canada for the first time. Two problematic species, Corvospongilla novaeterrae and Spongilla johanseni, are reviewed and their status is revised. Detailed notes on taxonomy, morphology, distribution, and ecology are given. New limits of tolerance with respect to pH, water temperature, and calcium and magnesium concentrations are established for several species. A taxonomic key to the freshwater sponges of eastern Canada is presented.