The Steephead parrotfish (Chlorurus microrhinos), seen here at Lizard Island, Australia, is a large vegetarian fish. Image credit: Victor Huertas.
Original Published Date: 
Thursday, July 16, 2020

Full article issued by the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU).

An ARC-supported study has revealed that the diets of reef fish dictate how fast different species evolve. The breakthrough adds another piece to the fascinating evolutionary puzzle of coral reefs and the fishes that live on them.

“Up until now we knew that many factors could have influenced the pace of reef fish evolution, but these factors were never examined altogether,” says Alexandre Siqueira, the study’s lead author from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU).

Co-author and ARC Discovery Early Career Researcher Award (DECRA) recipient, Dr Peter Cowman, also from Coral CoE at JCU, says that by building an evolutionary ‘tree of life’ for nearly all fishes associated with reefs, they were able to examine the variation in rates of species formation.

The ‘tree of life’ contains more than 6,000 fish species that live on coral reefs across the globe. Ecological and geographical data—such as diet and geographical range—were also gathered for the majority of these species. A surprising result was the discovery that what really matters in reef fish evolution isn’t geography, but what fish eat and how big they get.

The study offers a new way of looking at reefs with a functional, rather than taxonomic, approach. Very little is known about the functional evolution of reefs: what they do and how they work. Scientists previously only looked at how many reefs there were and what species were present.

“In this study it was important to understand the origins of the functional role a fish species plays on a reef—not just the species itself,” Dr Cowman said.

Photo credit: 

Image: The Steephead parrotfish (Chlorurus microrhinos), seen here at Lizard Island, Australia, is a large vegetarian fish. Credit: Victor Huertas.