Atlantic Chain Moray Eel

The Chain Moray Eel is listed as the 3rd most suitable eel to keep with fish, and each eel has it’s own unique pattern!

Chain Moray Eels have an overall color that is white to yellow with mottling that is black, brown or gray.  Juveniles have less markings than adults and each individual eel has a unique pattern.  The Chain Moray have one continuous dorsal fin and a continuous pelvic fin.  They lack scales, have flexible gill coverings, and taste buds on their nose and mouth.  The Chain Moray have blunt molar shaped teeth used for masticating crustaceans.  They have an excellent sense of smell, with 2 tube like appendages on their nose and two holes at the top of their head.   This amazing ability makes up for their smaller eyes and poor vision.   These crustacean eaters have shorter heads and mouths and grow up to 28” (71 cm), though some Chain Moray Eels are known to grow longer in captivity.  Chain Moray Eels can be kept by intermediate aquarists, since beginners typically do not have very large tanks, and the fact that long term survivability of this eel is dependent on live foods.

All morays, just by innocently respirating, or breathing can look very mean. They are simply pulling water down their mouths and out of the back of their gils which is done by opening and closing their mouths.  The Chain Moray takes 1.5 to 4 minutes to break up and eat a crab that is 2 to 3 times larger than the eel’s head width!  This is done by rotating, tugging, knotting and thrashing to break it up into smaller pieces; while smaller crabs are eaten  whole.  Morays are commonly followed by other fish as they hunt.  Those smart fish know that the eel will flush out fish hiding in the reef.  Those fish are usually lionfish, groupers, soapfish or goatfish.  Just FYI, if you find your eel dried up on the floor, quickly put them back in the tank, since they shed their outer slime cover to protect themselves.  Be patient since this can take several hours for them to revive!  They produce a copious amount of body slime, which can tax the filtration on a tank that is too small.

Although morays are very hardy, the challenge with the Chain Moray, is in the long term.  According to one source, Thresher, 1980, he states that these eels seem to need live foods to sustain them long term, because they are less likely to eat enough wihtout live foods.  Feed them small fiddler crabs, Sally Lightfoot Crabs, hermit crabs and glass shrimp along with chunks of crab flesh from saltwater sources.  Overfeeding eels can cause fatty deposits on the liver or can cause it to regurgitate it’s meal, making a total mess of the water in the tank!  The Chain Moray only eats every 3 to 4 days, but feed to satiation.  Make sure rock work is secured with cable ties, non-toxic zip ties or another means, and be sure the rocks are sitting directly on the bottom of the tank, not on top of sand.  Do not use decorations made of fiberglass, since it will cause sores to form on their skin.  Due to their lace of scales, do not use medications that have copper or organophospates (masoten, dylox, Dipterex, Neguvon, and Malathion).  

The group of eels which the Chain Moray is associated with, are called Pebbletooth Morays.  These eels are equipped with molar shaped teeth, used to crush crustaceans…. crush crustaceans, there is a tongue twister!  Keeping that in mind, crabs would be fair game.  They will eat cleaner wrasses on occasion in the wild, but more often in captivity.  Cleaner shrimps are not usually eaten if they were in the tank before the eel.  Fish tank mates are not typically sought after as food, but when there is a food source present, these eels, with their very sensitive smell, but poor eyesight, will start snapping at anything it bumps into, including fish, as they “pursue” their prey.  To keep this to a minimum, train them to take chunks of crab flesh from a feeding stick where they hide out.  They can learn to wait for food, which will helps prevent the feeding frenzy behavior that tends to take out innocent fish!  Morays will not bother corals, but their movements can topple unsecured corals.  Fish known to eat the Chain Moray are the Mutton Hamlet (Alphestes afer), the Red Grouper (Epinephelus morio), the Nassau Grouper, (E. striatus), and the Schoolmaster Snapper (Lutjanus apodus); all of which are found in the Atlantic where this moray resides.

Minimum tank size is 100 gallons (378 liters), due to the high level of waste production.  Although older literature states 30 gallons as the minimum, it is commonly accepted that tanks should be much larger.  A good rule of thumb may be 50 gallons per foot (12″) of eel.  They will use PVC that is 3” around and 2 feet long.  A very tight fitting lid that is heavily weighted, with no holes large enough for escape is imperative.  The shallower the tank, the more leverage they have with their muscular body to knock off a seemingly heavily weighted lid!  Deeper tanks would therefore be recommended, possibly one that is deeper than the length of the eel for it’s protection.  With a solid, tightly fitted lid,  it is necessary to have an external source of oxygen, such as an air pump.  A sealed saltwater tank needs the air above the surface to be oxygenated and this external source of oxygen, carbon dioxide will build up in the space between the surface of the water and the lid, causing depressed pH.  A quick pH drop will kill your eel.  Use open tubing so the bubbles are large if desired.  Form large caves and crevices that can hide their entire body.  Strong water movement helps with filtration.   Any light is acceptable as long as the inside of their hiding spot is completely dark.  They will swim near the bottom of the tank.  

For more Information on keeping this fish see:
Guide to a Happy, Healthy Marine Aquarium

Habitat: Distribution / Background

The Chain Moray Eel was first described by Bloch in 1795.  Some of the common names these eels are known for, which typically describes the highly variable color and pattern on their body are Chain Moray, Chain Moray Eel, and Little Banded Eel.  The common names, Atlantic Chain Moray Eel and Chainlink Moray Eel are retailer’s names, and are not accepted as scientific.

In the moray eel family, there are 15 genus’ and about 200 species!   Only about 12 of these species are suitable for home aquaria.

Distribution – Habitat:
The Chain Moray is found in the Western Atlantic from Bermuda, Florida (USA), Bahamas to the Antilles, Brazil, Cape Verde, Ascension Island, and the southern Atlantic Islands. They are found close to the substrate as solitary creatures on rocky shore areas and reefs, from depths of 5 to 39 feet (1.5 to 12 m).  They can be out of water for up to 30 minutes as they wiggle from tide pool to tide pool in search of food.  They will also poke into crevices and holes, will sneak up on pray, chase pray or ambush prey from underneath the rocks or crevices.  Main foods are small fish and crustaceans such as Sally Lightfoot Crabs (Grapsus grapsus) and other crustaceans.  Crabs can be hunted visually, yet due to the eels poor vision, a nearby fish darting by can cause the moray to miss it’s target.  At that point, the chase begins after the crab for up to 16 feet (5 m).  At times, the passing fish is eaten instead!

These eels are found alone in the wild.   Fish that are known to eat the Chain Moray in these Atlantic Waters are the Mutton Hamlet (Alphestes afer), the Red Grouper (Epinephelus morio), the Nassau Grouper, (E. striatus), and the Schoolmaster Snapper (Lutjanus apodus) 

They have not been evaluated by the IUCN Red List of Endangered species.  

• Scientific Name: Echidna catenata
• Social Grouping: Varies – Although found solitary in the wild, two can be added at the same time with plenty of space and hiding places.
• IUCN Red List: NE – Not Evaluated or not listed

Description

Chain Moray Eels are white to yellow with mottling that is black, brown or gray.  The coloring runs into their dorsal and pelvic fins.  Juveniles have less markings than adults and each individual eel has a unique pattern.  The Chain Moray have one continuous dorsal fin and a lower continuous pelvic fin.  They lack scales so they produce a mucus layer, and they lack bone on their gill plates so they can squeeze into crevices in the reef as they search for food.  The Chain Moray have blunt, molar shaped teeth used for masticating crustaceans.  They have an excellent sense of smell, with 2 tube like appendages on their nose and two holes at the top of their head.   There are taste buds on the tip of their nose and mouth.  This, along with a keen sense of smell makes up for their poor vision due to their small eyes.  In the wild, they grow up to 28” (71 cm), but some have reported tank raised morays reaching 34.”  These fish can live up to several decades, so there is a huge commitment on the part of the aquarist. 

• Size of fish – inches: 28.0 inches (71.12 cm) – 28” (71 cm) Some have reported tank raised morays exceeding stated lengths by 2 to 4.”
• Lifespan: 20 years – Moray eels can live 20 years or more.

Fish Keeping Difficulty

Although there is an author who is renowned for his excellent research, 30 gallons has been widely agreed as being too small for this eventually 28” long (71 cm) eel.  The water quality would be poor at best, and although the eel can live in water that is not as high quality as other fish, it should not be subject to those conditions, and may cause it to stop eating.  Smaller tanks also provide more leverage for the eel to shove off a seemingly heavily weighed lid.  Looking at the suggested tank sizes, it seems that the eel needs about 50 gallons or more per 1 foot (12” of eel).  Cleaning the tank every week is suggested, due to the copious amounts of waste morays produce, unless tank is hundreds of gallons.  A very strong skimmer and strong water movement will help in this area.  If there are no corals, a strong and frequently cleaned canister filter is suggested.  No fiberglass decorations are to be used, since they will cause the eel to develop sores on their skin.  Feed a wide variety of crustacean flesh as well as live crabs from saltwater sources.    

• Aquarium Hardiness: Very Hardy – Long term care is less hardy, with the eel needing live saltwater sourced crabs along with regular feedings.
• Aquarist Experience Level: Intermediate – This is due to long term care and the need for a much larger tank, which is not common for beginners.

Foods and Feeding

The Chain Moray Eel is a carnivore that should not be fed freshwater fish, flake or pellets.  To elicit a feeding response, try live shrimp and fiddler crabs.  You can easily train your eel during this time with chunks of crustacean flesh skewered on a feeding stick.  Gently bump the food on the nose and mouth of the eel once or twice.  If the eel does not take it, do not force feed.  Try again the next day since you do not want the eel to associate this feeding method as aggressive.  The foods that you need are easily found at your local grocery store!  These are fresh gulf shrimp with shells, whole blue crab, octopus and squid that are fully thawed.  Keep their food varied and feed every 3 or 4 days to satiation.  To sustain this eel long term, feed live saltwater sourced crabs along with the above mentioned store items.  When the moray starts to look for food, that is when you feed him/her.  Do not over feed, or your eel can develop fatty deposits on it’s liver, compromising it’s health.

• Diet Type: Carnivore – Provide varied crustacean diet along with live foods.
• Flake Food: No – They need fresh and varied crustacean flesh.
• Tablet / Pellet: No – They need fresh and varied crustacean flesh.
• Live foods (fishes, shrimps, worms): Some of Diet – Fiddler crabs and glass shrimp can be used to elicit a feeding response. Switch to chunks of varied crustacean flesh on a feeder stick within 2 to 3 weeks.
• Meaty Food: All of Diet
• Feeding Frequency: Daily – Feed every 3 to 4 days until satiated.

Aquarium Care

Maintenance:
Reef tanks

• Medium sized up to 90 gallons, perform 15 to 20% weekly. 
• Large Tanks 100 gallons and over, once water is aged and stable can be changed 15% to 20% weekly, depending on bioload.

Fish only tanks:

• Medium sized up to 90 gallons, perform 10% to 20% weekly. 
• Large Tanks 100 gallons and over, 10 to 20% weekly.

For more information on maintaining a saltwater aquarium see: Saltwater Aquarium Basics: Maintenance. A reef tank will require specialized filtration and lighting equipment. 

• Water Changes: Weekly – Recommended 10% to 20% the day after feeding.

Aquarium Setup

Rock work should be heavy and securely sitting on the glass bottom of the tank.  Non-toxic zip ties can be used to hold rock work together, so the clumsy movements of the Chain Moray Eel does not topple it and cause themselves injury.  Form at least one or two caves or deep crevices that allow the eel to completely hide his body.  The area inside these hideouts should be completely dark.  A very tight fitting lid, secured with heavy weights or very strong clips are needed since these eels are very strong and can push lids open, so deeper tanks are better.  Make sure any holes on the lid are small enough to prevent the eel from escaping.  Sand is the best substrate since they like to burrow.  Even PVC that is 3” around and 2 feet long will be used, but do not use decorations made out of fiberglass. Juveniles can be housed in smaller tanks, with an estimate of 50 gallons per 12” or 1 foot.  Chain Morays can be housed together if added at the same time in a tank that is twice as big for one, and several hideouts are provided.  

• Minimum Tank Size: 100 gal (379 L) – 100 gallons (378 liters) Older literature says 30 gallons, but figure on 50 gallons per foot of eel.

• Suitable for Nano Tank: No
• Live Rock Requirement: Typical Plus Hiding Places – Caves and deep crevices large enough to hide their entire body.
• Substrate Type: Sand – Moray eels love to dig.
• Lighting Needs: Any – Ensure their hide out is completely dark inside.
• Temperature: 72.0 to 80.0° F (22.2 to 26.7&deg C) – 72˚ F (22˚ C) Water below this will result in the eel refusing to eat. 80˚ F (27˚ C)
• Breeding Temperature: – Unknown
• Specific gravity: 1.022-1.025 SG
• Range ph: 8.0-8.4 – Low pH from too much organic waste will cause the eel to change in behavior and coloring.
• Brackish: No
• Water Movement: Strong – To aid in filtration.
• Water Region: Bottom

Social Behaviors

These eels can be housed together or with other moray eels if they are added at the same time.  The tank should be very large and there should be several hideouts to prevent aggression.  If an eel were to bite another, the wound will have a protective covering within a day and a half, and by 2 or 3 weeks it will be completely healed and without a scar!  

Chain Moray Eels are crustacean eaters, who generally leave fish alone.  The only time they can be a danger to fish is if chunks of food are just dropped into the tank, creating a feeding frenzy where they will strike at anything that they bump into, in the direction of the scent of food.  To prevent this, train them with a feeding stick that has food stuck on the end and gently bump their nose a few times while they are in their cave or hideout with their head sticking out.   Trained this way, morays are likely to stay put and when fed 3 to 4 times a week, will stay satisfied.  It has been noted that cleaner wrasses tend to be accidentally eaten in captivity. Again,  bumping into the nose of a hungry eel…. not a good idea if your a fish or a hand connected to a body.  It is accidental, but it still hurts, or kills!

Corals are left alone, and the movements of the eel behind the rocks actually helps stir dead zones.  The only time a coral is at risk is if the eel knocks it over or dislodges the rock the coral is affixed to.  This can easily be remedied by securing the rock and the coral.  SPS corals need much cleaner water than soft corals and some LPS.  Due to this fact, a Chain Moray Eel may not be the best choice in such a reef set up unless the reef is hundreds of gallons and can handle the waste these fish produce.

The only inverts these eels are a threat to are crabs and an occasionally shrimp, though cleaner shrimp are not typically eaten. 
 

• Venomous: No
• Temperament: Semi-aggressive – Only due to accidental biting of fish.
• Compatible with:
  • Same species – conspecifics: Yes – Add at the same time in very large tank.
  • Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Monitor – Only a threat if eel is not stick trained, and fish is mistaken as food.
  • Semi-Aggressive (anthias, clownfish, dwarf angels): Monitor – Only a threat if eel is not stick trained, and fish is mistaken as food.
  • Monitor – Only a threat if eel is not stick trained, and fish is mistaken as food, however large aggressive damsels may pick on the eel.
  • Large Semi-Aggressive (tangs, large angels, large wrasses): Monitor – Only a threat if eel is not stick trained, and fish is mistaken as food.
  • Large Aggressive, Predatory (lionfish, groupers, soapfish): Monitor – Only a threat if eel is not stick trained, and fish is mistaken as food. Several groupers will eat this eel.
  • Threat – These move too slow and will accidentally be eaten.
  • Anemones: Safe – Only if water quality is kept up and proper lighting is provided.
  • Mushroom Anemones – Corallimorphs: Safe – Only if water quality is kept up and proper lighting is provided.
  • LPS corals: Safe – Only if water quality is kept up and proper lighting is provided.
  • SPS corals: Safe – Only if water quality is kept up and proper lighting is provided.
  • Gorgonians, Sea Fans: Safe – Only if water quality is kept up and proper lighting is provided.
  • Leather Corals: Safe – Only if water quality is kept up and proper lighting is provided.
  • Soft Corals (xenias, tree corals): Safe – Only if water quality is kept up and proper lighting is provided.
  • Star Polyps, Organ Pipe Coral: Safe – Only if water quality is kept up and proper lighting is provided.
  • Zoanthids – Button Polyps, Sea Mats: Safe – Only if water quality is kept up and proper lighting is provided.
  • Sponges, Tunicates: Safe – Only if water quality is kept up.
  • Shrimps, Crabs, Snails: Monitor – Cleaner Shrimp are safe, however crabs will be eaten and snails may be eaten.
  • Starfish: Safe
  • Feather Dusters, Bristle Worms, Flatworms: Safe
  • Clams, Scallops, Oysters: Safe – Only if water quality is kept up and proper lighting is provided.
  • Copepods, Amphipods, Mini Brittle Stars: Safe

Sex: Sexual differences

Unknown

Breeding / Reproduction

Little is known, although most morays are known to spawn in the spring and summer.  Some spawn several times during these seasons and some will spawn only once a year.  A male and female pair of morays have been observed in the wild, wrapped around each other with their mouths open.  They were pressing their abdomens together, then as they released their gametes into the water, they quickly pulled apart.  The eggs are 1.8 to 4 mm and the larvae are called leptocephalus.  They have small heads, large eyes and long, flattened, ribbon-like, clear bodies.
 

Not accomplished in captivity. See Breeding Marine Fish page for a description of how they reproduce in the wild.

• Ease of Breeding: Unknown

Fish Diseases

Occasionally, your Chain Moray eel will refuse to eat.  This can be caused by overfeeding, poor water conditions or a drop in water temperature.  Sometimes there seems to be no reason for an eel to go 2 weeks without eating, then it suddenly eats again.  If poor water conditions are suspected, it may take several weeks for them to start feeding again.  In the meantime, do several larger partial water changes to remedy the problem.  Morays have been known to go 2 months without eating, with not weight loss or health issues. 

Rarely, eels are inflicted by parasites.  Their behavior of flicking their dorsal fin up and down, head-shaking or rubbing it’s head against rocks or other hard, rough surfaces is a dead giveaway.  Occasionally, eels contract nematode worms, which are squiggly, raised bumps under their skin.  Do not use medications containing copper compounds and oganophosphates, namely, masoten, dylox, Dipterex, Neguvon, and Malathion.  Malathion, for example is found in some medications to treat nematodes on fish.   What to do?  Massive water changes or place them in a treatment tank with PVC so they can hide, with an extremely heavy lid, and treat with erythromycin (Maracyn) for bacterial infections. 

For information about saltwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.

Availability

Chain Eels are seasonal, and are average priced for saltwater fish.

References

BOOKS:
REEF FISHES VOLUME 1
by Scott W. Michael
Published by Microcosm Ltd.
Copyright ©1998 by Scott W. Michael
Illustrations copyright ©1998 by Joshua Highter

WEBSITES:
WETWEBMEDIA.COM
FISHBASE.ORG
IUCN RED LIST

REEFKEEPING
An online magazine for the marine aquarist

Reef Central
Fish Tales By Frank Marini, PhD.
A Serpent For Your Reef Tank – A Look at Fish-Safe Eels

FishChannel.com
Moray Eels
By Scott W. Michael
Copyright ©2013 I-5 Publishing, LLC. All rights reserved.

 Chain Moray Eel Echidna Catenata (Image Credit: Kris Mikael Krister, Wikimedia Commons CC BY-SA 3.0 Unported)