Green moray eel

Photo: terence zahner · CC BY-NC

The green moray is the largest moray eel in the Atlantic, reaching up to 2.5 metres. Their apparent green colouration is actually yellow skin covered by a greenish mucus that provides protection against bacteria in their crevice-dwelling lifestyle. They are primarily nocturnal predators of fish, octopus, and crustaceans, though divers regularly spot them at wreck sites during daylight hours. Their jaw-opening behaviour — constantly opening and closing to pump water over their gills — looks threatening but is simply the moray's method of breathing. Ecologically vital as reef predators that control fish populations.