New research from the University of Cambridge and Cardiff University shows that when gobies inadvertently set up shop within the territories of aggressive damselfish, the damsels often scare away the gobies’ clients. The study, published in Behavioral Ecology, is an example of a largely unexplored phenomenon: a mutually beneficial relationship in nature being disrupted by a third party.
Caribbean Sharknose gobies Elacatinus evelynae work singly or band together and set up a “cleaning station,” a fixed location in a particular area of a coral reef, where other marine life can go to take advantage of the gobies’ dietary needs. For the sharknose goby, this is a mix of parasites, dead tissue, scales and mucus picked off the bodies of the visiting fishes which can include grazing species, such as surgeonfishes and butterflyfishes amongst others.
“Gobies wait at cleaning stations for customers to visit, similar to shops. And with customers come the parasites,” said Dr. Katie Dunkley, a Behavioural Ecologist at the University of Cambridge’s Department of Zoology. “In return for providing a cleaning service, the gobies receive a payment of food.”
As “farmers” of certain algae species though, Damselfishes are protective over their algal territories, and spend a lot of time patrolling them, scaring away intruders through biting, attacking, chasing or threatening displays. Their territories cover up to 70% of some reefs, but on a healthy coral reef, a balance is maintained between algae and coral. As reefs deteriorate though, algae thrive and damselfish may become more common and/or aggressive. This can lead to fewer species receiving the goby cleaning treatment needed to keep them healthy, and could ultimately contribute to the breakdown of the delicate ecosystem.
Image credit: Kate Dunkley
More information: Katie Dunkley et al, The presence of territorial damselfish predicts choosy client species richness at cleaning stations, Behavioral Ecology (2023). DOI: 10.1093/beheco/arac122
Journal information: Behavioral Ecology