Introduction to the Genus Mallomonas

Abstract

The genus Mallomonas Perty 1851 includes unicellular organisms with one bilobed or two chlor-oplasts, an organized covering of siliceous components and two parallel and apically inserted flagella. The siliceous cell covering consists of individual plates known as scales that are imbricated and arranged in a very precise manner (Takahashi, 1978; Wee, 982; Asmund and Kristiansen, 1986; Siver and Glew, 1990). A second siliceous component, referred to as a bristle, also forms part of the cell covering. Bristles are elongated structures that are tucked under the distal portion of a scale and radiate outwards from the cell. Because bristles can rotate, their position may change relative to the longitudinal axis of the cell; they are streamlined when the cell is actively swimming and positioned closer to 90° at rest. The scales are arranged in spiral rows around the cell and aligned in a precise fashion (see Chapter II).