Two new sympatric water-mites (Acari: Hydrachnidia: Unionicolidae) from the mutelid bivalve Aspatharia sinuata (von Martens) in Nigeria with some data on unionicoline-bivalve relationships.

Descriptions and figures of two new sympatric species of water-mites, Unionicola blayi and U. planicurvata, belonging to a new unionicoline subgenus, Mutelicola, found in the mutelid bivalve Aspatharia sinuata (von Martens, 1883) in Nigeria are presented. These are the first records of unionicoline 'parasites' of bivalves from Africa and the first records of unionicolines from mutelid mussels. Their occurrence in these freshwater bivalves is discussed and some data on unionicoline-bivalve relationships are also presented. [ABSTRACT FROM AUTHOR]