[2] These euglenoids have also been observed to prefer warm, eutrophic waters, increasing in abundance during harmful algal blooms of Planktothrix agardhii.

[2] Trachelomonads are free-swimming, solitary, photosynthetic flagellates ranging in size from 5-100 um, with an ovoid shape, sharing similar morphological characteristics with its sister group, Strombomonas.

[2][6] These cells are enclosed in a rigid, shell-like envelope, made up of minerals and polysaccharide mucilage, with a defined collar or truncate extension that surrounds an anterior apical pore where the flagellum emerges from, also known as a lorica.

[2][7] The lorica can be distinguished between different species by the orientation of spines or other ornamentations, such as pores, warts or ridges, and can range from being colourless to orange/brown or even black based on the nutrients in their surroundings.

[8][2] Most species are phototrophic, having a characteristic green colour due to the discoid or flattened, shield-like chloroplast, which usually bears sheathed, projecting or naked pyrenoids.

[9] Then manganese and ferric hydroxide compounds are precipitated on the inner fibrillar layer to produce a thick envelope and the original external skin is lost.