Picture of a Pregnant Cleaner Shrimp inside Giant Moray
The giant moray (Gymnothorax javanicus) is carnivorous and nocturnal, hunting its prey within the reef. It is known to engage in cooperative hunting with the roving coral grouper. These two fish species are complementary hunters: While the eel hunts in the reef, it may scare prey up and out of the reef, leaving them to be eaten by the grouper. Similarly, the grouper hunting above the reef may cause prey to attempt to seek refuge in the reef, where the moray may ambush them.
The giant moray mainly feeds on fish and occasionally on crustaceans. This moray eel was recently identified as natural predator of the lionfish (Pterois miles) in its native habitat in the Red Sea. A mature giant moray has few natural predators, although it may compete for food with reef-dwelling sharks. Cleaner wrasses and cleaner shrimps (Urocaridella antonbruunii) are commonly found in its presence, cleaning the interior of its mouth as you can see in this Picture.