Images made through a microscope. All subject types.
first I thought they were small water boatmen. I think it could be daphnia magna, but it is bigger than those I had from pet store.
Last edited by Litonotus on Sat Aug 16, 2014 10:22 pm, edited 1 time in total.
Definitely Daphnia magna, as shown by the sinuous dorsal margin of the postabdomen and the narrow distal portion seen on the first photo. The dorsal spine is on the long side for D. magna, which may at first point to D. similis, but the form of the postabdomen is a clincher. D. magna apparently grows to 6 mm, but I haven't seen them bigger than 4 mm.