Fish Collection Methods
A variety of methods and net types were used to collect fish while on snorkel or SCUBA. All fish were caught between sunrise and approximately 11:00 h. This time block was selected to maximize the interface between when diurnal fishes begin to feed and when gnathiids may still be active. Details on sampling for each site can be found in supplementary material (Table S1). We did not account for any effect of site because all sites are similar in composition regarding biodiversity and benthic composition, and all have been confirmed to have substantial gnathiid populations (Artim et al. 2020).