Clown fish are now joining the list of animals altering their bodies and behavior in response to climate change. According to a new study published in Science Advances, scientists in Papua New Guinea observed that clown fish, made most famous by the 2003 animated film Finding Nemo, temporarily shrank during a marine heat wave. The team, led by Newcastle University's Melissa Versteeg, documented 134 clown fish over five months and found that some of the fish—normally about 3 inches long—lost 1% to 2% of their body length as water temperatures rose, per NPR.
The shrinking wasn't dramatic, measured in millimeters, but it was enough to boost survival rates. The study reports that clown fish who shrank during heat stress were up to 78% more likely to survive than those that didn't. Scientists suggest the reduced size could mean the fish needed less food and could run their metabolisms more efficiently—key advantages when conditions are tough. Once the water cooled, the clown fish regained their original size. It's not clear what exact processes make the fish smaller, though one theory is that "the fish might be reabsorbing some of their bone material or tissue," per Vox.
However it happens, Versteeg says that ability to shrink, and then bounce back, was unexpected, challenging the usual assumption that bigger is always better when it comes to animal growth. Interestingly, clown fish that lived in breeding pairs shrank together. "It's a beautiful example of really cooperating ... to try and make sure that you come out unscathed [at] the other end," Versteeg tells NPR. If clown fish can shrink to survive, scientists think that similar adaptability might be seen in other coral reef fish facing rising ocean temperatures. (This content was created with the help of AI. Read our AI policy.)
,
uBlock 
,
and
Ghostery 
)
