Overview

• A study published in *Science Advances* confirms clownfish physically shrink in response to marine heatwaves, marking the first recorded case in coral reef fish.
• Researchers found that shrinking increased individual survival odds by as much as 78% during a five-month heatwave in Kimbe Bay, Papua New Guinea.
• Breeding pairs that shrank in coordination showed higher survival rates, highlighting a social dimension to this adaptive strategy.
• The biological mechanism behind this shrinkage remains uncertain but may involve bone reabsorption, similar to marine iguanas under stress.
• Scientists suggest this phenomenon could provide insights into global trends of declining fish sizes, warranting further investigation across species.