Agriculture & Climate Change, UK (Commonwealth Union) – Damselfish, are a family of small, brightly colored marine fish that are generally seen in tropical and subtropical waters worldwide. Damselfish were considered an important part of the marine ecosystem; however recent findings may dispute this idea.
Damselfish have been noted to cause to disruption to ‘cleaning services’ that are essential for healthy reefs, together with climate change, indications are that this is only likely to further deteriorate according to researchers.
The preferred meal for the Caribbean cleaner fish, the sharknose goby are parasites, dead tissue, scales and mucus taken from the bodies of other fishes. When taking away these morsels, gobies offer their ‘cleaning services’ to other marine life, which is a clear example of a symbiotic relationship.
A new study carried out by the University of Cambridge and Cardiff University demonstrates that when gobies inadvertently establish themselves in the territories of aggressive damselfish, they drive away the gobies’ ‘choosy client customers’.
The findings were recently published in Behavioral Ecology, provides an example of a highly unexplored phenomenon: a mutually beneficial relationship in nature obstructed by a third party.
Sharknose gobies work by themselves or in a group setting up a ‘cleaning station’: a fixed area in a specific nook of coral reef, where other marine life burdened by parasites go to benefit from the gobies’ dietary requirements.
“Gobies wait at cleaning stations for customers to visit, similar to shops. And with customers, come the parasites,” explained Dr Katie Dunkley, who is a behavioral ecologist at the University of Cambridge, Department of Zoology. “In return for providing a cleaning service the gobies receive a payment of food.”
The customers Dr Dunkley refers to are a diverse group that include parrotfish, surgeonfish and butterflyfish. The selective client fish shop around, moving to various cleaning stations that are open. When interested, a stationary pose is adopted increasing the chances of a clean, as indicated by researchers.
When a clean occurs that may go from a few seconds to many minutes, the gobies connect with the customer, taking away parasites along with other dead body tissue. A process known known as ‘tactile stimulation’ in addition to eliminating parasites, it can also play a role as a massager lowering the customer’s stress, according to Dr Dunkley. Prior studies have established the significance of cleaners, where their elimination led to lower numbers and less variety of fish species for reefs.
“Cleaning stations act as a marketplace, and if customers stop showing up, over time a cleaning station is going to go out of business,” added Dr Dunkley.
The 5 researchers spent more than 34 hours viewing cleaning stations on a shallow fringing reef in Tobago in a duration of 6 weeks. Using snorkels and waterproof paper they took records of underwater engagements for 10-minute periods from 8am-5:15pm every day.
They discovered that client fish had a lower chance of moving to cleaning stations that were regularly patrolled by damselfish, scaring off ‘intruders’ away.
The territory of Damselfish’s makes up to 70 percent of certain reefs. If the coral reef is healthy, a balance is kept between algae and coral. However, as the reefs get worse and overfishing is elevated, algae flourish. When reefs get disrupted damselfish can end up being more frequent and aggressive. This can result in lesser species getting the goby cleaning treatment required to stay healthy, as indicated by Dr. Dunkley. This may end up leading to the destruction of delicate ecosystems supported by reefs.
“In future we’d like to tease out the motives of damselfish. Are they driven by wanting to protect their algae farms or monopolise cleaning stations?” added Dr. Dunkley, who is also a Charles Darwin and Galapagos Islands Fund Junior Research Fellow at Christ’s College, Cambridge.
