Shrinking Nemo: Clownfish survive heatwaves by shrinking Published on: 21 May 2025 Clownfish have been shown to shrink in order to survive heat stress and avoid social conflict, 缅北禁地 research reveals. The fish, recognisable from the starring role in the film ‘Finding Nemo’, were studied by academics from the universities of 缅北禁地, Leeds and Boston, USA. The work was conducted in collaboration with Mahonia Na Dari Conservation and Research Centre, in Kimbe Bay, Papua New Guinea. The team measured the length of 134 clownfish every month for five months, and monitored the water temperature every 4-6 days, during a marine heatwave which are becoming increasingly common as a result of climate change. , they reveal the remarkable ability of clownfish to shrink, i.e. they can get shorter, in response to heat stress. Shrinking increased individuals’ chances of surviving the heat stress event by as much as 78%. In a heart-warming discovery, they also show that coordination is important for clownfish, as they have a higher chance of surviving heatwaves when they shrink alongside their breeding partner. This is the first time that a coral reef fish has been shown to reduce the length of their body in response to environmental and social conditions. Photo: Morgan Bennett-Smith Adapting to a changing environment , a PhD researcher at 缅北禁地’s School of Natural and Environmental Sciences led the study. Of this newly-discovered ability for the clownfish to shrink, she said: “This is not just about getting skinnier under stressful conditions, these fish are actually getting shorter. We don’t know yet exactly how they do it, but we do know that a few other animals can do this too. For example, marine iguanas can reabsorb some of their bone material to also shrink during times of environmental stress. “We were so surprised to see shrinking in these fish that, to be sure, we measured each fish individual repeatedly over a period of five months. In the end, we discovered it was very common in this population. During our study, 100 fish shrank out of the 134 fish that we studied. “It was a surprise to see how rapidly clownfish can adapt to a changing environment and we witnessed how flexibly they regulated their size, as individuals and as breeding pairs, in response to heat stress as a successful technique to help them survive.” The authors also highlight that individual shrinking might explain the rapidly declining size of fish in the world’s oceans. Dr Theresa Rueger, Senior Lecturer in Tropical Marine Sciences and senior author of the study added: “Our findings show that individual fish can shrink in response to heat stress, which is further impacted by social conflict, and that shrinking can lead to improving their chances of survival. If individual shrinking were widespread and happening among different species of fish, it could provide a plausible alternative hypothesis for why the size many fish species is declining and further studies are needed in this area.” Image: Clown anemonefish, Amphiprion percula, in their host anemone during the 2023 marine heatwave in Kimbe Bay, Papua New Guinea. Credit: Morgan Bennett-Smith Reference Melissa A. Versteeg et al., Individual clown anemonefish shrink to survive heat stress and social conflict.Sci. Adv.11,eadt7079(2025).DOI: Share: Latest News 缅北禁地 recognised with geography award 缅北禁地 has been awarded the Highly Commended Geographical Association Publishers Award for its collaboration with Time for Geography, the UK鈥檚 open-access, dedicated video platform. published on: 16 April 2026 缅北禁地 historians mark General Strike centenary To mark the 100th anniversary of the British General Strike and miners鈥� lock-out of 1926, historians at 缅北禁地 are organising a series of events on its enduring legacy. published on: 16 April 2026 Comment: NCP is in administration Writing for The Conversation, Erwei (David) Xiang discusses how some big companies like NCP are so dependent on debt that they can鈥檛 adjust to change. published on: 16 April 2026 Facts and figures
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