Opilioacarida
a most unusual mite

The Opilioacaridae (Parasitiformes) are a rare and primitive single family of mites, usually found under stones and leaf litter, as well as some caves. They are widely distributed across the warm or tropical regions across the world although few species have so far been described. They have, as the name suggests, a certain Opiliones/Harvestmen feel about them. How unusual these animals are can be guessed by the fact that there is only one family, and so far, only around twelve genera in the entire order.

They are the only mites to have retained six eyes across most of the genera, as well as having a segmented abdomen, perhaps a throwback to some ancient arachnid-type ancestor. They are also brightly coloured, in stunning pinks and blues. Apart from the species found in caves, they all also have striped legs. Unlike other mites, they also continue to moult throughout their lives, enabling full regeneration of lost legs in just a few weeks. 

They are mainly fast moving scavengers, eating fungi and pollen although occasional predation on small arthropods has also been recorded in some species. Opilioacarids have been observed exhibiting some parenting behaviour, protecting the eggs and the subsequent non-eating larval and protonymph offspring.

Ma M Vázquez, D May, E Alamilla, H Klompen
A new species of Opilioacaridae (Parasitiformes: Opilioacarida) from Belize with some observations on life history and behavior

http://dx.doi.org/10.1603/AN13056