Abstract
Aim: Several drivers explain the reef fish distribution. However, these failed to find evidences if these drivers also explain the distribution and traits of cleaner reef fishes. Here we examine the variation trait of cleaners and test whether historical, environmental, ecological and geographical factors are correlated with cleaner species richness and abundance at the global scale. Location: Tropical and subtropical reefs. Taxon: Actinopterygii. Methods: We tested whether species traits and trait space vary between facultative (i.e., species that clean only during juvenile stages or sporadically) and dedicated (i.e., species that clean during their whole lives) cleaners. We compiled data from local checklists (richness) and belt transects (richness and abundance). We built four models to test whether past and current isolation (i.e., distance from Quaternary refugia and biodiversity centers), sea temperature, primary productivity, local species pool and abundance of potential clients influenced the relative richness and abundance of cleaners. Results: Facultative cleaners had high trait variability which contributed disproportionally to the trait space, whereas dedicated cleaners exhibited low trait variability. Cleaner species richness was higher in the Indo-Pacific and Caribbean, but relative richness and standardized abundance of cleaners were higher in the Atlantic (i.e., North Eastern and Southwestern) and Eastern Pacific. Isolation influenced the relative richness of facultative cleaners, whereas distance to Quaternary refugia, sea temperature, and isolation influenced the relative richness of dedicated cleaners. Local species richness and standardized abundance of cleaner fish exhibited a strong relationship with regional diversity. The standardized abundance of both facultative and dedicated cleaners was influenced by abundance of potential clients and the local species pool, however the effects of each factor varied with the type of cleaner fish. Main conclusions: The small trait space occupied by cleaner fishes may reflect their restricted origin among lineages of reef fishes. Differences in the relative richness and standardized abundance of cleaner fishes across realms suggest a strong influence of biogeographic history. Our results also suggest that cleaner fishes originated mostly on peripheral areas in high latitudes due to the absence of dedicated cleaners. Our results imply that cleaner fishes do not follow the abundance center pattern described for reef fishes due to opportunistic cleaning behavior that originated with higher frequency at locations with low species richness.