Knowledge Bank

The sponge-associated Hydracarina of North America historically have been considered conspecific with the European species Unionicola crassipes (Miiller 1776). Ratio diagrams based on numerous morphological characteristics distinguish the North American crassipes-like mites from U. crassipes and two North American species are described. Unionicola laurentiana, n.sp., occurs in the Laurentian Great Lakes and St. Lawrence River basins. U. nearctica, n.sp., occurs in that region and its range extends across Canada from Ontario to British Columbia.