Fire Eels

Fire Eels

The Fire eel have red markings and is a color full addition the aquarium, as long as the tank is large enough to house this big eel. If you keep your Fire eel in sub-optimal conditions the colors can fade. Getting a Fire eel for a small aquarium is therefore not a good idea.

The scientific name for this fish is Mastacembelus erythrotaenia and wild specimens are found in floods and streams in India, Borneo, Malaysia, Sumatra, Sri Lanka, Thailand and Burma (Myanmar). The Fire eel has an elongated body that can reach a length of 100 centimeters (40 inches) in the wild. The snout is pointed.

When kept in captivity, the Fire eel seldom grows longer than 50 centimeters (20 inches), but it can grow much larger in captivity if the aquarist provides it with plenty of space and good conditions. House your Fire eel in an aquarium that is large enough and feed it live food, such as feeder fish, mosquito larvae, cyclops, bloodworms and brine shrimp. Many Fire eels will accept flakes and catfish sinkers in captivity, but live food should always be included in their diet. To begin with, a Fire eel is usually very shy and prefers to come out only during the night. If you provide your Fire eel with an aquarium setup that makes it feel safe, it can however become quite an affectionate fish and learn to eat food right out your hand.

As long as your Fire eel is smaller than 15 centimeters (6 inches), you can house it in a 91 centimeter (36 inches) long aquarium that have a capacity of 132 liters (35 gallons). As your Fire eel grows, you must of course move it to larger and larger aquariums. Keep in mind that this fish can grow very fast, and the 15 centimeter Fire eel that you find in the pet shop can reach a size of 1 meter within a year if you provide it with optimal conditions.

The elongated body of the Fire eel has a dark brown color, except for the belly which is light brown to light gray. The body is usually decorated with vividly red lateral stripes and spots, and these patterns can be used to distinguish one individual from another. The dorsal, pectoral and anal fin will also very often display a red edging. The decorative patterns will change as the fish ages, and juvenile fish will typically display yellow decorations that gradually become more and more red as the fish reaches maturity. The intensity of the color will often be affected by the general condition of the fish. A few of the most common health problems among Fire eels are parasite attacks, injuries and shock.

The Fire eel is a bottom living species that likes the soft Southeast Asian riverbeds. The bottom of your aquarium should therefore be covered in fine gravel without any sharp edges, since sharp edges can hurt this burrowing fish. The Fire eel likes to bury itself in the substrate and show nothing but its head. It will however spend a lot of time out of the sand compared to most other Mastacembelus species.

Fire eel picture
Fire eel, Mastacembelus erythrotaenia. Copyright

Mimic the densely grown Asian streams by keeping the aquarium densely planted, and preferably add some floating plants to the set up. Floating plants will make the light less sharp for this nocturnal species. Your Fire eel will feel more secure in the aquarium if you give it pipes of suitable size to hide in. Creating sheltered areas by using rocks, wood and roots is also recommended. It is important that you cover the aquarium, since the Fire eel can jump very high. It is also a skilled escape artist and the aquarium must be properly sealed.

Since the Fire eel inhabits Southeast Asian rivers and streams, it will prefer a warm temperature between 24-27° C (75-81° F), a pH of 7 and a dH of 10. It will however tolerate a pH in the 6-7.5 range and a dH between 6 and 20. Adding some salt to the water is a very good idea.

The Fire eel is quite peaceful, particularly when it comes to young specimens. Keeping it will small fish is however a bad idea since these will be considered prey. You can for instance house your Fire eel in a community aquarium with medium sized or large cichlids. Avoid keeping more than one Fire eel in the same aquarium, unless you plan to breed them. Two Fire eels will seldom get along well with each other. A Fire eels that has been added to the aquarium when it was very small will sometimes tolerate small fish in the aquarium, and refrain from eating them even when it grows much larger. If you add new small fish to the set up it can however happily devour the newcomers.

Breeding Fire Eels

Breeding Fire eels in captivity is very hard, but not impossible. Distinguish the sexes can be difficult, but a mature female is plumper than the male. When spawnings have occurred in captivity, the parents have been longer than 50 centimeters (20 inches). The Fire eel is a plant spawning fish that should be kept in a large and well planted aquarium. Keep the pH and dH at optimal levels and let the water temperature become a little higher than normally, from 27 to 29° C (81 to 84° F). The eggs are translucent and the female Fire eel will place roughly 800 to 1200 eggs in floating plants. The eggs are around 12 millimeters (1/20 inch) in diameter. Newly hatched Fire eels must be feed very small live food. Over feeding the fry is a common reason behind extensive Fire ell fry death. When kept on a suitable diet, the fry will grow very fast.

picture of two fire eels in a pipe
Two fire eels hiding in a pipe. Copyright

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