Characiellopsis

Characiellopsis is a genus of green algae in the family Characiaceae. Two species are known: Characiellopsis anophelesii and Characiellopsis skujae.

Description
Characiellopsis consists of solitary cells that are elongate and attached to a substrate via a pad of mucilage. Cells contain a single central nucleus. Young cells contain a single chloroplast, while older cells contain multiple; each chloroplast has a single pyrenoid. Cells reproduce by 2-flagellated zoospores. These zoospore escape from the tip of the mother cell via a tear in the mother cell's wall.

Species
Characiellopsis anophelesii consists of solitary cells that are attached to mosquito (Anopheles) larvae.

Characiellopsis skujae consists of solitary cells that are elongated to ovoid, attached to a surface via a thick stalk. The cell walls are very thick, and the tip of the cell has a refractive ring-shaped structure visible in light microscopy. Cells contain a single chloroplast filling the cell, each with a single pyrenoid. The apical ring structure is very distinctive, and it shares this characteristic with another taxon, Characium obtusum; the two species are probably synonymous.