The lionfish (Pterois miles), the species targeted in this project, has been reported in multiple regions of the Mediterranean Sea, especially after 2012. The first reports from Cyprus marked the beginning of the uncontrolled invasion that we have been witnessing ever since. Belonging to the family of Scorpaenidae, it is native to Indian Ocean, however owing to its successful invasion in several seas worldwide i.e. Western Atlantic, it has vastly expanded its global distribution. It entered the Western Atlantic via aquarium release in the mid-eighties and displayed one of the fastest and most ecologically harmful marine bioinvasions to date.
Empirical evidence suggests that the lionfish can thrive not only in tropical warm regions but also in subtropical and temperate areas. The Eastern Mediterranean region constantly under non-indigenous species introductions through the Suez Channel combined with sea warming, offer ideal conditions for the lionfish invasion, which seems to be already well underway.
Lionfish are very effective ambush predators and significantly affect the environment they inhabit. As a mesopredator, lionfish has the potential to predate on small native fish and invertebrate species and compete with the native mesopredators. They are characterized as generalist predators as they have been found to consume a large range of species. Initial assessments on feeding ecology in its native range have shown that they exhibit a remarkable feature in their feeding strategy. They can expand the volume of their stomach by 30 times when foraging, allowing them to feed continuously when food is abundant, and being able to tolerate prolonged periods of fastening. This allows them to thrive in areas with low prey availability and consume large quantities of prey when available, a feature that can possibly facilitate their invasion in the oligotrophic waters of Cyprus with seasonal bounties. For example, an increase in lionfish abundance at certain locations in the Western Atlantic coincided with a decline in the biomass of native fish species by up to 95% with the impacts felt over regional scales. Moreover, lionfish were found able to drive an overall shift in invertebrate assemblage composition and mesophotic habitats. The reproductive biology of the P. miles in its native range is not fully understood. Most of the information available has been estimated based on dispersal and known reproductive cycles of the species in invasive populations. Lionfish are gonochronistic species that exhibit a complex courtship before spawning. In Bahamas, they showed to mature after one year and spawn every four days year-round, producing around two million buoyant eggs per year. Pterois miles characteristics such as early maturation and high reproduction rates, pelagic larval phase, anti-predatory venomous defences and ecological versatility make it a ferocious and a rapid invader.