After colonising parts of the Atlantic on the east coast of the United States and the Caribbean, lionfish are now invading the Mediterranean.
Armed with venomous dorsal spines and fan-shaped pectoral fins, the exotic looking lionfish, a favourite at aquariums, has no known enemies in the Mediterranean.
The reef fish, whose sting is painful but not deadly, is native to the Indian Ocean.
But an outbreak in the Mediterranean has scientists, fishermen and divers so worried that they have launched a campaign to reduce its numbers.
