Peryphyton from an overgrown
lowland reservoir; pH = 6,0; Сm(NO₃⁻) ~ 110 ppm.
Keyed using Ecology and Classification of North American Freshwater Invertebrates, 2nd Ed. Hair chaetae beginning in IV and ventral chaetae with the characteristic double bend. Keys to S. lacustris.
The water sample taken (1 liter) had many of these oligochaetes in it.
A water sample was taken from the shore of lake Istok. The air temperature was 24°C (75.2 °F). The sample was stored at room temperature and observed 2 days after collection.
Video: https://youtu.be/Mq1ohPvAlOE
A water sample was taken from the shore of the Srednerogatsky Pond. The sample had been in room temperature storage until re-assayed.