One reason why red lionfishes (Pterois volitans) have become so successful invading tropical Atlantic waters may be their unusual hunting technique.
This technique was reported for the first time in a recent issue of the journal Marine Ecology Progress Series.
Mark Albins and Patrick Lyons discovered that the lionfishes blow jets of water at their prey to disorient them, a predatory tactic that has not been previously documented in fishes.
Basing their observations in the field and in the aquarium, the authors discovered that hunting red lionfish faced their prey and gradually approached the fish to within striking distance, while directing a strong, pulsed, jet of water (by compressing their cheeks) at the prey.
Lionfish were observed doing this to cryptic, benthic species such as gobies and blennies, mobile swimmers such as wrasses and parrotfishes, and nocturnal, hole-dwelling species such as cardinalfishes.
Interestingly, lionfish in the Pacific blew water jets at their prey 56% of the time, while those in the Atlantic hunt this way only 18% of the time.
The water jets are thought to overwhelm the lateral line system of prey fishes, increasing the difficulty of detecting the striking predator. They may also make it easier for the lionfish to capture and swallow its prey head first as fish typically face the currents to reduce drag.
The authors hypothesised that this novel hunting method makes lionfish so successful in invading the Atlantic because prey fish there have not encountered this form of hunting before and are unable to take appropriate evasive or defensive measures.
There's also a video showing a lionfish hunting this way.
For more information, see the paper: Albins, MA & PJ Lyons (2012) Invasive red lionfish Pterois volitans blow directed jets of water at prey fish. Marine Ecology Progress Series 448, pp. 1–5.
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