A New Study May Explain Animals' “Sixth Sense”

Schematic of Earth’s magnetic fields (Needpix)

How do sea turtles remember and return to their birthplace? Since 1972, researchers have known that animals such as sea turtles, birds, fish, and lobsters can sense the magnetic field, but the exact mechanism that they use to harness this sixth sense has remained elusive. So, where does certain animals’ sixth sense come from?

Robert Fitak, an assistant professor at the University of Central Florida, along with researchers from Tel-Hai Academic College in Israel and Oxford in the United Kingdom, have hypothesized that certain animals’ magnetic sense comes from the presence of magnetotactic bacteria. Fitak co-authored a paper that asserts this sixth sense may be the result of a symbiotic relationship between the animals and the bacteria.

Salvatore Bellini first documented magnetotactic bacteria was first documented in 1963 when he discovered that some bacteria swim toward the North Pole. This group of bacteria responds to and swims along earth’s magnetic field, which protects earth by deflecting charged particles from the sun. 

The researchers argue that animals’ magnetic sense may come from hosting the magnetotactic bacteria. Fitak made a breakthrough in their study by consulting the Metagenomic Rapid Annotations using Subsystems Technology database, which is one of the largest genetic databases for microbes, to search specifically for the presence of magnetotactic bacteria. While previous studies focused on bigger patterns of the presence or absence of bacteria in animals, Fitak’s study was the first to focus on this specific species of bacteria.

Fitak’s research yielded promising results! He found that some penguins, logger-head sea turtles, bats, and Atlantic right whales have magnetotactic bacteria. The researchers are still unsure where in the body of the animal the bacteria is located, but they believe it could be connected to nervous tissue in the eye or brain. 

As their research continues, the group of researchers will look into developing ways to identify magnetotactic bacteria in other animals. 

“We are now in the middle of experimenting with several species of birds, testing whether antibiotics will affect their magnetic sense,” said Dr. Yoni Vortman of Tel-Hai Academic College. 

The discovery of the symbiotic relationship between the magnetotactic bacteria and certain animals could shape research into how humans interact with Earth’s magnetic field.