Clownfish Shrink to Survive Heatwaves, Study Finds

A new study led by Newcastle University has found that clownfish in Papua New Guinea, notably made famous by 'Finding Nemo,' can shrink their bodies to survive marine heatwaves, such as the 2023 event. Researchers observed that up to 75% of the monitored clownfish temporarily shortened during the heatwave, which improved survival odds by up to 78%. This shrinking is often coordinated among breeding pairs and may involve bone reabsorption, similar to adaptations seen in marine iguanas. While this response enhances short-term survival, scientists warn it could reduce reproductive output, potentially threatening long-term population stability. This is the first documented case of a coral reef fish shrinking in response to environmental and social stress. The study highlights both the resilience and vulnerability of marine life as ocean temperatures rise.