Sust. FEM. 1 Genus of protists ( Kingdom of organisms equipped with animal characteristics and plant ) flagellates of waters both 'sweet' as brackish, often classified as algae formed by single-celled organisms that produce zoospores equipped with a resonant tab. They tend to abound in stagnant water so that the surface color of green, by the species ' Euglena viridis ', or red, the "e. sanguinea', as well as in water rich in organic matter. They have a red Eyespot, organelle composed of granules of carotenoid pigment. Most of more than 800 species have photosynthetic chloroplasts, which can be: 1 ) autotróficas: by photosynthesis generate complex organic compounds like carbohydrates, fats and proteins, from simple inorganic molecules, or - by chemosynthesis - cause inorganic chemical reactions, such as vegetables; 2 ) heterotrophic: inaptos agencies for the fixation of carbon inorganic ) ( by which rely on organic carbon, as animals. From the Greek "eu": well, bonito, and «Glenn»: eye orbit. (Sources: ) Wikipedia; (b) ) Encyclopedia of language; c ) Great encyclopedia of 41 worldwide;