Zebra Moray, Gymnomuraena zebra
The Zebra Moray, Gymnomuraena zebra, whose common Spanish name is morena cebra, is a member of the Moray and Snake Moray Eel or Muraenidae Family, known collectively as morenas in Mexico. Globally, there is only one species in the genus Gymnomuraena, which is found in Mexican waters of the Pacific and is described here.
The Zebra Morays have robust, elongated, and compressed bodies that taper gradually to a blunt tail. They are covered with a thick yellow mucus. They have a dark red-brown coloration with more than 100 narrow vertical white bands, about 35% of which are broken, that run from the tip of their nose to the tip of their tail and occur about every two centimeters. Their head has a short round snout and a large mouth equipped with flat plate-like teeth utilized for crushing hard shells. Their anal, caudal, and dorsal fins are continuous and extend from before the gill covers on the back to the anus. A unique feature of this eel is their very short tail that measures approximately 33% of total length. They have no pectoral fins, pelvic fins or scales.
The Zebra Morays are a benthic species found in shallow coastal reef environments at depths up to 130 feet. They are slow-growing and reach a maximum length of 1.5 meters (4 feet 11 inches) but are normally half that length. They are found isolated, in pairs or in small schools. They are seen by divers tucked into crevices with only their head exposed. They are very secretive being active nighttime predators that consume crustaceans, mollusks, and sea urchins. They have poor eyesight and a keen sense of smell. They open and close their mouth frequently for respiration. Reproduction has been poorly studied but is believed to occur via protogynous hermaphroditism, whereby females transition to males at midlife. Their eggs are pelagic. They are a poorly studied species and very little is known about their behavior patterns.
The Zebra Morays are widely distributed in the tropical waters of the Indo-Pacific. In Mexican waters, their distribution is limited to the east coast of Baja from Loreto southward to Cabo San Lucas and along the coast of the mainland from Mazatlán southward to Guatemala.
The Zebra Moray is easy to identify thus cannot be confused with any other species.
The Zebra Morays are popular aquarium fish as they are docile and elegant. They require large tanks with crevices for hiding and moderate care. They are known as escape artists. Although visually intimidating, they are actually very timid, will seldom bite humans, and are considered harmless to humans. From a conservation perspective, they have a wide global distribution but have not been evaluated. They are considered at risk due to coral reef degradation and coastal habitat destruction caused by human development.
Zebra Moray Eel, Gymnomuraena zebra. Underwater photo taken in coastal waters off Kailua-Kona, HI, April 2015. Length: 56 cm (22 inches). Photo courtesy of Bob Hillis, Ivins, UT.
Note: I personally have had only one encounter with a Zebra Moray. It was in December 2007, at El Tule Tidal Pools, Km 17, Baja California Sur, and occurred mid-afternoon lasting about 30 minutes. The fish was about 46 cm (18 inches) in length and my objective was to collect him for a photo shoot. He was about 30 feet from the end of tidal slough and I was able to get him with a stick and on dry land for about two minutes at which time he reversed direction and I whiffed with my bait net. He ended up under some large coral rocks and wouldn’t come out. Based on my experiences with live eels in general and due to concerns about getting bitten, which might include poisonous venom, I was unable to convince myself this was a good time to go into hand-to-hand gorilla combat with this guy.