Unionicola (Hexatax) crassipes (Müller, 1776)

Chatterjee, Tapas, 2021, A checklist of halacarid and hydrachnid mites (Acari, Halacaridae & Hydrachnidia) associated with sponges (Porifera), Zootaxa 5072 (2), pp. 101-129 : 114

Unionicola (Hexatax) crassipes (Müller, 1776)

Report associated with sponges: This species was reported among sponges of the family Spongillidae : Radiospongilla cerebellata (= Spongilla biseriata ), Spongilla lacustris , S. fragilis , Ephydatia fluviatilis , E. mülleri , Trochospongilla horrida from Europe (Arndt & Viets 1938, Conroy 1979; Hevers 1975, 1977, 1978, 1979, 1980).

Remarks: Böttger (1972) identified larvae of U. crassipes from Germany and summarised the life cycle. A description of the annual cycles of U. crassipes and U. minor was given by Davids et al. (1979) collecting samples in the field and by breeding different stages from sponge materials of Netherlands.

Unionicola crassipes reported from various places requires study with molecular sequencing to know the exact nature of the species. Some records may be due to a mixture of misidentification and species lumping. Many members of the ‘ U. crassipes- complex’ are treated here under U. crassipes . However, molecular analyses are becoming more frequent and should reveal the nature of the species in the complex. For example, molecular analysis of these water mites based on materials from Sweden was done by Stalstedt et al. (2013), where they found U. minor as a valid species and distinct from U. crassipes . Also, U. crassipes used in their molecular study was actually U. laurentiana ( Edwards et al. 2010) .