Shedd Aquarium

Zebra Moray Eel Scientific Name: Gymnomuraena zebra

Unlike most other fish, moray eels don’t have scales. So to protect themselves against scrapes and parasites, they ooze a slimy coating of mucus over their thick-skinned bodies.

Region: Philippines

Appearance
Like a snake, the zebra moray eel slithers around coral reefs with its long ribbon-like body that can be up to 5 feet (150 cm) long. Hugging the top and bottom of the body, short wavy fins help propel this moray. As its name suggests, the zebra moray is a dark brown with thin white bands wrapping the body, similar to a zebra. Unlike most other fish, moray eels don’t have scales. So to protect themselves against scrapes and parasites, they ooze a slimy coating of mucus over their thick muscular bodies.

Habitat
Able to slip between corals and other reef creatures, zebra morays are secretive. They slide their long, slimy bodies in and out of reef cracks and crevices, sneaking around rocky seaward coral reefs at depths of 10 to 167 feet (3 to 50 m). Resting during the day, zebras are nocturnal or active at night. They may actually begin their hunt in the twilight hours just before dark. Emerging from the reef, the zebra moray will slither across the sand and into a new reef area in search of food. More zebra morays are hiding in the safe nooks and crannies of the reef rather than are seen out and about.

Range
The zebra moray lives in the warm parts of the Pacific Ocean, Indian Ocean and Red Sea.

Diet
Lurking inside reef crevices, the zebra moray waits, with its head poking out, ready to lunge at unsuspecting prey. Finding prey in the dark is no problem for these eels, thanks to their excellent sense of smell.

When hunting, the zebra moray will nose at its prey with its snout before it attacks. Although crabs are their favorite food of the zebra moray, this fish will also nosh on sea urchins, shrimp and snails. If its prey is small, this moray will chow down on the entire creature at once. With larger prey, the zebra moray will pick off the legs and claws, eat them, and then eat the body. Once the moray has a good grip, prey are locked in. The moray’s teeth face backwards on an angle, pointing toward the throat. This creates a trap that makes it all but impossible for prey to wriggle free.

At rest, a moray breathes through its mouth, flashing a set of numerous teeth. This may make them look mean, but they’re actually breathing—flushing water over their gills. They attack only when hungry or provoked.

Reproduction
Reproduction in moray eels begins with a courtship ritual in the summer months when the water is warmest. Opening their mouths very wide at each other signals the start of this process. Morays will then wrap their bodies around each other for hours. Once the female lays her eggs and the male fertilizes them, the pair leaves one another.

Once hatching from the eggs, the leptocephalus larvae or young moray eels that are shaped like small leaves. They can be about three inches long, very thin, and almost transparent or clear. The larvae float out in epipelagic zone or the zone in the open ocean near the surface for over eight months and when they grow large enough to defend themselves. Then they swim down and join the other creatures on the reef.

Moray eels are known to exhibit three different types of reproductive ability. Some are gonochorists—born either male or female, with only one set of sex organs. Gonochorists do not have the ability to change sex. Other morays are simultaneous hermaphrodites. They have both sex organs and can reproduce with either sex. The zebra moray is a protogynous hermaphrodite, which means it can start its life as a female and then change to the male. Zebra morays have both male and female sex organs. This fish starts its life either as a male or a female, but the females can change sex if there aren’t many males around.

>A species or group of organisms that is in danger of extinction or disappearing from the face of the earth in the near future if its situation is not improved.

A species that can be found throughout its natural range but is declining in number and may become endangered in the absence of special protection efforts.

A species that is not declining in number but is of special concern because it is sensitive to pressure by particular human activities or natural events.

A species that is not declining in number and is not sensitive to pressures by human activities or natural events.

Threats and Management
Moray eels are popular in the pet trade but are only recommended for experienced hobbyists with large home aquariums. Most morays, like the zebra moray, grow much too large for most tanks. They also require lots of caves for hiding. The zebra moray needs to eat live food at least once a week. This can become quite a burden for keepers to go to the pet store each week, and the shrimp and crabs these morays prefer can be costly. Zebra morays are especially hard to keep at home because they may take weeks to months to become comfortable and begin eating in their new surroundings.

Did You Know?
This is a shy, harmless species that won’t bite even if it is being harassed—lbut don’t go and bother it just in case. Divers can swim near this moray, but usually it will back into the reef, hiding from the curious.

Moray eels have very poor eyesight. They mainly rely on their sense of smell to hunt down prey.

References
Web Sites:
NOTE: The following Web sites are not maintained by the John G. Shedd Aquarium and will open in a new browser window.

Fishbase:
http://filaman.uni-kiel.de/Summary/SpeciesSummary.cfm?
ID=7880&genusname=Gymnomuraena&speciesname=zebra

Print Publications:
Debelius, H. 1999. Indian Ocean Reef Guide. Frankfurt, Germany: IKAN. 321p.
ISBN# 3-9317-0267-7.

Hoover, J.P. 1993. Hawaii’s Fishes. A Guide for Snorkelers, Divers and Aquarists. Honolulu, Hawaii: Mutual Publishing. 183p. ISBN# 1-56647-001-3.

Kuiter, R.H. 1998. Photo Guide to Fishes of the Maldives. Australia: Atoll Editions. 257p. ISBN# 1-876410-18-3.

Michael, S.W. 1998. Reef Fishes. Shelburne, Vermont: Microcosm. 624p.
ISBN# 1-890087-21-1.

Myers, R.F. 1999. Micronesian Reef Fishes. Barrigada, Guam: Coral Graphics. 216p.
ISBN# 0-9621564-4-2.

Perrine, D. 1997. Mysteries of the Sea. Lincolnwood, Illinois: Publications International, Ltd. 312p. ISBN# 0-7853-2430-5.

Vocabulary Words

Epipelagic zone – The zone of the open ocean near the surface.

Extinction – An organism that has not been present on the face of the earth for over 50 years.

Gonochorists – Animals that are born either male or female, with only one set of sex organs. Since they only have one set of sex organs, they do not have the ability to change sex.

Leptocephalus larvae – The young moray eel. Shaped like small leaves, about three inches long, very thin, and almost transparent or clear. The larvae float out in epipelagic zone for over eight months and when they grow to a certain size, they swim down and join the other creatures on the reef.

Nocturnal – Active at night.

Pet trade – An industry or business in which animals are taken from the wild and sold to pet stores, zoos, and aquariums.

Protogynous – Starting life as a female then changing into a male.

Hermaphrodite – Having the sexual organs of both male and female; able to produce both egg and sperm.

Organism – A living thing.

Simultaneous hermaphrodites – Animals that have both sex organs and can reproduce with either sex.

Species – A group of organisms capable of breeding and producing fertile offspring; organisms that share the same gene pool.