SPONGILLA-HETEROSCLERIFERA SMITH, 1918 IS AN INTERSPECIFIC FRESH-WATER SPONGE MIXTURE (PORIFERA, SPONGILLIDAE)

A freshwater sponge classified as Spongilla heterosclerifera Smith, 1918 and reported only from Oneida Lake, New York, was considered to be an endangered species. Examination of the holotype specimen reveals that it is actually an interspecific mixture of two widely distributed sponges, Ephydatia muelleri (Lieberkuhn) and Eunapius fragilis (Leidy). Spongilla heterosclerifera is therefore a junior synonym, in part, of both of these distinct species. Similar erroneous taxonomic interpretations of species mixtures have been documented and illustrate the importance of recognizing the possibility of species mixing when identifying freshwater sponge taxa.