Unionicola (Hexatax) niigata Imamura, 1954

Report associated with sponges: This species was mentioned under ‘sponge-mite’ from Japan by Crowell (1990) referring Havers (1984). Edwards & Vidrine (2013) also mentioned the species under ‘sponge-mite’.

Remarks: This species belongs to the ‘ U. crassipes —complex’ and earlier authors (mentioned above) kept it under possible ‘sponge-mite’ species. It needs further study (emphasizing developmental study) to get a better idea about its association with freshwater sponges.