FIGURE 2.

Social feeding behavior during long-term culturing on the dense algal (Tetraselmis marina box) and rice (for H1-f) substrates (illustrated examples). The aggregation of animals depended upon the density of the substrates (see mode #3 in the text and Figure 3). This behavioral pattern was observed for all haplotypes (H1, H2, H13—in Petri dishes). The arrow in c indicates a fission process. Aggregates often included 2–15 individuals. For example, there were aggregates of 2-3 animals in H2 (A–C) on Tetraselmis marina, and 9 H1 individuals (E) at the same substrate; but H2 often forms aggregates for 10–15 animals around rice grains (G–I). pH = 8.2. Scale bar: (A–D)—100 μm, (E)—1 mm, (F–I)—500 µm.