Click on the image which your specimen most closely resembles.
Swimming fins
(sf)
strongly serrated;
posterior end is flat or medially convex
Swimming fins
(sf)
not strongly serrated;
swimming fins very narrow, posterior end is concave
Taxonomy
Phylum
Rotifera
Class
Monogononta
Order
Ploima
Family
Synchaetidae
Genus
Polyarthra