Meet the Green Moray Eel
The green moray eel is one of the largest eels in the Atlantic Ocean and a key predator in coral reef ecosystems. Despite its name, the eel is not actually green—its skin is brown, but it is covered in a yellowish mucus that gives it a greenish hue. This slimy coating helps protect the eel from parasites and infections while allowing it to glide effortlessly through tight spaces.
Unlike fish that rely on fins for swimming, moray eels move by undulating their muscular bodies, allowing them to maneuver through coral reefs and rocky crevices with ease. They are often seen resting in caves or within coral structures, exposing only their heads while constantly opening and closing their mouths. While this may appear threatening, it is actually just how they breathe, passing water over their gills to extract oxygen.
Despite their snake-like appearance, moray eels are not venomous, but they do have a powerful bite with sharp, recurved teeth that can hold onto struggling prey. They also possess a second set of jaws, called pharyngeal jaws, which extend forward to help pull prey deeper into their throat—a feature more commonly seen in horror movies than in real life!
Habitat
Green moray eels are bottom-dwelling predators found in shallow to moderately deep waters. They inhabit:
- Coral reefs (especially in the Caribbean and Gulf of Mexico)
- Rocky coastlines and caves
- Seagrass beds and mangroves (which provide excellent hiding spots and hunting grounds)
They typically prefer depths of 10–100 feet (3–30 meters) but can be found much deeper. Since they rely on crevices and caves for shelter, they are highly dependent on healthy coral reef systems, making them vulnerable to habitat degradation.
Lifespan
Green moray eels live an average of 10–30 years in the wild. Their lifespan is influenced by food availability, habitat conditions, and avoidance of predators.
Diet
As ambush predators, green moray eels wait for prey to come close before striking with lightning speed. Their diet consists of:
- Fish (such as grunts, snapper, and parrotfish)
- Crustaceans (crabs, lobsters, and shrimp)
- Cephalopods (squid and octopuses)
Instead of chasing prey, moray eels rely on stealth and patience, using their excellent sense of smell to detect food. Their pharyngeal jaws help secure struggling prey, preventing escape.
Reproduction
Little is known about the reproductive behavior of green moray eels, as they do not reproduce in captivity and their mating habits are rarely observed. However, it is believed that:
- Spawning occurs seasonally, possibly during warmer months.
- Eels reproduce through external fertilization, where females release eggs and males fertilize them in open water.
- Larvae are planktonic for months, drifting in ocean currents before settling into reef habitats as juveniles.
Interesting Facts
- They aren’t really green! Their yellow-tinted mucus makes their brown skin appear green.
- Two sets of jaws! Morays use pharyngeal jaws—a feature found in very few animals—to pull prey deeper into their throat.
- Territorial but shy. They rarely leave their shelters except to hunt and are not aggressive unless provoked.
- They hunt with other species. Green moray eels sometimes team up with groupers to catch prey—a rare example of cooperative hunting in fish.
- They have poor eyesight. Instead, they rely on a highly developed sense of smell to locate prey.
Predators & Natural Threats
Adult green moray eels have few natural predators, but they are sometimes hunted by:
- Large predatory fish (sharks, barracudas, and groupers)
- Other eels (larger moray eels will sometimes eat smaller ones)
Human-Related Threats:
- Habitat Destruction: Coral reef degradation, coastal development, and mangrove deforestation threaten their homes.
- Overfishing: Although not a primary target, green moray eels are sometimes caught as bycatch in fishing nets or speared by divers.
- Pollution & Climate Change: Chemical runoff, plastic pollution, and warming ocean temperatures impact both their habitat and food sources.
Behavior
Green moray eels are solitary, nocturnal, and highly territorial. They spend most of their time hidden in crevices, only emerging at night to hunt.
- Breathing Behavior: They constantly open and close their mouths, which helps pump water over their gills.
- Ambush Predators: They rely on stealth rather than speed, striking at prey with incredible precision.
- Highly Territorial: They defend their burrows aggressively but are not naturally hostile toward humans unless disturbed.
- Mucus-Coated Skin: Their thick mucus layer helps protect them from parasites and infections.
Human Interactions
Green moray eels (Gymnothorax funebris) face increasing threats due to habitat destruction, pollution, overfishing, and climate change.
- Habitat Destruction – Coral reef degradation from coastal development, dredging, and mangrove deforestation is reducing the caves and crevices these eels rely on for shelter. Coral bleaching, caused by warming waters, further destroys their habitat and disrupts the reef ecosystem they depend on.
- Overfishing & Bycatch – Though not a primary target, green moray eels are often caught as bycatch in fishing nets, lobster traps, and longlines. In some areas, they are speared by divers, either for food or out of fear due to their intimidating appearance. Overfishing of reef fish also depletes their prey, making survival more difficult.
- Pollution & Climate Change – Chemical runoff, plastic waste, and rising ocean temperatures pose serious risks. Pollutants in the water can weaken immune systems and contaminate their food sources, while plastic debris can entangle marine life. Ocean warming and acidification harm coral reefs, reducing shelter and prey availability.
As apex reef predators, green moray eels play a crucial role in maintaining marine biodiversity. Protecting coral reefs, enforcing sustainable fishing, and reducing pollution are essential for their survival.
What Can You Do?
As top predators, green moray eels help maintain the delicate balance of reef ecosystems. Without them, populations of smaller fish and crustaceans could surge, disrupting marine food webs. Protecting them means preserving coral reefs, enforcing sustainable fishing regulations, reducing pollution, and expanding marine protected areas. With conservation efforts, we can ensure these fascinating creatures continue to thrive in their underwater world.
Conservation Efforts
While not currently endangered, conservation efforts focus on protecting their habitat and reducing human threats:
- Marine Protected Areas (MPAs) help safeguard coral reefs and prevent overfishing.
- Sustainable fishing regulations help minimize accidental bycatch.
- Coral reef restoration projects help maintain healthy ecosystems for moray eels and other marine life.
- Public education on marine species interactions reduces harmful human encounters.
Protecting coral reefs and reducing pollution is key to ensuring healthy green moray eel populations.
Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Anguilliformes
Family: Muraenidae
Genus: Gymnothorax
Species: G. funebris
