Trumpetfish like to feed on damselfish and shrimp on coral reefs and sea grass beds around the world. But with 20-inch-long bodies and conspicuously large snouts, they need tricks to sneak up on their prey.
In one study, published on Monday in the journal Current Biology, scientists demonstrated the effectiveness of a trumpetfish strategy – hiding behind a larger, friendlier fish. The trickery of such a fake out seems almost human in its intelligence, leading scientists to wonder if other species also use similar hunting techniques.
While there are many residents of coral reefs, such as grouper and moray eelsworking together when hunting for their mutual benefit, the stealthy shadowing of the trumpetfish by the larger fish seems to be only for its own benefit.
Nor is this the only way trumpetfish catch prey off guard. It can change color to blend in with its surroundings or pretend to be inanimate objects such as sticks or seaweed. It can also attack from above, hanging vertically in the water column and descending to suck prey in its gaping mouth.
However, hiding behind a larger nonpredatory fish, such as the parrotfish, until its prey is within striking range, seems to be one of its favorite hunting strategies.
“For the past few decades, guidebooks, dive blogs and some research papers have documented observations of this behavior,” said Sam Matchette, a behavioral ecologist at the University of Cambridge and an author of the new paper. -student
Historically, humans have used a similar strategy when hunting waterfowl. Hunters hide behind “stalkers,” which are horses or cattle, when approaching ducks to prevent the birds from seeing them and spooking them. Many hunters still use this technique, but instead of farm animals they use blinds and cardboard cutouts.
Heard Dr. Matchette reports that trumpetfish hide behind larger non-predatory fish when hunting, and the tactic is remarkably similar to the horse stalking technique used by humans. So last year, Dr. Matchette and his colleagues set out to see if they could prove that the trumpetfish were indeed doing something similar to the duck hunters of old.
To test their hypothesis, the researchers made 3D-printed models of trumpetfish and parrotfish and attached them to a wire pulley system that they set up near a damselfish colony on a coral reef in Curaçao. The researchers then pulled the fake fish along the wire, simultaneously, and filmed the damselfish’s reaction.
When the trumpetfish model is pulled on the wire, a nearby damselfish swims up to investigate it but then quickly runs away, clearly seeing it as a threat. When presented with the parrotfish model, however, the damselfish swam to investigate it but otherwise did not respond to its presence. Similarly, when the trumpetfish model is attached to the side of a parrotfish model and the damselfish is pulled, the fish does not escape.
“Although fish biologists have known about this for a long time, this is the first time someone has done an experiment that has shown how advantageous this strategy is to trumpetfish,” said Luiz Rocha, the curator of ichthyology at the California Academy of Sciences.
This horse stalking technique is highly effective, says Dr. Rocha, adding that many other non-human animals likely use it. “I’d be really surprised if there wasn’t,” he said.
said Dr. Matchette agreed. “There are probably more examples out there, but we haven’t seen them yet,” he said.
He also suggested that as coral reefs around the world decline due to climate change, the horses’ behavior may become more prevalent. With fewer coral shelters, using your larger neighbors as cover can become common for reef predators.
