Unionicola

Unionicola is a genus of freshwater arachnids, specifically water mites, belonging to the family Unionicolidae.^[2][3] The genus was described in 1842 by Samuel Stehman Haldeman.^[1][2] The genus has cosmopolitan distribution.^[2]

Unionicola
Larva of Unionicola crassipes
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Trombidiformes
Family:	Unionicolidae
Genus:	Unionicola Haldeman, 1842[1]

Most Unionicola are associated with molluscs, but Unionicola crassipes and Unionicola minor are associated with sponges of family Spongillidae.^[4] The association with mussels can be described as symbiotic. There is evidence that mites consume host tissue^[5] and can be associated with reduced host fitness, although the causal direction of the latter remains unclear.^[6]

Species include the following:

• Unionicola gracilipalpis
• Unionicola figuralis
• Unionicola crassipes
• Unionicola aculeata
• Unionicola ypsilophora (Bonz, 1783)^[3]