Freshwater Ostracod Portland/ Crystal Springs Rhododendron Gardens, Multnomah County, Oregon, USA November 28, 2014 Size: About .8 mm
As far as I can figure out, this fellow belongs in the sub-class Podocopa, the order Podocopida, the sub-order Cypridocopina, the super-family Cypridoidea, and a few things below that that I'm having difficulty figuring out. Podocopa contains the only freshwater ostracods, as does Podocopida. I really don't think that this belongs in the sub-order Darwinulocopina (there's only one species option in the United States, but it's much more rectangular and lacks the striping and coloration of this ostracod), and my only other freshwater option is Cypridocopina. Cypridoidea is the only freshwater option in Cypridocopina, which makes me really appreciate how many marine ostracods there are. After that it gets tricky, and I would want to dissect a specimen before going further.
It really looks like one of the most common species of ostracoda on the planet, Cypridopsis vidua, but I don't feel safe calling it that yet. One clue was that it crawled along the bottom like a burrower, which I think is something Cypridopsis vidua does. I know that one species, Potamocypris pallida, looks a lot like Cypridopsis vidua, but it seems to lack the two yellow spots on either side of the eye (the small rectangular black spot near the front).
Contributed by Phil Nosler on 24 December, 2014 - 8:51pm Last updated 29 March, 2015 - 12:58pm |