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Moray eels are large cosmopolitan eels of the family Muraenidae. There are approximately 200 species in 15 genera. The typical length of a moray is Template:Convert. The longest is the slender giant moray, Strophidon sathete, at up to Template:Convert. The largest in terms of total mass is the Giant moray (Gymnothorax javanicus), which reaches almost Template:Convert and can weigh over Template:Convert.

Anatomy

File:Muraena helena.2 - Aquarium Finisterrae edit.JPG

Muraena helena showing typical moray eel morphology: robust anguilliform shape, lack of pectoral fins and circular gill openings

The dorsal fin extends from just behind the head along the back and joins seamlessly with the caudal and anal fins. Most species lack pectoral and pelvic fins, adding to their snake-like appearance. Their eyes are rather small; morays rely on their highly developed sense of smell, lying in wait to ambush prey.

The body is generally patterned. Camouflage is also present inside the mouth. Their jaws are wide, framing a protruding snout. They possess large teeth, designed to tear flesh as opposed to holding or chewing.

File:Pharyngeal jaws of moray eels.svg

Moray eel jaw anatomy


Moray eels' heads are too narrow to create the negative pressure that most fish use to swallow prey.  Quite possibly because of this, they have a second set of jaws in their throat called pharyngeal jaws, which also possess teeth. When feeding, morays launch these jaws into the mouth, where they grasp prey and transport it into the throat and  digestive system. Moray eels are the only  animal that uses pharyngeal jaws to actively capture and restrain prey.<ref name="Mehta2007">
{{cite journal
| last =Mehtal | first =Rita S.
| authorlink =Rita Mehtal
| coauthors =Peter C. Wainwright
| title =Raptorial jaws in the throat help moray eels swallow large prey
| journal =Nature(journal)
| volume =449
| pages =79–82
| date =2007-09-06
| url =http://www.nature.com/nature/journal/v449/n7158/abs/nature06062.html
| doi =10.1038/nature06062
| accessdate =2007-09-06
}}</ref><ref name="Nature20070905">{{cite web
| last =Hopkin | first =Michael
| authorlink =Michael Hopkin
| title =Eels imitate alien: Fearsome fish have protruding jaws in their throats to grab prey.
| work =News
| publisher =Nature.com
| date =2007-09-05
| url =http://www.nature.com/news/2007/070903/full/070903-11.html
| doi =10.1038/news070903-11
| accessdate =2007-09-06
}}</ref><ref>National Science Foundation(Sep. 5, 2007)</ref>Larger morays are capable of seriously wounding humans.

Morays secrete a protective mucus over their smooth, scaleless skin which in some species contains a toxin. Morays 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<ref>{{cite journal
|author=Fishelson L
|title=Skin morphology and cytology in marine eels adapted to different lifestyles
|journal=Anat Rec.
|volume=246
|issue=1
|pages=15–29
|year=1996 |month=September
|pmid=8876820
|doi=10.1002/(SICI)1097-0185(199609)246:1<15::AID-AR3>3.0.CO;2-E }}</ref>, thus making the walls of the burrow more permanent due to the glycosylation of mucins in mucus.  Their small circular gills, located on the flanks far posterior to the mouth, require the moray to maintain a gap in order to facilitate respiration.

Morays are carnivorous and feed primarily on other fish, cephalopods, mollusks, and crustaceans. Groupers, other morays, and barracudas are among their few predators.  There is a commercial fishery for several species, but some  cause ciguatera fish poisoning. Morays hide in reef crevices until their prey is close enough for capture. They then lunge out and clamp the prey in their strong jaws.

Behavior

File:Lysmata amboinensis cleans mouth of a Moray eel.jpg

A Pacific cleaner shrimp cleans the mouth of a moray eel.


Hunting

File:Ribbon eel.jpg

Ribbon moray,<br />Rhinomuraena quaesita


A species of reef-associated grouper, the roving coral grouper (Plectropomus pessuliferus), often recruits morays to aid them while hunting for food. This is the only known instance of interspecies cooperation among fish.<ref>In the December 2006 issue of the journal Public Library of Science Biology, a team of biologists 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.An Amazing First: Two Species Cooperate to Hunt | LiveScience<!-- Bot generated title --></ref><ref name=Bshary>Template:Cite journal</ref>

File:Gymnothorax fimbriatus.JPG

Fimbriated moray,<br />Gymnothorax fimbriatus

Reputation

The Morays have sometimes been described as vicious or ill-tempered.  Morays hide from humans and would rather flee than fight. Morays are shy and secretive, and attack humans only in self-defense. Most attacks involve accidental bites during human initiated interaction. Morays cannot see or hear very well and rely mostly on their acute sense of smell. Morays, however, do inflict a nasty bite, because, although not poisonous, their backward-pointing teeth are covered with bacteria which may infect the wound.

Eels that have eaten certain types of toxic algae or fish that have eaten some of these algae, they can cause ciguatera fish poisoning if eaten.  Large morays can also cause extreme physical trauma, in some cases amputating a diver's finger.  Morays rest in crevices during the day and hunt nocturnally, although they may ensnare small fish and crustaceans that pass near them during the day.<ref name=Bshary/>Template:Clearleft


== Habitat ==Moray eels are cosmopolitan, found in tropical and temperate seas, although they prefer subtropical coral reefs in warm waters. They live at depths up to Template:Convert, where they spend most of their time concealed inside crevices and alcoves. Echidna rhodochilus, commonly called the Freshwater Moray Eel live in colder waters to depths of Template:Convert, are found in the northern United States Great Lakes and Eastern Thailand, where they spend most of their time in sand block alcoves.

 Genera

File:Moray eel kona.jpg

Whitemouth moray, Gymnothorax meleagris


* Subfamily Muraeninae
** Cirrimaxilla
** Echidna
** Enchelycore
** Enchelynassa
** Gymnomuraena
** Gymnothorax
** Monopenchelys
** Muraena
** Pseudechidna
** Rhinomuraena
** Scuticaria
* Subfamily Uropteryginae
** Anarchias
** Channomuraena** Uropterygius

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