The common lionfish feeds on a wide variety of small fish, shrimps and crabs. It hunts primarily at night, stalking and ambushing its prey by spreading the pectoral fins out wide and corralling its prey into a corner, before rapidly swallowing it whole (2) (4) (6) (8).
Although the common lionfish is usually found alone in the non-breeding season, during courtship male lionfish will aggregate with multiple females to form groups of three to eight fish (3) (5), performing a suite of complex courtship and mating behaviours. The elaborate courting display is performed by the male and includes circling, following, and leading the female, as well as using its many spines in territorial displays with competing males (6) (7).
The female lionfish releases two mucus-filled egg clusters (3) (4) (5) (6) (7), each containing between 2,000 and 15,000 eggs, which are fertilised externally by the male (3) (5). The adhesive mucus that binds the clusters together dissolves after several days, releasing the eggs into the water and allowing them to develop as free-floating, planktonic larvae (6) (7). Dispersal of the common lionfish occurs during this pelagic larval phase, during which individual larvae can be travel great distances in the water column (7).
The common lionfish has venom glands positioned at the base of most spines. Used for both predator deterrence and to facilitate prey capture, the spines are encased in a sheath with two grooves that contain venom-producing tissues. When the spines enter the skin of prey or a potential predator, the sheath around the spines is depressed and the tissue releases potent venom into the puncture wound. The venom of the common lionfish contains a neurotoxin which reduces the transmission chemical signals to the muscles, as well as affecting the cardiovascular system (3) (4) (7).