Tunabot Can Give Real Tuna Fish a Run for Their Money

It might be surprising to some readers who have only ever seen tuna fish in a tin at the grocery store, but tuna fish can grow to be very large. The Atlantic Bluefin tuna, which is the largest species of tuna and also one of the most overfished, can grow up to 15 feet in length and weigh up to 1,500 pounds. Despite their large size, tuna fish are capable of swimming efficiently over large distances or in very quick bursts to catch prey or to evade their own predators. A team of researchers from the University of Virginia have recently developed Tunabot, a robot that can give real tuna fish a run for their money.

Tunabot was built by these researchers, including the Henry Bryant Bigelow Professor of Ichthyology George Lauder, to better understand how tuna and other fish are capable of swimming both quickly and efficiently.

can reach speeds of up to 40 mph, but are still able to swim across large swaths of the Atlantic Ocean before returning to one of two known spawning grounds—one in the Gulf of Mexico and the other around the Balearic Islands in the Mediterranean Sea. While tuna aren’t the only fish capable of such feats, their abilities make them worthy of study.

It’s difficult to study living tuna fish behavior and capability in the open ocean, and they act differently in captivity. That’s why the researchers built Tunabot. The tricky part was getting its movement accurate enough to replicate the speed and efficiency of tuna fish. As it turns out, they were able to do that in a fairly simply manner with help from a team at UVA’s Mechanical and Aerospace Engineering department. The solution they came up with was to attach a bent shaft to an electric motor. As the shaft spins, it pushes out against Tunabot’s flexible body. That causes the tail to flap back and forth and propel the robot forward.

In testing, Tunabot was capable of flapping its tail up to 15 times per second. It could also swim a distance as far as 5.5 miles on a single charge from a battery approximately the size of what you’d find in a smartphone. They were able to compare Tunabot to real 6-foot-long Yellowfin tuna that are being raised in Rhode Island. While Tunabot isn’t nearly as large, it does seem to display many of the same characteristics as its living counterparts.