Until recently, it was believed that only primates and ravens could use gestures (the equivalent of sign language in the animal kingdom) to help one another hunt. Now, researchers have discovered that at least two types of fish, with very tiny brains, once believed not up to the task, are able to use referential gestures to help identify prey to others.
According to NBC News, both grouper and coral trout, are able to use gestures when hunting for food with their partners. In the case of grouper, they tend to hunt with Moray eels and a fish known as Napoleon wrasse. Coral trout, on the other hand, work hand in hand with octopi. In both cases, the grouper and trout use their bodies to indicate to their fishing partners just where the prey is hiding.
New study confirms this fishy behavior
Researchers writing in the journal of “Nature Communications” described the process in which a paired grouper or coral trout identifies its prey. The fish would then point its head downward and shake back and forth to clue the eel or octopus of the location of the hidden prey. According to NBC News, this gesture is known as a “headstand signal.”
According to Redouan Bshary of the University of Neuchatel in Switzerland and author of the breaking research, chronicled by National Geographic, “There’s this idea that you need a large brain to use referential gestures, [but] even a fish with a rather standard brain shows this ability to produce referential gestures. This is important. It’s decoupling cognitive abilities from brain size.”
Advantages of working together
To many, an astounding discovery may be that the fish learn to work together in the first place. This despite the fact that the process does not lead to any “sharing” of the meal. Whichever fish gets to the prey first consumes it whole. So why share the information with another predator?
While grouper and trout have a quick burst style of hunting, species like the octopus and the eel can pursue prey through small spaces. As for the wrasse fish, they have strong jaws, able to crush coral to reach the prey.
It appears that this sharing system works to the benefit of the grouper and trout. According to National Geographic, even with more than one species competing for the prey, the grouper or trout is more successful in obtaining food. “When hunting alone, groupers only catch their prey about 1 out of every 20 attempts, Bshary said. When they have help, the ratio is significantly better—about 1 out of 7, he added.”
Fish as fascinating creatures
While the sign language used by the fish was observed after hours spent with them in the wild, the next step will be for the scientific researchers to recreate the conditions in the laboratory.
According to National Geographic, humans may have much more to learn about how fish communicate. Another study by British and Canadian scientists revealed that herring “communicate by breaking wind,” which creates high-frequency sounds, although the scientists have yet to interpret what the communication means to other fish.
