The California moray (''Gymnothorax mordax'') is a
moray eel
Moray eels, or Muraenidae (), are a family of eels whose members are found worldwide. There are approximately 200 species in 15 genera which are almost exclusively marine, but several species are regularly seen in brackish water, and a few are f ...
of the
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Muraenidae
Moray eels, or Muraenidae (), are a family of eels whose members are found worldwide. There are approximately 200 species in 15 genera which are almost exclusively marine, but several species are regularly seen in brackish water, and a few are f ...
, found in the eastern
Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
from just north of
Santa Barbara to Santa Maria Bay in
Baja California
Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...
.
They are the only species of moray eel found off California, and one of the few examples of a subtropical 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.
Habitat and distribution
California morays are a common sight on rocky reefs surrounding islands in southern California (notably,
Catalina Islandin the
California Channel Islands
The Channel Islands () are an eight-island archipelago located within the Southern California Bight in the Pacific Ocean, off the coast of California. The four Northern Channel Islands are part of the Transverse Ranges geologic province, and ...
) and other islands in the Pacific. Their geographic distribution extends from Point Conception, California to Magdalena Bay, Baja California.
California moray juveniles can live in tide pools while adults live in deeper waters.
Adult California morays have high site fidelity, remaining in the same general location throughout their adult lives.
Ecology
Symbiotic relationship
The California moray has a distinct mutualistic symbiotic relationship with
red rock shrimp where the cleaner shrimp clean the moray. The red rock shrimp aggregate in large populations on the moray. In addition to cleaning, the cleaner shrimp help kills parasites within the mouth cavity and have been found to reach the stomach to feed on parasites.
Diet
The California moray is thought to be primarily piscivorous, and appears to specialize in the
kelp bass
''Paralabrax clathratus'', the kelp bass, bull bass or calico bass, is a species of marine ray-finned fish, a sea bass from the subfamily Serraninae, classified as part of the family Serranidae which includes the groupers and anthias. It is foun ...
, Paralabrax clathratus. However, they are opportunistic predators whose diet also consists of invertebrate prey such as octopuses, lobsters, other California morays, and red rock shrimp.
Feeding behavior
The California moray is the apex predator in the reef, its natural habitat, as they have few natural predators and face no intense competition for prey. They are thought to be nocturnal hunters due to their elusiveness in the daytime.
Although many fishes have highly expandable skulls and can use suction feeding to capture prey, the fused skulls of morays prevents this.
Instead, California morays (like other moray eels) have a special set of
pharyngeal jaw
Pharyngeal jaws are a "second set" of jaws contained within an animal's throat, or pharynx, distinct from the primary or oral jaws. They are believed to have originated as modified gill arches, in much the same way as oral jaws. Originally hypo ...
s that allows prey to be transported from their mouths into their throats. These pharyngeal jaws look like miniature versions of the oral jaws and are more mobile than pharyngeal jaws in the other fishes. 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.
Despite the bite force of the California moray varying from 32N and 467N, morays do not exhibit a preference for certain food types based on their relative bite force.
The California moray's prey manipulation behaviors, including consumption and transportation, also do not vary depending on prey type. However, the time spent on prey manipulation behaviors increases as prey size increases. The California moray spends more time feeding as the size of the fish and cephalopods increases. However, when consuming a cephalopod, the California moray spends a greater proportion of time on transportation than feeding. Moreover, prey size increases with the size of the individual California moray. When it comes time for the moray to feed on a cephalopod, like an octopus, the cephalopod will resist by latching on the head of the moray with its tentacles. To counter the cephalopod, the moray will twist and rotate its body so the tentacles can unhinge off the body so the moray can eat the cephalopod. As a California moray grows, its prey becomes larger and it stops consuming smaller organisms.
File:Gymnothorax mordax 1.jpg, California moray
File:Morayeel 300.jpg, California moray
File:CaliforniaMorayEel.jpg, California moray
Behavior
Reproduction
The California moray is believed to mate and spawn in the warm waters off the coast of Baja Mexico, with larvae being transported northward to California during winter or
El Niño Southern Oscillation
EL, El or el may refer to:
Religion
* El (deity), a Semitic word for "God"
People
* EL (rapper) (born 1983), stage name of Elorm Adablah, a Ghanaian rapper and sound engineer
* El DeBarge, music artist
* El Franco Lee (1949–2016), American po ...
events. 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
gonad
A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sper ...
al development. A study used
otolith
An otolith ( grc-gre, ὠτο-, ' ear + , ', a stone), also called statoconium or otoconium or statolith, is a calcium carbonate structure in the saccule or utricle of the inner ear, specifically in the vestibular system of vertebrates. The sa ...
s (ear bones) of California morays from
Catalina Island to estimate individuals' ages, which cross-referenced with data from the Oceanic Niño Index (ONI) and revealed that the majority of individuals examined likely only arrived on Catalina Island due to an
El Niño Southern Oscillation
EL, El or el may refer to:
Religion
* El (deity), a Semitic word for "God"
People
* EL (rapper) (born 1983), stage name of Elorm Adablah, a Ghanaian rapper and sound engineer
* El DeBarge, music artist
* El Franco Lee (1949–2016), American po ...
event.
During an ENSO event, larvae drifted north due to the northward-flowing
Davidson Current. The fertilization of eggs occurs in the water, and although the pelagic larval duration (PLD) of larval ''G. mordax''is is unknown, studies on related species suggest that the larval state persists in the open ocean for several months before settling to reefs.
Threats to humans
Human attacks due to the California moray are very rare but possible when venturing near them. California morays are not venomous, but they have the capability of causing deep puncture wounds with their bite. Injuries can become infected
Conservation
The California moray is classified by the
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
as a species of least concern.
The California moray is not commercially fished, but the species does face threats from pollution and habitat degradation.
However, despite their stability, California morays have still been the subject of conservation efforts. A recent study has connected the conservation efforts in Marine Protected Areas (MPAs) to ecological impacts on California moray populations.
Within MPAs, California morays were found to be longer, older, heavier, had higher body condition, and were found in greater abundance. However, too great of an abundance was also connected to higher frequencies of cannibalism, the presence of disease, and lower growth rates.
References
*
External links
*
{{Taxonbar, from=Q2564511
mordax
Fish described in 1859
Fauna of California