Pelagia noctiluca (Forsskal, 1775) is a jellyfish in the family Pelagiidae. In Latin, pelagia means "of the sea", nocti stands for night and luca means light; thus, Pelagia noctiluca can be described as a marine organism with the ability to glow in the dark. In an unprecedented event on November 21, 2007, a 10-square-mile (26 km2) swarm of P. noctiluca wiped out a 100,000-fish salmon farm in Northern Ireland, causing around £1 million worth of damage.