Mutualistic associations between benthic marine invertebrates and reef taxa are common. Sponge-dwelling gobies benefit from protection within sponge tubes and greater food availability. Sponge-dwelling gobies are hypothesized to increase sponge pumping rates by consuming polychaete parasites, but such increases have not been demonstrated yet. We investigated the association between sponge-dwelling gobies (Elacatinus horsti) and two species of tube sponge (Aplysina lacunosa and Aplysina archeri) in Bonaire, Caribbean Netherlands. We visually assessed goby presence in sponges and used an in situ method with fluorescein dye to estimate pumping rates. Aplysina archeri was more likely to host a goby than A. lacunosa. For both sponge species, pumping rates of tubes with gobies were higher on average than those of tubes without gobies. Our observations, therefore, suggest that E. horsti associations with Aplysina are consistent with a mutualistic relationship in which sponges benefit from higher feeding rates when gobies are present.
Full article can be accessed here: https://link.springer.com/article/10.1007/s00338-023-02362-y