Favoritos de roman_romanov

Mag. 100x (1), 400x (2,3)
Uroglena (volvox?) colony. Wonderful bagel-shape (sesame seed, of course). What amazing coordination keeps the little flagellates swimming in formation! For a video (a looped 5s segment), see https://youtu.be/IQ4TveQcFVk.

• A water sample was taken on 4/26/2023, from the shore of a Pine Swamp impoundment, using a 10µ dip net to enrich for microbes. Air temp. 58°F.

Mag. 400x
original thinking: Light colored lorica. No flagellum visible. Internal structures visible, like the repetitive ball and stick structures at the posterior margin of the cytoplasm. For information and images see http://cfb.unh.edu/phycokey/Choices/Euglenophyceae/ps_euglenoids/TRACHELOMONAS/Trachelomonas_key.html.
Pursuit of an ID changed direction guided by the evaluation made by @someplant; rather than a flagellate with a lorica, this is a small amoeboid with a test made of plates, capped by a small pseudostome. Someplant astutely called out the sausage-shaped, bright green organelles composed of blue-green cyanobacterial symbiont; making them visually distinct from chloroplasts. See Comments below.

• A water sample was taken on 5/8/2023, from the shore of Lantern Hill Pond, using a 10µ dip net to enrich for microbes. Air temp. 73°F.