Aggressive coral reef farmer fish scare away cleaning fish customers

Scientists have noticed that some aggressive pomaceous fish can interfere with the cleaning of other fish species. It is reported by the University of Cambridge.
The favorite diet of the Caribbean cleaner fish, the goby Elacatinus evelynae , consists of parasites, dead tissue, scales, and mucus scraped off the bodies of other fish. By removing these bits, the gobies offer their “cleaning services” to other marine life, a prime example of a mutually beneficial relationship between species. These fish can work alone or, together with other relatives, choose a place on the coral for a “cleaning station”, where other species of fish consciously swim.
A new study published in Behavioral Ecology shows that if such stations are located in the habitat of some pomacentric fish, they interfere with their work with aggressive behavior.
Scientists spent more than 34 hours monitoring cleaning stations on a shallow reef in Tobago for six weeks. They found that client fish were less likely to go to treatment plants, which are more often patrolled by pomacentres to scare off “intruders.”
“These fish act like farmers, weeding out the algae they don’t need in order to encourage the growth of their preferred algae species. Pomotherines defend their algal territories and spend a lot of time on patrol, scaring off intruders by biting, attacking, and chasing them,” the authors explain.
Territories of pomacentres cover up to 70% of some reefs. A healthy coral reef maintains a balance between algae and corals. But as the condition of the reefs deteriorates and overfishing intensifies, the algae are thriving. In turn, this can lead to the spread of pomacentric fish, which will seriously interfere with the cleansing of the body of the fish, which is important for their health. Ultimately, this could lead to the destruction of fragile coral reef ecosystems.
In the future, the authors would like to find out the motives of the pomacentres – whether they are simply trying to protect their “farms”, or if they hope to monopolize the treatment plants, which they do not use very often.