A recent study highlights the importance of the many tiny bottom-dwelling fish that make up the coral reef ecosystem.
The next time you come across the tiny fish going about their business at a coral reef, take a moment to contemplate their important role in the reef ecosystem.
Not just by enhancing the beauty and vibrancy of the reef, they also ensure the survival of the reef community.
Known as cryptobenthics, these bottom-dwelling fish serve as fuel that powers the entire ecosystem. These fish and their larvae make up nearly 60 percent of the biomass production of the reef.
Comprising species like blennies, gobies and cardinalfish, they spend much of the lives hiding from and evading predators, living in the gaps of the coral structure. Generally, they live a few weeks or months as adults before ending up as fish food for the larger fishes in the community.
“Because of their size and tendency to hide, these little fish are commonly overlooked,” says Simon Brandl from Simon Fraser University in Canada, “but their unique demographics make them a cornerstone of the ecosystem.”
Dr Brandl is the lead author of a recent paper in the Science journal on this topic. In the study, the team had looked at reefs worldwide and the records of larval abundance. They discovered that cryptobenthics and their larvae make up nearly 60 percent of all fish flesh eaten on the reef.
“Their populations are completely renewed seven times a year, with individuals in some species living only a few days before they are eaten. The only way they can sustain this is by a spectacular supply of local larvae,” adds co-author Renato Morais, a PhD student at the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University (JCU).
As co-author Professor Bellwood, also from JCU, summarises: “Their extraordinary larval dynamics, rapid growth, and extreme mortality underpins their newly discovered role as a critical functional group on coral reefs.”