Figure 7. The effect of algal food composition on T. adhaerens growth and appearance.

T. adhaerens was cultured similarly as shown in Fig. 6 and all animals were photographed and analyzed using ImageJ program for their number (A), mean area (B), mean perimeter (C), mean perimeter/area ratio (D) and mean isometric quotient (E) after one week. Ch—stands for feeding with Chlorella sp., Rh—Rhodomonas salina, Po—Porphyridium cruentum, and their combinations. 3Rh stands for a culture with three times higher concentration of Rhodomonas salina and 3Ch for three times higher concentration of Chlorella sp. (A) shows that addition of Rhodomonas salina (Ch + Rh) greatly increases the number of animals observed after one week of culture. This effect is even more pronounced in cultures containing all three algae, while three times bigger concentration of only one type of algae (Ch and Rh) has little or no effect. This is even more pronounced when the area and perimeter are determined (B and C). Determination of the isoperimetric quotient in individual cultures indicates that cultures with Rhodomonas salina have a significantly smaller ratio, suggesting higher proliferative rate of structures at the animal circumference (E). Bars represent 95% confidence interval. Raw data are provided as Files S5 and S6.