An experiment on coral reefs provides the first evidence that predators use other animals for motion camouflage to approach their prey without detection.
The trumpetfish, with its long, slender body, shadows non-threatening species like the parrotfish. This allows it to get closer to its prey, such as damselfish, without being detected. Dr Sam Matchette, a leading researcher from the University of Cambridge, explains that when the trumpetfish swims alongside another species, it either remains hidden or is not recognised as a threat due to its altered shape.
Research conducted in the Caribbean Sea involved using 3D-printed models of trumpetfish and observing the reactions of damselfish colonies. When the trumpetfish model was shadowing a model of a herbivorous parrotfish, the damselfish did not detect the predatory threat, showcasing the effectiveness of this camouflage strategy.
With coral reefs globally facing threats like climate change and overfishing, the trumpetfish's shadowing behaviour might be an adaptive response. Dr James Herbert-Read from the University of Cambridge suggests that as reef structures diminish, this stealthy approach could become more prevalent.
This study, a collaboration between the University of Cambridge and the University of Bristol, highlights the innovative ways marine life adapts to environmental challenges. The trumpetfish's shadowing behaviour offers a fascinating glimpse into the intricate dynamics of underwater ecosystems.
What is motion camouflage?
Motion camouflage is a dynamic form of concealment employed by certain animals during movement. Instead of remaining stationary or blending into their surroundings, these animals move in such a way that they appear stationary to their target, despite getting closer. This is achieved by maintaining a consistent angle between themselves and their target during approach.
Predators use this tactic to stealthily approach prey, while some species use it to avoid detection by predators. The strategy minimizes the apparent motion of the camouflaging animal relative to the target, allowing for a covert approach.