Moray eel

Quality 0.50 · 4 views · Updated 2 months ago

Family of fishes

title: "Moray eel" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["muraenidae", "articles-containing-video-clips", "extant-miocene-first-appearances", "taxa-named-by-constantine-samuel-rafinesque"] description: "Family of fishes" topic_path: "general/muraenidae" source: "https://en.wikipedia.org/wiki/Moray_eel" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Family of fishes ::

| image = Moray_eel.jpg | image_caption = Whitemouth Moray eel in the Maldives | fossil_range = | taxon = Muraenidae | authority = Rafinesque, 1810 | subdivision_ranks = Subfamiles | subdivision = * Muraeninae Rafinesque, 1815

  • Uropterygiinae Fowler, 1925 ::figure[src="https://upload.wikimedia.org/wikipedia/commons/6/6a/Moray_eel.webm" caption="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 found in fresh water.

The English name, moray, dates back to the early 17th century, and is believed to be a derivative from Portuguese moreia, which itself derives from Latin mūrēna, in turn from Greek {{math|μύραινα}}, grk; these are the Latin and Greek names of the Mediterranean moray. : :

Anatomy

The dorsal fin extends from just behind the head along the back and joins seamlessly with the caudal and anal fins, with the exception of the subfamily Uropterygiinae, which have fins restricted to the tip of the tail. Most species lack pectoral and pelvic fins, adding to their serpentine appearance. Their eyes are rather small; morays rely mostly on their highly developed sense of smell, lying in wait to ambush prey.

The body is generally patterned. In some species, the inside of the mouth is also patterned. Their jaws are wide, framing a protruding snout. Most possess large teeth used to tear flesh or grasp slippery prey. A relatively small number of species, for example the snowflake moray (Echidna nebulosa) and zebra moray (Gymnomuraena zebra), primarily feed on crustaceans and other hard-shelled animals, and they have blunt, molar-like teeth suitable for crushing.

Morays secrete a protective mucus over their smooth, scaleless skin, which in some species contains a toxin. They have much thicker skin and high densities of goblet cells in the epidermis that allows mucus to be produced at a higher rate than in other eel species. This allows sand granules to adhere to the sides of their burrows in sand-dwelling morays, thus making the walls of the burrow more permanent due to the glycosylation of mucins in mucus. Placement of their small, circular gills on their flanks, far behind the mouth, requires the moray to maintain a gape / gulping motion to facilitate respiration.

Jaw

::figure[src="https://upload.wikimedia.org/wikipedia/commons/1/1f/GymnothoraxMiliarisCraniumClean.jpg" caption="Skull and pharyngeal jaws of a ''Gymnothorax miliaris'' (goldentail moray)"] ::

The pharyngeal jaws of morays are located farther back in the head and closely resemble the oral jaws (complete with tiny "teeth"). When feeding, morays launch these jaws into the mouth cavity, where they grasp prey and transport it into the throat. Moray eels are the only known animals that use pharyngeal jaws to actively capture and restrain prey in this way.[[File:Pharyngeal jaws of moray eels.svg|thumb|right|270px|Moray eel jaw anatomy|alt=Two diagrams of head and spine, one showing the pharyngeal jaw at rest; the other showing the jaws extended into the mouth]] In addition to the presence of pharyngeal jaws, morays' mouth openings extend far back into the head, compared to fish which feed using suction. In the action of lunging at prey and biting down, water flows out the posterior side of the mouth opening, reducing waves in front of the eel which would otherwise displace prey. Thus, aggressive predation is still possible even with reduced bite times. In at least one species, the California moray (Gymnothorax mordax), teeth in the roof of the mouth are able to fold down as prey slides backwards, thus preventing the teeth from breaking and maintaining a hold on prey as it is transported to the throat.

Differing shapes of the jaw and teeth reflect the respective diets of different species of moray eel. Evolving separately multiple times within the Muraenidae family, short, rounded jaws and molar-like teeth allow durophagous eels (e.g. zebra moray and genus Echidna) to consume crustaceans, while other piscivorous genera of Muraenidae have pointed jaws and longer teeth. These morphological patterns carry over to teeth positioned on the pharyngeal jaw.

Feeding behavior

Morays are opportunistic, carnivorous predators, and feed primarily on smaller fish, crabs and octopuses. A spotted moray eel has been observed eating a red lionfish without harm. Groupers, barracudas and sea snakes are among their few known predators, making many morays (especially the larger species) apex predators in their ecosystems.

Cooperative hunting

Reef-associated roving coral groupers (Plectropomus pessuliferus) have been observed recruiting giant morays to help them hunt. The invitation to hunt is initiated by head-shaking. This style of hunting may allow morays to flush prey from niches not accessible to groupers.

Habitat

::figure[src="https://upload.wikimedia.org/wikipedia/commons/4/4b/Moray_eel_in_Kona.JPG" caption="Kona, Hawaii"] ::

The moray eel can be found in both fresh and saltwater habitats. The vast majority of species are strictly marine, never entering freshwater. Of the few species known to live in freshwater, the most well-known is Gymnothorax polyuranodon. ::figure[src="https://upload.wikimedia.org/wikipedia/commons/d/d8/Spotted_moray_eel.jpg" caption="Echidna nebulosa]]'' occupying a live coral reef, located in Sabang, Philippines"] ::

Within the marine realm, morays are found in shallow water nearshore areas, continental slopes, continental shelves, deep benthic habitats, and mesopelagic zones of the ocean, and in both tropical and temperate environments. Most species are found in tropical or subtropical environments, with only a few species (yellow moray) found in temperate ocean environments.

Although the moray eel can occupy both tropical oceans and temperate oceans, as well as both freshwater and saltwater, the majority of moray eels occupy warm saltwater environments, which contain reefs. Within the tropical oceans and temperate oceans, the moray eel occupies shelters, such as dead patch reefs and coral rubble rocks, and less frequently occupies live coral reefs.

Reproduction and Lifecycle

The reproductive biology of moray eels remains incompletely understood. Most species are oviparous, with external fertilization occurring in the water column. During spawning, both males and females release gametes simultaneously, and the fertilized eggs are subsequently dispersed by ocean currents.

Following fertilization, the eggs develop into leptocephalus larvae, which are transparent and ribbon-like in appearance. These larvae remain in the pelagic zone for extended periods—often up to a year—feeding on microscopic plankton. This prolonged larval phase facilitates wide geographic dispersal prior to settlement in benthic habitats such as coral reefs or rocky substrates, where metamorphosis into juvenile eels occurs.

The transition from larva to juvenile involves significant morphological and behavioral changes, including the development of adult pigmentation, body form, and ecological habits. Juvenile moray eels typically adopt the solitary and territorial behavior characteristic of adults.

Due to their nocturnal activity and the often inaccessible environments in which reproduction occurs, direct observations of moray eel courtship and spawning behavior are rare. Consequently, their reproductive mechanisms remain one of the least documented aspects of their biology.

Environmental factors such as water temperature, photoperiod, and food availability are believed to influence spawning events. Breeding in captivity is infrequent, which further limits opportunities for scientific study of their reproductive cycle.

Taxonomy

::figure[src="https://upload.wikimedia.org/wikipedia/commons/e/e6/Moray4.jpg" caption="Muranidae represented on a phylogenetic tree"] ::

Genera

::figure[src="https://upload.wikimedia.org/wikipedia/commons/9/9a/Gymnomuraena_marmorata_Achilles_172.jpg" caption="A representative structure of the subfamily Uropterygiinae"] ::

There are over 200 known species of moray eels, in 16 genera. These genera are in two sub-families, Muraeninae and Uropterygiinae, which are distinguished by the location of their fins. In Muraeninae the dorsal fin is near the gill slits and runs down the back of the eel, and the anal fin is behind the anus. In Uropterygiinae, both the dorsal and the anal fin are at the end of the tail. Though this distinction can be seen between the two sub-families, there are still many varieties of genera within Muraeninae and Uropterygiinae. Of these, the genus Gymnothorax is by far the broadest, including more than half of the total number of species.

The family Muraenidae comprises the following subfamiles and genera:

File:TakamayuUBf.jpg|Anarchias seychellensis File:FMIB 47184 Gymomuraena vittata, from Cuba.jpeg|Channomuraena vittata File:Echidna nebulosa Réunion.jpg|Snowflake moray (Echidna nebulosa) File:Echida polyzona.jpg|Barred moray (Echidna polyzona) File:FMIB 42381 Enchelynassa vinolentus (Jordan & Evermann).jpeg|Viper moray (Enchelynassa canina) File:Gymnomuraena zebra by NPS.jpg|Zebra moray (Gymnomuraena zebra) File:Laced Moray.jpg|Laced moray (Gymnothorax favagineus) File:Gymnothorax rueppelliae Réunion.JPG|Gymnothorax rueppelliae File:Monopenchelys acuta - pone.0010676.g012.png|Monopenchelys acuta File:Muraena helena swimming v2.jpg|Mediterranean moray (Muraena helena) File:Pseudechidna brummer.jpg|White ribbon eel (Pseudechidna brummeri) File:Ribbon Moray (Rhinomuraena quaesita) (6052858389).jpg|Ribbon eel (Rhinomuraena quaesita) File:Scuticaria tigrina.jpg|Scuticaria tigrina File:Strophidon sathete.jpg|Slender giant moray (Strophidon sathete) File:Uropterygius xanthopterus - 2.JPG|Uropterygius xanthopterus File:Kidako moray.JPG|Kidako moray (Gymnothorax kidako)

Evolution

The moray eel's elongation is due to an increase in the number of vertebrae, rather than a lengthening of each individual vertebra or a substantial decrease in body depth. Vertebrae have been added asynchronously between the pre-tail ("precaudal") and tail ("caudal") regions, unlike other groups of eels such as Ophicthids and Congrids.

Relationship with humans

Aquarium trade

Several moray species are popular among aquarium hobbyists for their hardiness, flexible diets, and disease resistance. The most commonly traded species are the snowflake, zebra and goldentail moray (Gymnothorax miliaris). Several other species are occasionally seen, but are more difficult to obtain and can command a steep price on the market.

Food poisoning

Main article: Ciguatera fish poisoning

Moray eels, particularly the giant moray (Gymnothorax javanicus) and yellow-edged moray (G. flavimarginatus), are known to accumulate high levels of ciguatoxins, unlike other reef fish; if consumed by humans, ciguatera fish poisoning may result. Ciguatera is characterised by neurological, gastrointestinal, and cardiovascular problems that may persist for days after eating tainted fish. In morays, the toxins are most concentrated in the liver. In an especially remarkable instance, 57 people in the Northern Mariana Islands were poisoned after eating just the head and half of a cooked yellow-edged moray. Thus, morays are not recommended for human consumption.

References

References

  1. {{FishBase family. (2009)
  2. {{FishBase. (2010)
  3. (2019-08-16). "Crazy facts about the moray eel".
  4. Randall, J.E.. (2005). "Reef and Shore Fishes of the South Pacific". University of Hawai'i Press.
  5. Fishelson, L.. (September 1996). "Skin morphology and cytology in marine eels adapted to different lifestyles". [[The Anatomical Record]].
  6. (September 2007). "Raptorial jaws in the throat help moray eels swallow large prey". [[Nature (journal).
  7. Hopkin, Michael <!--. (2007-09-05). "Eels imitate ''Alien'': Fearsome fish have protruding jaws in their throats to grab prey". [[Nature News]].
  8. "Moray eels are uniquely equipped to pack big prey into their narrow bodies". U.S. [[National Science Foundation]] (NSF).
  9. (February 2007). "Biting releases constraints on moray eel feeding kinematics". [[The Journal of Experimental Biology]].
  10. (November 2010). "Molecular phylogenetics of moray eels (Muraenidae) demonstrates multiple origins of a shell-crushing jaw (Gymnomuraena, Echidna) and multiple colonizations of the Atlantic Ocean". [[Molecular Phylogenetics and Evolution]].
  11. (January 2009). "Ecomorphology of the moray bite: relationship between dietary extremes and morphological diversity". Physiological and Biochemical Zoology.
  12. (June 2014). "Imperfect morphological convergence: variable changes in cranial structures underlie transitions to durophagy in moray eels". [[The American Naturalist]].
  13. (1989). "Fishes of the Western North Atlantic". Yale University.
  14. Gregory, William K.. (2002). "Fish Skulls: A study of the evolution of natural mechanisms". Krieger Pub.
  15. Kooser, Amanda. "See a snowflake moray eel swallow a sushi snack in an extraordinary way".
  16. (February 2003). "Activity Patterns, Diet, and Shelter Site Use for Two Species of Moray Eels, Gymnothorax moringa and Gymnothorax vicinus, in Belize". Copeia.
  17. (2013). "Predation on Speared Red Lionfish, Pterois Volitans, by Spotted Moray, Gymnothorax Moringa". Florida Scientist.
  18. Weisberger, Mindy. (10 June 2021). "These eels can swallow prey on land, thanks to extendable jaws in their throats".
  19. (2020-07-10). "Moray Eel - Facts and Beyond".
  20. In the December 2006 issue of the journal ''Public Library of Science Biology'', a team of [[biologist]]s announced the discovery of interspecies cooperative hunting involving morays. The biologists, who were engaged in a study of [[Red Sea]] [[cleaner fish]] (fish that enter the mouths of other fish to rid them of parasites), made the discovery.[http://www.livescience.com/animalworld/061207_fish_cooperation.html An Amazing First: Two Species Cooperate to Hunt. LiveScience]
  21. (December 2006). "Interspecific communicative and coordinated hunting between groupers and giant moray eels in the Red Sea". PLOS Biology.
  22. Vail A.L., Manica A., Bshary R., [http://www.nature.com/articles/ncomms2781 Referential gestures in fish collaborative hunting], in Nature Communications, vol. 4, 2013.
  23. (2015). "Distinct habitat selection by freshwater morays in tropical rainforest streams". Ecology of Freshwater Fish.
  24. (2014). "Freshwater habitat use by a moray eel species, Gymnothorax polyuranodon, in Fiji shown by otolith microchemistry". Environmental Biology of Fishes.
  25. (2003). "Activity Patterns, Diet, and Shelter Site Use for Two Species of Moray Eels, Gymnothorax moringa and Gymnothorax vicinus, in Belize". Copeia.
  26. "Moray Eel - Anatomy, Feeding, Behaviour, Reproduction and Types".
  27. "Moray Eel Facts and Habitat | All About Morena Fish Species".
  28. Reece, Joshua. (January 2010). "Phylogenetics and phylogeography of moray eels (Muraenidae)". Washington University Open Scholarship.
  29. {{Cof family
  30. (July 2013). "Evolutionary history of elongation and maximum body length in moray eels (Anguilliformes: Muraenidae)". Biological Journal of the Linnean Society.
  31. (December 2010). "Elongation of the body in eels". Integrative and Comparative Biology.
  32. Maddox, Mike. "Morays!".
  33. (April 2016). "Characteristic Features and Contributory Factors in Fatal Ciguatera Fish Poisoning--Implications for Prevention and Public Education". The American Journal of Tropical Medicine and Hygiene.
  34. (June 2017). "Regional Variations in the Risk and Severity of Ciguatera Caused by Eating Moray Eels". Toxins.
  35. Khlentzos, Constantine T.. (1950-09-01). "Seventeen Cases of Poisoning Due to Ingestion of an Eel, Gymnothorax Flavimarginatus 1". The American Journal of Tropical Medicine and Hygiene.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::

muraenidaearticles-containing-video-clipsextant-miocene-first-appearancestaxa-named-by-constantine-samuel-rafinesque