Figure 1. Interspecific co-occurrence (a) and intraspecific density (b) of five focal symbiont species from 133 surveyed corals.

Pairwise co-occurrence of five focal symbiont species are shown within Trapezidae (i.e. Crabs – blue), within Alpheidae (i.e. Shrimps – pink), between the two families (Crabs and Shrimps – green). Black circles and solid line represent the observed data. Colored rectangles and dashed lines represent the 95% quantiles from 10,000 randomly simulated communities. Observed values are significantly different from the randomly simulated communities when the black circle falls outside the 95% quantiless. Species tend to avoid to avoid confamilials (with 2 of 4 comparisons demonstrating avoidance), while the crab, T. serenei is positively associated with both shrimp species. At the intraspecific level, pairs are more common and singlets and triplets are more rare than expected by chance. See Appendices B and E for raw data.