Download high resolution image here.

I raised this tiny creature from a dry soil sample collected and placed outdoors in a shallow tub of water on 12 APR 2018 from a vernal pool created by drainage from surounding roads and real estate at 35°3'6”N 106°35'5”W, 5249 ft, Albuquerque East 7.5’ quadrangle, Kirtland AFB, Bernalillo Co, NM. The date of record 03 MAY 2018 is when I collected and preserved the subject specimens.

In addition to this creature, Triops sp., Streptocephalus sp., and water fleas (Cladocera) appeared over the next 3 weeks. I originally guessed it might be a water flea hatchling since it somewhat resembles one, and its swimming behavior is very similiar. That is, it swims rapidly (for its size) in random directions, and darts away suddenly when disturbed. However, there appear to be eggs developing within its body, implying that it is an adult. It might be a remarkably small species of water flea. The images linked here are of different individuals from the same water sample displaying different perspectives for identification purposes. As to what those perspectives are (named in image title) is my best guess, based on the assumption that the eggs are in the posterior half and that the articulated projections seen in the images are swimming legs.

This specimen is slide mounted in Cargille immersion oil type OVH and darkfield 1.18-1.42 NA illuminated. This image is from a Helicon Focus processed stack of 123 images with a 0.4 µm step taken with a Nikon CFI Plan 50×/0.9 ∞/- mm oil microscope objective + Nikon 200 mm F4 AIS telephoto lens + Nikon D810 camera (magnification 50×; technique described here).