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FAQs on: Dragon Moray Eels 1, Dragon Morays 2,

FAQs on: Dragon Moray Identification, Dragon Moray Behavior, Dragon Moray Compatibility, Dragon Moray Stocking/Selection, Dragon Moray Systems, Dragon Moray Feeding, Dragon Moray Health, Dragon Moray Reproduction,

Related FAQs: Snowflake Morays, Snowflake Morays 2, Snowflake Eel Identification, Snowflake Eel Behavior, Snowflake Eel Compatibility, Snowflake Eel Selection, Snowflake Eel Systems, Snowflake Eel Feeding, Snowflake Eel Disease/Health, Snowflake Eel Reproduction, Moray Eels in General, Moray Behavior, Moray Compatibility, Moray Selection, Moray Systems, Moray Feeding, Moray Disease, Moray Reproduction, Freshwater Moray Eels, Zebra Moray Eels, Other Marine Eels,

Related Articles: Moray Eels, Non-Moray Marine Eels, Zebra Moray,

The Hawaiian (and elsewhere) Dragon Eel Enchelycore pardalis
Verticals (Full/Cover Page Sizes Available)

By Marco Lichtenberger

Introduction

The moray eel family (Muraenidae) contains quite a number of extraordinary fishes from the tiny yellow Dwarf moray (Gymnothorax melatremus) to the impressive Tesselata eel (Gymnothorax favagineus). Some eels command high prices in trade, not because they are exceptionally rare in nature, but also because the young are often very secretive, difficult to catch and because the transport of larger animals is more expensive. Sometimes the reputation of a species as a status symbol may also be related to its pricing. Aside that, the Hawaiian dragon eel Enchelycore pardalis has a number of characteristics interesting to hobbyists as well as divers and photographers: A fierce look with long pointed teeth and a long snout that cannot even be closed completely apparently due to the teeth. Very few other moray eels exhibit orange and red colors, and none does in such intensity.

Enchelycore pardalis reaches up to 3 feet (92 cm). The funny looking tubes above their eyes reminding of dragon horns are simply their rear nasal tubes. Water enters the eel at the shorter frontal nasal tubes on the tip of the snout, streams through channels with large folded surfaces for smell and leaves through the rear tubes. This structure explains why eels have such a good sense of smell. The rest of the features is pretty much moray eel standard. A long muscular body, a think slimy skin, a fin seam and no extra fins, which makes them not the best of swimmers, but perfectly adapted to a life predominately in cracks and crevices of rocky and coral reefs.

Picture by Marylka Yoe Uusisaari
http://www.flickr.com/photos/marylkayoe/
3891730220/
Picture by Loretta Todd
http://www.flickr.com/photos/stanfam/
4740977295

Japanese and Hawaiian Dragon eels

Enchelycore pardalis occurs in many parts of the tropical Indo-Pacific. The species can be found from the West of the Indian Ocean around the island of Réunion to Hawaii in the East and from Southern Japan and South Korea down to Line, Society and New Caledonia in the Southern Pacific. It appears to be quite rare in most of these areas, maybe with the exception of Hawaii and rocky areas between the Northern Philippines and southernmost Japan, where it lives in subtropical to tropical waters. Specimens are hardly imported from other areas. Therefore, the common names 'Japanese Dragon eel' and 'Hawaiian Dragon eel' are used in trade to indicate where specific eels come from. This has also led to the misconception that there are two different species. All Japanese and Hawaiian dragon eels at the current state of knowledge belong to one species: Enchelycore pardalis.

Potential differences in coloration of specimens from the two different regions are not well reproducible. You can find both pale and colorful individuals around Hawaii and South of Japan. The amount of red, orange, black and white as well as the size of the white spots can also differ with age, possibly even the habitat (this is known for another morays such as Gymnothorax favagineus, Gymnothorax pictus). If you expect a definite answer on how to differentiate between Hawaiian and Japanese specimens, you probably will be disappointed. Feel free to compare diver pictures with given locations (e.g. flickr) as well as pictures from scientific literature and fishbase yourself. However, be careful with pictures from the pet fish trade.

The Hawaiian dragon eel's species name 'pardalis' is a reference to the panther or leopard. Especially outside of the aquarium trade you'll find the common name 'Leopard moray' used in literature for this species. However, this common name is also used for other species such as the Tessellated moray (Gymnothorax favagineus) or Gymnothorax polyuranodon, with the latter being the only one showing a coloration very similar to the big cat.

Picture by Tabitha Borchardt
http://www.flickr.com/photos/mookmonkey/
5166717493
Picture by Klaus Stiefel
http://www.flickr.com/photos/pacificklaus/
3894864669

Using the term 'Dragon moray' without reference to a location can also easily lead to misunderstandings, since several members of the genus Muraena, which possess comparable hornlike rear nasal tubes have also been called 'Dragon moray'. The common name 'Brazilian dragon eel' has been used for Muraena pavonina, Muraena melanotis and Muraena retifera (although the latter does not occur in Brazil). Muraena melanotis is also called 'African dragon eel' and Muraena lentiginosa is known as the 'Mexican dragon eel'.

Consequently the use of the scientific name Enchelycore pardalis in general is most helpful, but in this specific case 'Japanese Dragon eel' and 'Hawaiian Dragon eel' are also pretty much unambiguous.

A lot of older literature puts this species into the genus Muraena (making the complete name Muraena pardalis) and indeed it does have a few characters in common with Muraena species, especially the hornlike elongated rear nasal tubes mentioned above and the skin structure on top of the head. The elongated rear nasal tubes are not present on other Enchelycore species. What makes the Hawaiian dragon eel superficially similar to other Enchelycore spp. are its slender and curved jaws that cannot completely close and the very long teeth. Two other synonyms of this species are Muraena kailuae and Muraena lampra.

Males and females

Sometimes Enchelycore pardalis can be seen as pairs in nature as well as in tanks. It is well possible, but not eventually necessary that these pairs consist of a male and a female. If such 'mated pairs' are acquired from the pet shop chances are high that these eels will also get along fine in an aquarium.

*Suggested position of pictures 2 and 3*

Picture by Kent Smith
http://www.flickr.com/photos/kentsmith9/
4089068752/in/set-72157622765948438
Picture by Zheng Yingjie
http://www.flickr.com/photos/zzzyjj/
5083716752

One topic you'll eventually stumble over when researching Hawaiian dragon eels is how to sex these eels. There is quite a number of people claiming to be able to do that given various morphological or chromatic features (e.g. 'males have more orange on head and neck and a more stippled pattern on the body', see in Michael, 1998), some saying they just know it without being able to formulate more specific guidelines.

Most interestingly all these claims to my knowledge have never been substantiated by production of fertilized eggs or alternatively dissection and examination of perished animals, leaving it unknown until now if members of this species can be sexed and which ones are the females and which ones are the males. The fact that quite a number of moray species can change their gender or apparently occur as simultaneous hermaphrodites makes the usability of genetic methods and even the evaluation of possible, fertilized eggs pretty much doubtful.

It can be concluded that so far no method is known to me to sex this specific moray eel species, while some other species can be sexed by their dentition e.g. Snowflake morays (Echidna nebulosa), Barred morays (Echidna polyzona) and Gymnothorax richardsonii or at least in nature apparently by colour (Rhinomuraena quaesita).

However, if you want to sell a 1.000 $ fish or enjoy showing it off pulling some mystic information about the gender out of your hat is certainly more impressive than admitting 'I don't know' or saying 'Based on '� I have an assumption, but'�'. Consequently, just like other morays, they have not been reproduced in captivity.

Life in nature

Similar to most morays this species leads a nocturnal and secretive life and likely most specimens, especially smaller and therefore more vulnerable ones, are not seen by divers at all. Michael (1998) noted that this species is often found in Porites compressa corals. Sometimes two Hawaiian dragon eels can be found sharing the same hideout, rarely they are seen with other eels nearby such as Gymnothorax kidako in the Southern Japan area.

The few cases where stomach contents have been examined indicate that this eel mostly consumes other fishes. Very likely Crustaceans and Cephalopods (especially octopuses) are also eaten.

Picture by Lordhowensis
http://www.flickr.com/photos/lordhowensis/
5147860644
Picture by lelliebunny
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3492652242

Captive care

Enchelycore pardalis reaches a length of about 3 feet (92 cm) and at this length has a greater girth than many other moray eels. They become easily as thick as a male lower arm with age.

I'd consider a 125 gallon tank as the reasonable bare minimum for a single specimen. For long term care both the keeper and the fish would probably be more happy with a tank larger than 200 gallons. Especially, if you want to keep this eel with various corals or other compatible invertebrates the dilution and filtration of the larger system will be very beneficial. For a second eel, add at least 50% of tank size (preferably 100%).

Other useful things to know when keeping Hawaiian dragon eels are:

- Keep the tank closed (lid, net, very high frames have worked for at least some). Otherwise, the curious eel may decide to explore the outside of its new home.

- They do well at standard marine aquarium temperatures (76-80 F, 24-27°C), but can also be kept up to 2-3°C colder if the other organisms in the respective tank also live at these temperatures.

- Provide enough caves: You can use simple live rock constructions, but my advice is fix them either with appropriate glue or concrete, or at least with cable wraps. A non fixed composition will be destroyed at some point by an eel of this size and you will have rocks tumbling around in your (likely glass) tank. In extreme cases and heavy rocks even the eel might get hurt. Personally I incorporate PVC pipes in all tanks for medium sized to larger moray eels. Offer at least 2 or 3 caves per eel.

- Feed a varied diet. Use mostly fillet of a variation of marine fishes. If you have them available you can also feed heads and tails as well. Additions are shrimps and other crustaceans as well as octopus, squid and calamari. If you feed mostly frozen food, add vitamins about one time per week to avoid vitamin deficiency diseases. Younger Dragon eels can be fed 3 times a week, for larger ones 1 meal per week can be sufficient. A meal should be about as large as the entire head of the eel. If you prefer daily feedings, decrease the size of the ration accordingly.

- Provide enough oxygen. A strong skimmer and surface movement with stream or powerhead pumps will help with the gaseous exchange of tank water and air.

- Keep the water clean. PH should be between about 8.0 and 8.4, nitrates below 20-25 ppm and nitrites and ammonia should never occur in measurable concentrations (hobby test kits that is).

*Suggested position of pictures 5 and 10*

Picture by Mr. Lobos
http://www.flickr.com/photos/
24660510@N07/4974194903
Picture by Ryan DeLuca
http://www.flickr.com/photos/ryno
720/4667696255

Compatibility

I recommend a specimen tank. There have been numerous attempts to keep these eels with other fishes by various keepers. While this works sometimes for months or even years especially with groupers or other stout tank mates, most fishes, which can be eaten are eaten at some point. Even fishes too large to be eaten, can be bitten badly. Some had limited success with very small and fast fishes that in general are not worth the trouble of hunting them for the moray such as Chromis, but you may see them vanishing one by one.

Basically Hawaiian dragon eels can be kept with other moray eels of the same or preferably slightly larger size in sufficient tanks with enough caves, but there are also cases where this has gone wrong. It depends mostly on the individuals you put together and prognosis can hardly be given.

Lysmata Cleaner shrimps, even Stenopus spp. can work, especially if they have been added before the eel, but after all there's no guarantee they won't be eaten. If they are not, however, a Dragon eel cleaned by a bunch of cleaners is an interesting sight for sure.|

Diseases

Enchelycore pardalis can reach ages of more than 17, probably more than 20 years. Given a proper environment (clean water, little stress) and a varied diet, these hardy animals rarely get sick. They are almost never affected by protozoan diseases such as Whitespot ('Ich', Cryptocaryon) or Velvet (Amyloodinium), but can be infected by bacterial diseases, especially in a not-so-prefect environment or with a weak immune system. This is best prevented by an adequate environment and proper diet as noted above.

Sometimes dragon eels will stop feeding. This can be related to stress (moving, inadequate tank mates), bad water quality or simply overfeeding in the months before. A healthy eel can go without food for a few months and as long as the water quality is fine and no further symptoms occur a fasting Dragon eel is no reason for concern.

Résumé

Dragon eels can be very interesting animals to keep, they command a high price and need a well planned and filtered tank as well as a proper diet to lead a healthy life. Smile about some of the myths spread in the hobby and enjoy them at home, in the zoo and the ocean.

Literature

Lichtenberger, M. (2008): Muränen im Meerwasseraquarium (moray eels in the marine aquarium).- 64 p., Natur und Tier Verlag, Münster (in German).

Michael, S.W. (1998): Reef fishes vol. 1.- 624 p., TFH Publications.

Purser, P. (2005): Moray Eels in the Aquarium.- TFH Publications.

Randall, J.E. (2005): Reef and shore fishes of the South Pacific: New Caledonia to Tahiti and the Pitcairn Islands. University of Hawai'i Press. 707 p.

Randall, J.E. (2007): Reef and shore fishes of the Hawaiian Islands. University of Hawai'i Press. 546 p.

 

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