Scientists have discovered evidence for a new form of collective sensing that appears to allow elephantnose fish to expand their perceptual reach
NEW YORK, March 6, 2024 /PRNewswire/ — It would be a game-changer if all members of a basketball team could see each other’s eyes in addition to their own. A research duo in Columbia’s The Zuckerman Institute found evidence that this type of collective sensing occurs in a close group of African weakly electric fish, also known as elephantnose fish. This instantaneous sharing of sensory intelligence can help fish find food, friends and enemies.
A weakly electric fish like this one, Gnathonemus petersii, may be picking up on sensory information picked up by nearby fish. (Credit: Sawtell lab)
“In engineering, it is common for groups of emitters and receivers to work together to improve sensing, for example in sonar and radar. We have shown that something similar may be happening in groups of fish that sense their environment using electrical pulses . These fish seem to ‘see better in small groups.’ said Nathaniel SawtellPhD, a principal investigator at Columbia’s Zuckerman Institute and a professor of neuroscience at Columbia’s Vagelos College of Physicians and Surgeons.
In a paper published online today at NatureDr. Sawtell and postdoctoral research associate Federico PedrajaPhD, brings together multiple lines of evidence to argue that the electric fish species they study, Gnathonemus petersiiperform lightning-fast feats of collective sensing never before documented in biology.
Scientists have long known that electric fish sense changes in the electric fields they project into their waterscapes, similar to the acoustic signals emitted by bats and dolphins. Fish rely on special organs in their skin that emit and sense electric fields to communicate. They also use them for an electrical version of echolocation to detect, track and identify various objects in their watery environment.
G. petersii Electric fish live in dark and dark African river habitats, where the fish’s eyes are of limited value. Thinking about that challenge with an engineering mindset, Dr. Pedraja and Sawtell hypothesized that fish may have had sensory capabilities similar to networked radar and sonar systems, that multiple units could work together to see objects further and in greater detail. than disconnected units.
To test whether this principle of collective sensing applied to electric fish, the researchers first developed a computer model in which they could simulate the fish’s electrical environment. They tested whether individual electric fish were better at detecting objects by tapping into signals emitted by nearby fish.
“Think of these external signals as electrical images of objects that automatically produce nearby electric fish and beam to nearby fish at the speed of light,” said Dr. Pedraja. “Our work suggests that three fish in a group can each receive three different “electrical views” of the same scene at roughly the same time,” added Dr. Sawtell.
Among the best results of the simulation study, said Dr. Sawtell, is that collective sensing can extend the electro-location range of electric fish up to 3 times. The researchers say that such a large sensory enhancement would almost certainly provide safety benefits.
The researchers then looked for an actual neural basis for such an ability to G. petersii. Recordings in a part of the brain dedicated to the electrosensory system showed that fish respond to their own electric discharges and to external electrical signals from, for example, other electric fish or lab-generated mimics of signals. What is particularly exciting to scientists is how closely the patterns of brain activity match those suggested by simulation studies that researchers can see in neural recordings.
Behavioral observations add further evidence that fish do indeed engage in collective perception. In tanks, fish assume in-line and right-angle formations that the computer model shows are favorable for collective sensing. Also, recordings of a type of electrical dialog between fish feature highly precise turn-taking in which the fish emit their electrical discharges in strict alternation. The authors hypothesize that this behavior, previously called the “echo response,” may play an important role in coordinating collective sensing.
As researchers discover a new sensory ability, more fascinating questions arise for them.
“These fish have some of the largest brain-to-body mass ratios of any animal on the planet,” said Dr. Sawtell. “Perhaps this enormous brain is necessary for rapid and highly efficient social sensing and collective behavior?”
The researchers noted that learning more about the brain mechanisms involved could provide leads for artificial sensing technologies for applications including autonomous underwater vehicles and medical imaging.
The paper“Collective Sensing in Electric Fish,” by Federico Pedraja and Nathaniel Sawtell of Columbia’s Zuckerman Mind Brain Behavior Institute, is published online at Nature in March 6, 2024.
The authors report no conflicts of interest.
Contact: Ivan Amato, [email protected]; 301-919-0626
SOURCE Columbia University Zuckerman Institute
