Mag. 400x

• A water sample taken on 03/31/2024, from a small vernal stream in a wooded, rocky area (rocks = New England stone wall-sized), using a small sample bottled attached to an extension pole. Air temp 46F.

The size range recorded for the current specimens was 70-130µ (see 2nd image, a composite of 9 specimens). The largest one is shown in the first photograph. All have lightly granulated cell walls and tapered, blunt apices (like inward turned Dixie cup-shapes). G. brebissonii has been previously observed in this slow-moving, rocky, vernal stream; in 2021: https://www.inaturalist.org/observations/72575550). Both geraldojpr and roman_romanov participated in determining the ID and describing its growth characteristics. geraldojpr further refined the ID to Gonatozygon brebissonii var. vulgaris.
What amazes me is that this area is bone-dry during the summer months. Yet algal taxa can be counted on to reappear every Spring... hiding in pockets of moisture? by producing long-lived, durable zygospores? All without roots or an anchor of some kind. Too cool!

Mag. 200x

• A water sample taken on 03/31/2024, from a small vernal stream in a wooded area, using a small sample bottled attached to an extension pole. Air temp 46F.

Two daughter cells, still attached, of a Closterium sp,. More robustly proportioned than C. kuetzingii (fatter, but with similarly tapering and gently curved apices), a diagnosis of Closterium rostratum seems clear, as seen here http://www.digicodes.info/Closterium_rostratum.html. In the 2nd image, "N" marks the nuclear region (which will eventually become centrally located as each daughter cell matures). Also marked are the 2 chloroplasts normally found in Closterium (one per semi-cell on each side of the nuclear region). I could not find an image of a dividing C. rostratum, but a dividing C. venus, as seen here, https://www.photomacrography.net/forum/viewtopic.php?t=25375, serves as a model.

Magnification of photos: 400×, 400×, 400×
Habitat: filamentous green algae (mostly Mougeotia and Spirogyra) and some organic debris collected from a freshwater pond.
Photo taken with a Celestron PentaView Digital Microscope. According to their website, the FOV (i.e. the diagonal width) at 400× is 150 µm.

Magnification of photos: 200×, 200×, 400×, 400×, 600×, 600×
Habitat: filamentous green algae (mostly Mougeotia and Spirogyra) and some organic debris collected from a freshwater pond.
Photo taken with a Celestron PentaView Digital Microscope. According to their website, the FOV (i.e. the diagonal width) at 400× is 150 µm.