Goldentail Moray

Goldentail Moray, Gymnothorax miliaris

Goldentail Moray, Gymnothorax miliarisUnderwater photograph taken in coastal waters off Bonaire, December 2019. Photograph courtesy of Bob Hillis, Ivins, Utah. Identification courtesy of H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, California.

The Goldentail Moray, Gymnothorax miliaris, is a member of the Moray and Snake Moray Eel or Muraenidae Family, that is also known as the Bastard Eel and in Mexico as morena manchada. Globally, there are one hundred sixteen species in the genus Gymnothorax, of which eighteen are found in Mexican waters, nine in the Atlantic and nine in the Pacific Ocean.

The Goldentail Moray has a stout, elongated, and compressed body that taper gradually to a rounded tail. They are highly variable in color and can be dark brown in color and covered with numerous yellow dots that are smallest on the head and largest toward the end of the tail where they become irregular and confluent or they can have dark spots on a pale background, or a network of brown lines on a white or yellow background or with a pale body with large irregularly spaced dark blotches. The tip of the tail is pale or yellow. Their head has a short blunt snout with the eyes over the middle of the short mouth that is equipped with short, smooth, slender, conical teeth. Their gill openings are round. 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 the body length. They have no pectoral fins or scales.

The Goldentail Moray is found within coral reefs and rocky structure at depths up to 60 m (200 feet). They reach a maximum of 70 cm (2 feet 4 inches) in length. They are a benthic species that are found as solitary individuals. They are active daytime predators 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. 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. Juveniles are subject to major losses due to predation and few survive to adulthood. The Goldentail Moray is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Goldentail Moray is found is all Mexican waters of the Gulf of Mexico, with the exception that they are absent from coastal waters north of Tampico, Veracruz, and from along the east coast of the Yucatán in the Caribbean.

The Goldtail Moray is is most likely be confused with the Reticulate Moray, Muraena retifera (large black spot on the gill cover).

From a conservation perspective the Goldentail Moray is currently considered to be of Least Concern with stable, widely distributed populations. They are caught as an incidental by-catch with hook-and-line, traps and trawls and sold in local markets for food. They are also a component of the aquarium trade command high prices and are known as notorious escape artists. They are encountered by divers fairly frequently and can be visually intimidating.