Phylum: Heterokontophyta   Family: Chlorobotryaceae

Characiopsis minuta (A. Braun) A. Borzì 1895

First described by Braun ex Kützing (1849: 892) as Characium minutum. It was later moved by Borzì (1895: 152) to its current position. One of numerous algae that grow attached to filamentous algae and other substrates. This species tapers to the apex but can present different profiles depending on the angle it was photographed at.
Cell dimensions: L: 12-20 µm; B: 5-7 µm.
Probably widespread but infrequently recorded due to its small size. Found in circum-neutral waters with aquatics.

References: 
Borzí, A. (1895). Studi algologici: saggio di richerche sulla biologia delle alghe. Fasc. II.
Braun, A. [in] Kützing, F.T. (1849). Species algarum.
John, D.M., Whitton, B.A. & Brook, A.J. (2011 second edition). The Freshwater Algal Flora of the British Isles.