The California moray (Gymnothorax mordax) is a moray eel of the family Muraenidae, found in the eastern Pacific from just north of Santa Barbara to Santa Maria Bay in Baja California. They are the only species of moray eel found off California, and one of the few examples of a temperate moray. They typically occupy boulder or cobble habitats up to 40 m in depth. They can attain lengths of about 5 ft (1.52 m) and are believed to live for upwards of 22–26 years. Like other morays, they have no pelvic or pectoral fins or gill covers.
California morays are a common sight on rocky reefs surrounding islands in southern California (notably, Catalina Island in the California Channel Islands) and other islands in the Pacific. However, at least one study has proposed that this species is non-reproductive in the most northern parts of its range due to the water temperature being too cold for gonadal development. A more recent study aged morays from Catalina Island using their otoliths (ear bones) and found that the majority of individuals examined likely arrived on Catalina Island during an El Nno Southern Oscillation (ENSO) event, supporting the hypothesis that spawning populations are found further south. During an ENSO event, the southward-flowing California Current slows down and moves offshore, allowing the northward-flowing Davidson Current to bring leptocephalus larvae to northern areas.
California morays mainly eat fish, although they are opportunistic predators whose diet also consists of invertebrate prey such as octopuses, lobsters, and shrimp. Interestingly, it appears that California morays will share habitat space with potential prey species, including both shrimp and lobsters. Like other morays, California morays have a special set of pharyngeal jaws that allows prey to be transported from their mouths into their throats. As an additional aid to prey transport, they have a set of depressible teeth in the roof of their mouths that fold upward as prey is swallowed.
No relationship has been found between prey size and moray size, suggesting that California morays will continue to eat small prey even as they themselves get larger. They are apex predators in the reef, with few predators of their own. California morays are not commercially fished.
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