MM159999

The Hygrobatidae is a family of water mites in the superfamily Hygrobatoidea. There are 17 genera and 74 species of hygrobatids in Australia, making it the biggest family of water mites on the continent. Unfortunately, the Hygrobatidae is difficult to diagnose at a familial level, and there are no generally accepted subfamilial categories (Harvey 1998). Hygrobatids show great morphological variation. Some species are lightly sclerotised while others have numerous dorsal sclerites or complete unitary dorsal plates. Some have swimming hairs while others lack them. The only unique morphological feature uniting the Hygrobatidae is the presence of a glandularium on coxa IV (which sometimes 'migrates' up to coxa III). This glandularium can only reliably be seen on cleared specimens under high magnification.

Genera of Australian hygrobatids are: Aspidiobatella (1 sp., NSW and other records from Qld (HCP)); Aspidiobates (8 spp., Qld, NSW, Vic, Tas, WA); Australiobates (12 spp., Qld, NSW, Vic, Tas, SA and other records from the NT (HCP)); Australorivacarus (3 spp., Vic, Tas and other records from NSW (HCP)); Caenobates (2 spp., Qld, NSW, Vic, Tas); Coaustraliobates (3 spp., Qld, NSW, Vic, Tas, NT); Cookabates (1 sp., NSW, Vic); Declinatobates (1 sp., Qld); Dropursa (3 spp., Qld, NSW, Vic, Tas); Gondwanabates (9 spp., QLD, NSW, Vic, Tas); Groonabates (1 sp., Tas); Hygrobates (2 spp., Qld); Kallimobates (3 spp., Qld, NSW, Vic, Tas); Procorticacarus (previouslyCorticacarus)(18 spp., Qld, NSW, Vic, Tas); Rhynchaustrobates (5 spp., NSW, Tas and a new record from Qld (HCP)); Tasmanobates (1 sp., Tas); Tobelobates (1 sp., Vic, Tas).

Hygrobatids are found in many different standing and running water habitats, but they are most diverse in surficial stream substrates.

References

Cook, D.R. 1986. Water mites from Australia. Mem. Amer. Ent. Inst. 40: 1-568.

Harvey, M.S. 1998. The Australian Water Mites: a Guide to Families and Genera. CSIRO Publishing, Collingwood, Vic.