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Hydrachna sp. On the left one of the nymphs of the accompanying pages in side view. Hydrachna species are spherical, but the ventral side is flattened, as in most water mites.
Below is a detail of the photo on the left. The arrow points to the development of the genital plates, which are somewhat convex.
Below is a picture of the underside of one of the specimens. The genitalia can be clearly seen. I do not know whether the structure can tell us anything about the species. Besseling (1964) writes about the nymph of H. cruenta: "The lateral edges of the cup plates lie over the proximal edges of the third and fourth epimeres." (Translated from Dutch). That description seems fit in this case. The shape of the shields above the eyes also looks a lot like the sketch by the same author. The frames he described around the cup plates and the continuation of the fourth epimeres: "... up to twice as wide as the anal shield, clearly asymmetrical in shape, the posterior edge convex." cannot be confirmed here. So a definite determination is not possible.
Above is a detail of the photo on the left. Move the mouse pointer over the photo to see a schematic indication of the genital predisposition.
Finally, a shot of the bottom of one of the specimens, viewed from more behind. The bulges are clearly visible due to the slanted position. Compare this photo with the photo on the top right of this page.
