Mag. 200x
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.
introduced
brought by strong waves