Trumpetfish are known for their preference for damselfish and shrimp as prey in coral reefs and sea grass beds. However, due to their 20-inch long bodies and large snouts, they need to employ strategies to sneak up on their targets. A recent study published in the journal Current Biology revealed that one effective strategy used by trumpetfish is to hide behind larger, nonpredatory fish. This deceptive behavior has intrigued scientists, leading them to wonder if other species may also be utilizing similar hunting tactics.
While some coral reef residents, like groupers and moray eels, cooperate when hunting for mutual benefit, the trumpetfish appears to employ its sneaky shadowing technique solely for its own advantage. However, this is not the only method the trumpetfish employs to catch prey off guard. It is also capable of changing color to blend into its surroundings, camouflaging as inanimate objects like sticks or seaweed, and attacking from above by hanging vertically in the water column and swiftly diving to consume its prey.
The hiding behind larger nonpredatory fish, such as parrotfish, until prey is within striking range seems to be one of the trumpetfish’s preferred hunting strategies. This behavior has been observed and documented in guidebooks, dive blogs, and previous research. The similarities to the strategy employed by human hunters to approach waterfowl, known as “stalking horse,” intrigued researchers. In the past, hunters used horses or cattle as stalking horses to hide from ducks and prevent them from being spooked. Today, hunters use blinds and cardboard cutouts for the same purpose.
To investigate if trumpetfish truly employ a similar strategy, the researchers created 3D-printed models of trumpetfish and parrotfish. These models were attached to a wire pulley system near a colony of damselfish on a coral reef off Curaçao. The researchers then filmed the reaction of the damselfish as they pulled the fake fish models along the wire, both together and individually. The results showed that when the trumpetfish model was pulled, the damselfish perceived it as a threat and quickly fled. However, when presented with the parrotfish model, the damselfish simply inspected it without any significant reaction. Additionally, when the trumpetfish model was attached to the side of the parrotfish model and pulled past the damselfish, the fish did not flee.
This experiment demonstrated the clear advantage that the stalking horse strategy gives to trumpetfish, confirming what fish biologists have long suspected. Luiz Rocha, the curator of ichthyology at the California Academy of Sciences, believes that this strategy is likely used by many other nonhuman animals as well. Dr. Matchette, the author of the study, also agrees, suggesting that there are more examples of this behavior yet to be discovered.
Furthermore, Dr. Matchette proposed that as coral reefs degrade due to climate change, the stalking horse behavior may become more prevalent. With fewer corals available for hiding, predators on the reef may increasingly rely on using larger neighbors as cover. Overall, the study sheds light on the clever strategies employed by trumpetfish and raises intriguing questions about the prevalence of similar hunting tactics in other species.