FIG 3.

Weak pairwise interactions in five-species experiments. (A) Abundance per zebrafish gut of one of the bacterial species, Enterobacter sp. strain ZOR0014, when all five species are coinoculated (gray) and in each four species coinoculation experiments (green), with the omitted species indicated on the axis. Each circular data point is a CFU value from an individual fish (N = 40, 12, 12, 11, and 9, from left to right), with the mean and standard deviation indicated by the square marker and error bars. (B) Matrix of pairwise interaction coefficients, $C_{\mathit{ij}}^V$, when 5 bacterial species are present. The coefficients outlined in black differ from zero by over three standard deviations (see Fig. S2B). (C) The pairwise interaction coefficients inferred from 4- to 5-species experiments versus those from 1- to 2-species experiments. The colors label species i for each interaction pair. (D) The minimum interaction coefficient calculated from a power law interaction model for different values of the exponent α for the 1- to 2-species (square filled markers) and the 4- to 5-species (square markers) experiments. AC, Acinetobacter calcoaceticus; AE, Aeromonas sp. strain ZOR0001; EN, Enterobacter sp. strain ZOR0014; PL, Plesiomonas sp. strain ZOR0011; PS, Pseudomonas mendocina.