Table 4.

Model results for the MLR analysis (as explained in table 3) of experiments described in §§2.2 and 2.3 conducted with populations of V. carteri, C. reinhardtii and G. pectorale grown at a light intensity of 600 fc. The notation is as in table 3. For V. carteri, the continuous variable T ranges from 1 to 4 to account for the four intervals of 30 min where data were recorded. A § marks statistically non-significant terms. As in the previous analysis, an increase in N_S increases R and C. Moreover, we found that colonies with more cells had smaller r_S, larger U and larger F. In the 2 h measurement window, the colony spheroid, germ cells and flagella continued growing and the cell concentration continued decreasing significantly with time. Interestingly, the flagellar length l was significantly smaller when the cell concentration was large, regardless of treatment. The flagellar beating frequency f was found to be lower when the flagellar length was larger.

	d0	δ	NS (10−3)	T	C	l	r2	F-ratio
C. reinhardtii
rC (µm)	5.90 ± 0.11	−1.25 ± 0.16	—	—	—	—	0.42	19
Vsed (µm s−1)	7.18 ± 0.35	−2.75 ± 0.27	—	—	—	—	0.32	56
Vup (µm s−1)	42.8 ± 2.45	11.41 ± 3.32	—	—	—	—	0.05	12
G. pectorale
rC (µm)	6.61 ± 0.18	−0.31 ± 0.14	−220 ± 30	—	—	—	0.31	11
Vsed (µm s−1)	11.0 ± 0.39	−1.11 ± 0.54	§	—	—	—	0.02	4
Vup (µm s−1)	32.5 ± 1.35	4.21 ± 1.76	§	—	—	—	0.02	6
V. carteri
R (µm)	112 ± 7.6	27.2 ± 3.32	16 ± 4	5.29 ± 1.49	—	—	0.75	37
rG (µm)	26.0 ± 0.70	§	§	0.40 ± 0.26	—	—	0.35	10
rS (µm)	5.13 ± 0.14	−0.25 ± 0.07	−0.27 ± 0.09	§	—	—	0.41	10
l (µm)	19.18 ± 0.59	0.93 ± 0.25	§	0.44 ± 0.10	−0.32 ± 0.05	—	0.67	25
C (cells per 103 µm2)	4.23 ± 0.77	−2.57 ± 0.34	4 ± 0.4	−0.48 ± 0.15	—	—	0.70	29
f (Hz)	39.3 ± 2.45	0.66 ± 0.45	§	§	—	−0.70 ± 0.14	0.26	13
U (µm s−1)	368 ± 21	§	68 ± 11	−10.1 ± 4.23	—	—	0.58	20
F (pN)	1249 ± 105	211 ± 51	443 ± 64	§	—	—	0.68	31
Vup (µm s−1)	274 ± 10.2	26 ± 14.4	§	§	—	—	0.46	16