Unionicola (Hexatax) tenuis (Lundblad, 1935)

Report associated with sponges: This species was mentioned under possible ‘sponge-mite’ species in North America (Vidrine 1996; Edwards & Vidrine 2013).

Remarks: This needs further study (emphasizing on developmental study) of this mite to get a better idea about its association with freshwater sponges. This species was reported from Haiti (Lundblad 1935), Oaxaca State, Mexico (Cook 1980), Guatemala (Viets 1975), and the Panama Canal Zone (Gliwicz & Biesiadka 1975). Viets (1975) suggests that Stoll's (1877) species may have been U. gracilipalpis tenuis .

Unionicola (Unionicola) gracilipalpis tenuis (Lundblad, 1935) reported by Vidrine et al. (1986) associated with sponges Dosilia radiospiculata from Louisiana, North America was kept under synonym of Unionicola (Unionicola) gracilipalpis in Vidrine (1996). Unionicola tenuis was reported in the mussel communities (Aufwuchs communities containing sponges) from Cajun Prairie ecosystem in Southwestern Louisiana, USA (Vidrine et al. 2004). Apparently, U. gracilipalpis and U. tenuis in Louisiana are not clearly separable (Vidrine, Personal communication).