Clownfish shrink their bodies to survive ocean heat waves

To survive warming oceans, clownfish cope by shrinking in size.

To survive warming oceans, clownfish cope by shrinking in size.

Scientists observed that some of the orange-striped fish shrank their bodies during a heat wave off the coast of Papua New Guinea. Fish that slimmed were more likely to survive.

Heat waves are becoming more common and intense underwater due to climate change. Warmer water temperatures can bleach sea anemones that clownfish call home, forcing them to adapt to stay alive.

Scientists monitored and measured 134 colorful clownfish in Kimbe Bay during an intense heat wave in 2023 that’s still bleaching corals worldwide. They found that 101 clownfish decreased in length on one or more occasions from heat stress.

“We were really shocked at first when we saw that they were shrinking at all,” said study author Morgan Bennett-Smith with Boston University. The findings were published Wednesday in the journal Science Advances.