The Secret to Tuna's Endless Swimming: Sleeping on the Go

Tuna, also known as "tunny," are remarkable fish that are considered super swimmers because of their ability to swim endlessly without rest. Unlike other fish, tuna cannot freely control their gills, so they need to keep their mouths open to let seawater flow through the gills in order to obtain oxygen. This unique respiratory system enables them to swim at high speeds for extended periods of time.

But how do they manage to keep going without rest? It turns out that tuna have a fascinating adaptation that allows them to sleep while swimming. They let the left and right brain take turns to rest, so they can keep swimming while still getting the rest they need. This remarkable ability allows them to swim non-stop for their entire lives.

In addition to their remarkable swimming abilities, tuna are also unique among fish because of their countercurrent heat exchange system. This system allows them to maintain a higher body temperature than the surrounding seawater, which is critical for their ability to swim at high speeds for extended periods of time. The heat generated by their muscles is kept within their bodies, which enables them to maintain their body temperature even in cold water.

Image Credit: leeyounghee

Tuna are highly prized for their meat, which is a popular ingredient in many dishes around the world. However, overfishing has led to a decline in tuna populations, and many species of tuna are now endangered.