Moray eels are elongated, serpentine fish found in marine environments worldwide. Over 200 species inhabit tropical and subtropical waters, typically residing in coral reefs, rocky crevices, and other underwater shelters. Their smooth, scaleless bodies often display varied patterns and colors, allowing them to blend into surroundings. Moray eels rely heavily on smell to navigate and hunt, as their eyes are small and vision not highly developed.
Natural Predators
Moray eels, particularly larger species, are often considered apex predators, yet face natural predators. Larger fish, such as groupers and barracudas, prey on them. Certain shark species, including reef and great white sharks, also hunt them.
Predators employ various strategies. Groupers, for example, cooperatively hunt with moray eels, using head-shaking signals to flush out prey from tight crevices. While beneficial, the moray eel can become prey if it attempts to escape. Sea snakes also occasionally prey on them.
Human Interaction
Humans affect moray eel populations. Not a primary commercial fishing target due to unpalatable taste and potential ciguatoxins, they are sometimes caught as bycatch or speared. Consumption of certain species can cause ciguatera fish poisoning.
Human activities also indirectly affect moray eels through habitat destruction and pollution. Coral reef degradation, caused by coastal development, dredging, and climate change-induced coral bleaching, diminishes the caves and crevices moray eels rely on for shelter and hunting. Overfishing of other reef fish can deplete their prey sources. Research suggests moray eels may be more abundant in areas with higher human pressure, possibly due to reduced natural predators and competitors like sharks, which are heavily fished.
Moray Eel Defenses
Moray eels have several adaptations for defense. Their elongated, serpentine bodies allow quick retreat into tight crevices and burrows within coral reefs and rocky areas, making it difficult for larger predators to reach them. This also serves as an ambush point for nocturnal hunting.
A thick, protective mucus layer covers their scaleless skin, helping them slide through confined spaces without injury and providing a barrier against parasites and bacteria. Some species’ mucus contains toxins to deter predators.
Moray eels have powerful jaws and sharp, backward-pointing teeth designed to grasp and tear prey. They uniquely possess a second set of jaws, called pharyngeal jaws, located in their throat. These extend forward to pull prey deeper into their mouth, aiding consumption and defense. When threatened, they may display an aggressive posture, opening their mouths to showcase their teeth.