Clownfish – also known from the animated "Finding Nemo" – have a remarkable way of meeting stressful situations. American researchers have measured the length of 134 clownfish regularly over five months. They also checked the water temperature at close intervals in the Indo-Pacific region.
The researchers found that in connection with a heat wave, when the water became warmer than usual, the fish shrank – even in length. The fish shrinking increased their chances of survival by up to 78 percent to those that did not shrink.
Moreover, there was a social aspect to the shrinking. The fish that shrank together with their "partner" so that the size proportions between them were maintained, increased their chances of survival even more.
According to the study, published in the journal Science Advances, it is the first time it has been shown that fish shrink in this way in response to environmental changes.
The fish shrank on average by about 2.5 percent and they still do not know how it happens, but it is known since before that other animals can do the same. Certain iguanas can shrink under stress by reabsorbing their bones. The purpose is likely to reduce energy needs.
