Description of Frontonia vernalis: Peniculine ciliate, eats diatoms, green algae, and other large particles of food, but has symbiotic green algae. Members of the genus have postoral kineties usually to left of oral poykinetids. Left edge is more curved than right edge; cytopharynx with numerous strong fibrils; ectoplasm with numerous fusiform trichocysts; macronucleus oval; one to several micronulei. Widespread but usually in regions with limited or unreliable oxygen supply. Ecology: - B.J.Finlay, U.G.Berninger, L.J.Stewart, R.M.Hindle, and W.Davison; Some factors controlling the distribution of two pond-dwelling ciliates with algal symbionts (Frontonia vernalis and Euplotes daidaleos). J.Protozool. 34(4):349-356, 1987.