They find for the first time a fish that hides behind others to hunt its prey

2023-08-13 11:22:59

Updated Sunday, August 13, 2023 – 11:22

It is the only known example of a non-human animal using another as a form of concealment.

Specimen of trumpetfish (Aulostomus maculatus).WIKIMEDIA COMMONS

A team of researchers has discovered that the trumpet fish is a “stealthy swimmer” that hides behind others to get closer to its prey. undetected and hunt them down.

This is how they explain it in a study published in the journal ‘Current Biology’. It’s about the first evidence of a marine predator that swims behind another fish before hunting in order to reduce the probability of being spotted by its prey.

The study provides the first experimental evidence that the trumpet fish (‘Aulostomus maculatus’) can hide by swimming behind another fish while hunting, and reduces the probability of being detected by its prey.

In this ‘shadow’ behaviour, the long, slender trumpet fish uses a non-threatening species, such as the parrot fish, as camouflage to get closer to its prey. This is the only known example of a non-human animal using another as a form of concealment.

The investigation involved hours of diving in the Caribbean Sea. “When a trumpet fish swims close to another species of fish, it hides completely from its prey or is seen but not recognized as a predator because the shape is different,” he says. Sam Matchetteresearcher at the Department of Zoological Sciences at the University of Cambridge (United Kingdom).

He damselfish fish (‘Stegastes partitus’) forms colonies on the seabed and is a common meal for trumpet fish. Working among the coral reefs off the Caribbean island of Curaçao, the researchers set up an underwater system to pull 3D-printed models of trumpet fish through damselfish colonies and filmed their responses.

When the model trumpet fish passed by alone, the damselfish swam out to inspect and quickly fled to take refuge in response to predatory threat.

When a model herbivorous parrotfish (‘Sparisoma viride’) passed by alone, the damselfish inspected and responded. a lot less.

When a trumpetfish model was attached to the side of a parrotfish model, to replicate the shadow behavior of real trumpetfish, the damselfish responded just as it had with the parrotfish model alone: it had not detected the threat.

Coral reefs around the world are degrading due to a warming climate, pollution and overfishing. The researchers say that the strategy of hiding behind other moving fish can help animals adapt to the impacts of environmental change.