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On this page we look at the ventral side and posterior side of the female specimens. As
described on the previous page, the mites have a somewhat
flattened body shape and are armored.
On the posterior side we see in the photos next to it something that looks like taillights.
These are two plates with three acetabula (cups) each. I don't know why they are so dark
on this specimen, but it gives a nice effect. In the photo on the left three green
micro-organisms (algae?) can be seen on one of the acetabular plates.
Below is a photo that gives a reasonable well impression of the ventral side and posterior of a female specimen. The posterior side has a notch, together with the two 'eyes' of the cup plates, it reminds me of an owl's head. At first glance we see only one of the acetabula per plate. When looking more carefully, the other two are visible under the covering armor. By holding the mouse arrow above the right photo, we see an indication of the acetabula (for tablets and phones: just tap).
In Brachypoda, the coxae (the 'hip plates') are fused to the abdominal armour. The 4th coxae (Cx-IV) are large and cover almost the entire abdomen in the female. The remaining coxae are fused into a group, with the pointed ends pointing forward and reaching the edge of the carapace. There is no medial suture between the coxae. In the example classification on this website, Brachypoda is traditionally placed in the subfamily Axonopsinae and I read that in Gerecke et al. (2016) as well. B. versicolor is the only species in Europe (Smit, 2018). There are genera that are very similar, for example Neobrachypoda, but they do not occur in the Netherlands or are (very) rare. Within the Axonopsinae, a number of monophyletic groups are distinguished, within which species are very similar (Gerecke et al., 2016 48-49).
Under water the structure of the armour with the pores is not clearly visible, for that the mite has to be viewed more or less dry. That does not produce nice pictures, but the structure is better visible in the pictures on the left.
The right photo also clearly shows that the acetabula have a certain height.
Finally, on the left, a somewhat larger photo of the underside. I had some trouble taking a clear photo of this little creature, the photo is not as sharp as I would like. It has been brightened up a bit, to make the details a bit more visible. Furthermore, this specimen is not so specifically square, see the photo below for comparison, that specimen does have the right angles at the front.
