Green Moray Eel

The Green Moray Eel, Gymnothorax funebris, is a prominent and often encountered species within the family Muraenidae. Despite its common name, this impressive eel is not truly green; its distinctive hue comes from a thick layer of yellowish mucus that covers its dark gray or brown skin, providing protection from parasites and bacteria while creating a green appearance, especially against the dark backdrop of its habitat. As one of the largest moray species in the tropical Atlantic, it can reach lengths of up to 2.5 meters (8.2 ft) and weigh up to 29 kg (65 lbs).

Typically a solitary and nocturnal predator, the Green Moray Eel spends its days concealed within rocky crevices, coral reef formations, or mangrove roots, often with only its head protruding. At night, it emerges to hunt, relying on its keen sense of smell rather than its poor eyesight to locate prey such as fish, crustaceans, and cephalopods. While often perceived as aggressive due to its habit of constantly opening and closing its mouth, this behavior is simply how the eel breathes, pumping water over its gills. The Green Moray Eel is currently listed as "Least Concern" by conservation organizations.

Identification

• Size: These are large eels, commonly reaching 1.5-1.8 meters (5-6 ft) and capable of growing up to a maximum of 2.5 meters (8.2 ft) in length and 29 kg (65 lbs) in weight.
• Coloration: The most striking feature is its apparent green color, which is an optical illusion. The eel's actual skin is dark gray or brown, but it is covered by a protective, thick, yellowish mucus layer that, when combined with the underlying skin color, creates the characteristic green tint. Juveniles are uniformly dark.
• Body Shape: The body is elongated, muscular, and snake-like, with a laterally compressed (flattened side-to-side) form. Its skin is scaleless.
• Fins: Like all true eels, the Green Moray lacks pelvic fins, and like all morays, it also lacks pectoral fins. It possesses a continuous dorsal fin that runs from just behind its head along the entire length of its back, fusing seamlessly with the caudal (tail) and anal fins.
• Head and Mouth: The head features two prominent, tube-like incurrent nostrils on the snout, with the excurrent nostrils appearing as simple openings. Its large mouth is equipped with several rows of sharp, smooth-edged teeth, which are often visible as the eel constantly opens and closes its mouth to respire. The gills are visible as two circular openings located behind the head.
• Habitat: Found in tropical and subtropical waters of the Western Atlantic Ocean, ranging from New Jersey to Bermuda and the northern Gulf of Mexico down to Brazil. They inhabit rocky shorelines, coral reefs, mangrove forests, and occasionally seagrass beds, typically at depths shallower than 30 meters (100 ft), though they can be found down to 40-50 meters (130-164 ft).

Observed at these dive sites:

• Paradise Reef (occasional)
• Tormentos Reef (occasional)
• Columbia Reef (occasional)
• Palancar Reef (occasional)
• Santa Rosa Wall (occasional)
• Maracaibo Deep (occasional)

The Green Moray Eel (Gymnothorax funebris) is a prominent inhabitant of the warm, tropical, and subtropical marine environments across the Western Atlantic Ocean. Its extensive range stretches from New Jersey, USA, southwards to Brazil, encompassing the Gulf of Mexico, the Caribbean Sea, the Bahamas, and the Florida Keys. It is also found in the Eastern Atlantic around Ascension Island, with occasional sightings as far north as Nova Scotia, likely due to oceanic currents.

This species is a benthic and solitary creature, primarily associated with complex underwater structures that offer ample shelter. Divers commonly encounter Green Moray Eels in a variety of ecosystems:

• Coral Reefs: They are frequently observed in vibrant coral reef communities, particularly throughout the Caribbean and Gulf of Mexico, where they utilize the intricate reef structure for hiding.
• Rocky Shorelines and Ledges: Green Morays thrive in areas with rocky shorelines, ledges, and caves, often seen with only their heads protruding from crevices.
• Mangrove Forests: These eels also inhabit mangrove forests and bays, with juveniles often favoring the protective prop root systems of mangroves before transitioning to reef environments as adults.
• Seagrass Beds: Occasionally, they can be found in seagrass beds, utilizing the vegetation for cover.
• Other Habitats: Their adaptable nature also leads them to tidal creeks, harbors, and areas over sandy or muddy bottoms, always seeking out suitable hiding spots.

Green Moray Eels typically reside in shallower waters, most commonly found at depths of 1–30 m. While they generally prefer depths less than 30 m, they have been recorded down to 40 m or even 50 m. They prefer warm tropical waters, generally ranging from 22–28°C. Their reliance on crevices and caves for shelter makes healthy coral reef systems and rocky substrates crucial for their survival, providing ideal ambush points for their nocturnal hunting forays.

The Green Moray Eel (Gymnothorax funebris) is a formidable and captivating inhabitant of Western Atlantic coral reefs, rocky shorelines, and mangroves, frequently observed by divers in regions such as the Gulf of Mexico and the Caribbean Sea.

Underwater Encounter Behavior

During daylight hours, Green Moray Eels are typically sedentary, preferring to remain concealed within rock crevices, caves, or coral structures. Divers will most often encounter them with only their heads protruding from these hiding spots, mouth agape. This characteristic gaping is not a sign of aggression but rather a necessary action to pump water over their gills for respiration. While generally shy and non-aggressive, Green Morays are territorial and will defend their chosen lair. Divers should maintain a respectful distance and avoid provoking them, as a bite can be severe.

Despite their imposing appearance and sharp teeth, Green Morays are not inherently hostile towards humans unless disturbed or threatened. Their vision is relatively poor, and they rely heavily on their acute sense of smell to navigate and locate prey. The vibrant green coloration that gives them their name is actually due to a thick, yellow mucus layer covering their dark grey or brown skin, which also provides protection against parasites and bacteria.

Feeding Habits

The Green Moray Eel is a nocturnal ambush predator. At night, they emerge from their hiding places to actively hunt, relying on their strong sense of smell to detect prey. They are dietary generalists and opportunistic carnivores, feeding primarily on fish, crustaceans (such as crabs and shrimp), and cephalopods (like squid and octopuses). When a Green Moray encounters prey too large to swallow whole, it employs a unique strategy: it wraps its muscular body around the prey in a knot to gain leverage and tear it into smaller, more manageable pieces. They also possess a second set of jaws, known as pharyngeal jaws, which extend forward to grip and pull prey deeper into their throat.

Social Structure

Green Moray Eels are predominantly solitary animals. They are highly territorial, aggressively defending their individual dens and preferred resting areas from other morays. While rare, they may occasionally share dens with other moray species or even sharks, though this does not indicate regular social bonding. Interestingly, Green Morays have been observed engaging in cooperative hunting with other species, such as groupers, where they work together to flush out prey.

Notable Seasonal Patterns

Little is definitively known about the specific reproductive cycles and behaviors of Green Moray Eels in the wild, as their mating habits are rarely observed and they do not reproduce in captivity. However, spawning is believed to occur seasonally, typically during the warmer months, with some sources indicating a breeding season from July to September. During this time, females lay thousands of small eggs (approximately 1 mm in diameter) at a spawning site, which are then externally fertilized by males. There is no parental involvement after fertilization; the eggs float on the surface until they hatch into transparent, ribbon-like larvae called leptocephali. These larvae drift in the plankton for several months (around eight months) before developing into juvenile eels and settling into a suitable habitat.

Green Morays are found in waters typically shallower than 30 m, thriving in tropical and subtropical temperatures. While they do not undertake extensive migrations, their presence at dive sites like Paradise Reef, Tormentos Reef, Columbia Reef, Palancar Reef, Santa Rosa Wall, and Maracaibo Deep remains consistent, though occasional, throughout the year, reflecting their site-specific nature.