Description of Bacillaria

Cells (called filaments) are elongated and motile, sliding along each other, in stacked colonies. Cells are rectangular in side view. Two large plate-like chloroplasts are present, one near each end of the cell. The nucleus is located centrally. Cells are yellow-brown in color [1].

Figure 2. Examples of Bacillaria colonies and close-up images of single cells using Scanning Electron Microscopy (SEM). Courtesy Figures 27-30 in [3]. Click to enlarge.

The stacked colony moves by pairs of individual cells sliding against each other. This synchronized movement [4] is like an accordian in that the displacement ripples across the extent of the colony and results in large positional changes. This results in cyclic gliding movements resulting from the action of actin filament motors [5]. The primary movement pattern also has a number of interesting properties, including the potential for explosive kinetics resulting from higher-order derivatives of motion.