I am going to start a running catalogue of the diverse arthropod microfauna of my reef tank. Here is my first attempt to capture one of these tiny animals. This is a sediment-dwelling ostracod, about 250 microns in carapace length.
I know, ugly photo, but this was a first attempt. Can anyone ID it further? The rubble in the tank was aquacultured on the gulf coast of Florida, but this little guy could have hopped on at the fish store.