Which way did the fish fishes find to survive in the heat of the oceans

Cleon fish found a way to survive the oceans, whose waters are heated due to climate change. Shrink their bodies.

Scientists noticed that some of the fish with characteristic white and orange stripes reduced their body volume during a heatwave off Papua Guinea. The « slimming » fish were more likely to survive.

Marine heat waves are increasingly often due to climate change and change the behavior of fish. Sea water overheating has been found to be discolored by marine anemones. These marine animals, which look like flowers, act like a house for fish-clone. The discoloration allows them to survive in the new climate condition.

Reduced their body length

Scientists watched 134 colorful fish-gulf in the Gulf of Kibe during a strong heatwave in 2023. The consequences of this heat are still visible: it still whitens corals around the world. They found that the length of the body was reduced to 101 fish in one or more thermal stress.

« We were really shocked at the beginning when we saw that they were shrinking, » said study author Morgan Benett-Smith of the University of Boston. The findings were published Wednesday in the journal Science Advances.

Scientists do not yet know how the fish-clown shrinks. One hypothesis is that they somehow absorb their bone material again. It is likely that when they are smaller in size, the fish are saving energy during thermal wave and need less food.

Pair in sync

It was also found that some pairs of fish are in a phase of breeding, congratulated their shrinkage to increase their chances of survival.

Cleon fish are not the only species that shrinks in size to withstand the heat. The same phenomenon has been observed in the sea iguana, during the period of El Nihio in the Galapagos islands. But this is the first time the phenomenon has been observed in fish of coral reefs.

According to Ocean Ecologists, Simon Tromold, of the Oceanographic Institute of Woods Hole, the fish acquired « another tool to face the changing world ». But it’s still too early to find out if the fish-cloves will continue to react in the future.

After all, as the researchers found, the shrinkage was temporary. When their environment became less hot, they were again growing in their normal size. For Melissa, of the University of Newcastle, of the authors of the study, « these natural systems are really under pressure, but there is incredible durability. »