(you-trep-tea-ella), a marine euglenid. The autotrophic euglenids (the ones with chloroplasts) are usually thought of as being freshwater organisms. A small number of species are found in marine habitats - the most commonly reported being Eutreptia
(flagella equal in length) and Eutreptiella
(flagella unequal in length) . Both have two or more emergent flagella, and these beat actively to propel the cell through the water. Euglenids have chlorophyll b in the plastids, and this gives them a bright green colour. The eyespot (stigma) lies outside the plastids. Euglenids are distinguished, in part, by the ridges under the cell membrane. Differential interference contrast.