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By Rosie Clarke
Geographic Range
Distribution ranges from Magdalena Bay, Baja, California, north to Point Conception (Bushing 2000). The population density of the Gymnothorax mordax is greater in southern California with the highest densities in Southern Channel Islands, and Catalina (R.E.E.F. 2000).
Biogeographic Regions:
pacific ocean 
(native ).
Habitat
Inhabits cracks and crevices within rocky reefs in the subtidal zone to 40m (UCLA), but is usually found at 0.6-20m (Eschmeyer 1983).
Aquatic Biomes:
reef .
Physical Description
Gymnothorax mordax has a snake-like body, with no scales or lateral line (Eschmeyer 1983). Coloration is 
light or dark brown, to green, often mottled. Lack of pectoral and pelvic fins distinguishes it from all other eel-like fishes. The California Moray has numerous canine-type teeth that are translucent in the juvenile. A round gill opening is present, however respiration requires the moray to constantly open and close its mouth to push oxygenated water over their gills. A full grown adult can reach up to 152cm or 5ft (UCLA 2000).
Some key physical features:
bilateral symmetry .
Reproduction
Gymnothorax mordax reproduces by external fertilization. Eggs hatch into a specialized planktonic larva called a leptocehalus that eventually settle to the bottom. Juvenile morays can be found in tidal pools, but upon maturation seek deeper water. Very little is know about the leptocephali and juvenile stages of their life cycle, because most specimens found are probably over thiry years old (Eschmeyer 1983). It is hypothesized that the morays off the coast of southern California do not reproduce because the water is too cold. Instead the ocean currents bring the leptocehalali north from Baja California, which then settled out of the upper water column to mature in southern California. The life span of the California moray is speculated to be thirty years or more (UCLA 2000).
Behavior
Gymnothorax mordax has a mutualistic relationship with the red rock shrimp, 
*Lysmata claifornica*. The red rock shrimp clean the moray of dead skin and parasites; in return the moray provides the shrimp with protection by allowing the shrimp to coinhabit the moray's crevice (PBS 2000).
Key behaviors:
natatorial ; motile .
Food Habits
Nocturnal predator on small reef fishes, octopi, shrimp, crabs, lobster, and sea urchins (Bushing 2000). Gymnothorax mordax uses its well developed sense of smell to hunt their prey (PBS 2000).
Economic Importance for Humans: Negative
California moray eels usually won't leave their crevices to attack divers, unless they are aggravated by divers prodding, spearing, or capturing them. Since they do have numerous razor sharp teeth they can inflict serious lacerations on a diver if they do bite (Eschmeyer 1983).
Economic Importance for Humans: Positive
The California moray is popular aesthetic fish among the diving community. Unlike some other eels, Gymnothorax mordax is not poisonous to humans and, therefore, can be eaten (Eschmeyer 1983).
Conservation Status
IUCN Red List: [link]:
Not Evaluated.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
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For More Information
Find Gymnothorax mordax information at
Contributors
Rosie Clarke (author), University of Michigan.
William Fink (editor), University of Michigan.
