Metacystis sp.

Metacystis is a genus of prostomatid ciliates, many species of which live in pretty vase-like loricas. This one has a fairly narrow, annulated lorica. I found one last year, on my first visit to the Mer Bleue sphagnum bog. It looks a bit like Metacystis annulata, originally described by Stokes as Vasicola annulata (“An undescribed Vasicola with an interesting habit,” 1895), and moved by Kahl to the genus Metacystis. The lorica in Stokes’s drawing stands on a short stalk, but the Metacystis I’ve found in Mer Bleue lacks this feature. Stokes’s species was found in brackish water, and similar Metacystis species (M. truncata, M. hyperhalina) are described as marine.

A similar observation from iNaturalist: https://www.inaturalist.org/observations/147671668

Body length 76 μm Collected in Mer Bleue conservation area, in mid May, 2013. Olympus BHB 100X oil immersion obj. (1000X)