Greater siren tank (1)

A 65 gal. tub with ~55 gal. of water in it, housing a greater siren (Siren lacertina) that's part of a mark-recapture population study. Also in the tank: southern naiad (plant), duckweed, freshwater shrimp, mosquitofish, sm. crayfish, 2 brown hoplos (armored catfish).