Lionfish reach sexual maturity and reproduce at one to two years old. During courtship, males will aggregate with multiple females with the males using their spines and fins in an aggressive visual display. Females release a pair of mucus coated clusters of eggs which are then fertilized by the males. Larvae hatch after four days and become competent swimmers two to three days after that. In the range of 20-40 days, larvae metamorphose into adults at 10-12 mm/0.4-0.5 inches in size. As juveniles, they live in small groups, but as adults they typically occur alone. The lifespan in the wild is reported up to 15 years.