Baby reef fish swimming.
Original Published Date: 
Tuesday, June 22, 2021

Full article issued by the ARC Centre of Excellence for Coral Reef Studies (Coral CoE).

A new study led by Adam Downie, a PhD candidate at James Cook University's Coral CoE, has found that baby coral reef fishes can outpace all other baby fishes in the ocean.

Mr Downie says that when considering aquatic athletes, young coral reef fishes shine: they are some of the fastest babies, swimming around 15–40 body lengths per second.

As a comparison, herring babies swim up to two body lengths per second, and the fastest human in the water, Olympic gold medalist Michael Phelps, can only swim 1.4 body lengths per second.

'We found the swimming performance in baby fishes relates to whether they ultimately associate with a reef or not,' Mr Downie says.

'We think that, over evolutionary time, habitat association shaped the swimming performance in the early life stages of these marine fishes,' said co-researcher Dr Peter Cowman, a Discovery Early Career Researcher Award (DECRA) recipient, also from Coral CoE at JCU and Senior Curator of Biosystematics from Queensland Museum’s Project DIG.

The study compared more than 200 marine fish species across their 150 million years of shared ancestry, and found that baby fishes that settle onto a reef later in life, whether tropical or temperate, have evolved to grow larger muscles and swim faster than their non-reef relatives.

Photo credit: 

More than 200 fish species were studied. Reef fish include clownfish, seen here. As babies, reef fish need to find a new reef home—this is when they become some of the fastest baby fish in the ocean. Photo: Katie Sambrook / ARC Centre of Excellence for Coral Reef Studies.