Spotted Moray

Spotted Moray, Gymnothorax moringa

The Spotted Moray, Gymnothorax moringa, whose common Spanish name is morena manchada, is a member of the Moray and Snake Moray Eel or Muraenidae Family, known collectively as morenas in Mexico. Globally, there are 116 species in the genus Gymnothorax, of which 18 are found in Mexican waters, nine in the Atlantic and nine in the Pacific.

The Spotted Morays have stout, elongated, and compressed bodies that taper gradually to a rounded tail. They are covered with small round overlapping dark brownish to purplish-black spots on a white or pale yellow background. They have a faint black spot covering their gill openings. Their color can vary significantly from location to location. They are covered with thick yellow mucus, which provides them with protection from abrasion. Their head is elongated with a pointed snout and small eyes. Their rear nostrils are comprised of a hole at the lower jaw level when the mouth is closed completely. Their mouth is equipped with canines at the front, a row of five or six outer teeth at the front of their top jaw, a row of three long slender fangs in between, and double rows of teeth. Their top jaw has 14 to 18 pointed teeth plus an inner row of one or two inner teeth at the front. The roof of their mouth has 5 to 11 small teeth. Their well-developed anal and dorsal fins are covered with skin and continuous with the caudal fin. Their dorsal fin originates in front of the gill openings. Their tail is approximately half or slightly greater than half the body length. They have no pectoral fins or scales.

The Spotted Morays are reef-associated and found at depths up to 660 feet. They reach 2.0 meters (6 feet 6 inches) in length and 2.5 kg (5.5 pounds) in weight. They spend the majority of their time hiding in narrow crevices and holes within reef structures with only their head exposed. Their body shape and lack of fins, scales, or gill covers allow them to move quickly in and out of rocky crevices. They are voracious nocturnal ambush predators with poor swimming abilities and poor eyesight that utilize their keen sense of smell to seek out prey, consuming small fish and invertebrates including crab, octopus, and shrimp. In turn they are preyed upon by barracudas, various eels, groupers, and humans. They have small gills and open and close their mouths frequently for respiration. Reproduction is oviparous with eggs and sperm broadcast into the water generating pelagic eggs and larvae that can drift in oceanic currents for up to a year before settling out on the bottom. Each female can release up to 10,000 eggs per annum. Juveniles are subject to major losses due to predation and few survive to adulthood. They are a poorly studied and poorly documented species and very little is known about their behavior patterns.

In Mexican waters, the Spotted Moray Eels are found in all waters of the Atlantic.

The Spotted Moray is most likely be confused with the Purplemouth Moray, Gymnothorax vicinus (gold iris; no spots on head).

The Spotted Morays are retained by subsistence fishermen and sold fresh and salted on a limited basis in local markets. They are utilized by the aquarium trade on a nominal basis but become large, highly predatory, and unmanageable fairly quickly. They are also notorious escape artists. Visually they are most intimidating and are known to be highly aggressive towards intruders of their home territory. They can also attack and bite humans causing painful bacterial infections. From a conservation perspective, they are widely distributed and locally abundant, thus currently considered of Least Concern.

Spotted Moray, Gymnothorax moringa. Fish caught from coastal waters of the Florida Keys, Florida, January 2017. Length: 60 cm (24 inches). Catch, photo, and identification courtesy of Josh Leisen (lifelistfishing.com), Gaylord, MI.