The Tricky Trumpetfish

Trumpetfish like to prey on damselfish and shrimp in coral reefs and seagrass beds, but with 20-inch-long bodies and conspicuously large snouts, they need tricks to hide from their prey. They can change colors to blend into their surroundings or hang vertically alongside soft coral and dart down to suck prey into their gaping mouths. And, as many divers have seen, they swim close alongside another fish, apparently using that body for a shield to ambush prey.

In a study published in Current Biology at the beginning of August, a behavioral ecologist at the University of Cambridge set out with colleagues to see whether they could prove that trumpetfish were genuinely doing something much like that used by duck hunters of old.

To test their hypothesis that the trumpetfish shielding itself was effective, the researchers made 3D-printed models of trumpetfish and parrotfish and operated them on a pulley system near a colony of damselfish on a coral reef off Curaçao. They pulled the fake fish across both together and one at a time. The damselfish spotted the lone trumpetfish model as a threat and retreated into a hole. But the lone parrotfish didn't frighten them. However, when the trumpetfish was pulled alongside the parrotfish, the damselfish did not retreat into its coral head, apparently unaware of the trumpetfish's presence. You can read the full story and see a video here: https://tinyurl.com/2s4tyjtf