Fire eel

Fire eel
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Synbranchiformes
Family:	Mastacembelidae
Genus:	Mastacembelus
Species:	M. erythrotaenia
Binomial name
Mastacembelus erythrotaenia (Bleeker, 1850)

The fire eel (Mastacembelus erythrotaenia) is a large freshwater fish found in Cambodia, Indonesia, Laos, Malaysia, Thailand, and Vietnam.

Description

The fire eel is an extremely elongated fish (not a true eel) with a distinctive pointed snout and underslung mouth. The body is laterally compressed, particularly the rear third, where it flattens as it joins the caudal fin and forms an extended tail. It is part of a group of fishes called spiny eels that also includes Tire Track and Peacock eels. The group gets the "spiny" part of its common name from the many small dorsal spines that precede the dorsal fin. The fire eel's base coloring is dark brown/grey, while the belly is generally a lighter shade of the same color. The pattern varies by individual. Usually several bright red lateral stripes and spots mark the body. The red markings vary in intensity depending on the age and condition of the individual. Usually the markings are yellow/amber in juvenile fish, changing to a deep red in larger ones. Often the anal, pectoral, and dorsal fins have a red edging.

The fire eel can grow to a very considerable size in the wild with specimens often exceeding 1.2 meters (3.9 ft) in length. However, due to limiting factors in the captive environment they usually reach a maximum of around 55 centimeters (22 in) even in very large aquaria.

Wild populations

Fire eels inhabit river environments with slow to briskly moving water and fine sediment. In the wild they occur across a relatively broad area covering a large part of Southeast Asia including Borneo, India, Malaysia, Myanmar (Burma), Sri Lanka, Sumatra, and Thailand. They are bottom-dwellers that spend large portions of their time buried in the riverbed, often leaving only their snout visible. However, they are voracious predators and when hunting will visit all depths.

Aquarium care

Young fish generally adapt very well to a community aquarium. Small specimens up to around 15 centimeters (5.9 in) can be kept in a tank measuring 60 centimeters (24 in) and75 litres (20 US gal) and are peaceful and undestructive (although their burrowing nature means that they can uproot plants and move bogwood etc).

Larger fish require disproportionately larger tanks and their companions must be of commensurate size to deter the fiery predator. They have a tendency to fight with other fish of the same species.

Fire eels are intelligent. They quickly learn to recognise their keeper and even readily accept food from the hand. Water should be 25–27 °C (77–81 °F) with a pH of 6–7.5. A little salt is welcomed but not essential.

Fire eels often escape uncovered tanks.

Many of the fish may eat only live food,^[1] including tubifex, fish, brine shrimp, mosquitolarvae, bloodworms, mussels etc.

Captive spawning is rare and extremely difficult, even with mature fish over 20 inches (51 cm). Use a large tank with a pH around 7.0, a water hardness from 10–15 dH, and a temperature from 27–29 °C (81–84 °F). They lay 800–1,200 eggs in floating plants (plant spawner). The eggs are clear and measure around 1 millimeter (0.039 in) in size. The young grow quickly, gorging on as much food as is available. Excess food can compromise their health.

References

1. ^ Fire eels in the aquarium

• Jennings, Greg. (2006). 500 Freshwater Aquarium Fish. Firefly Books.
• Froese, Rainer, and Daniel Pauly, eds. (2007). "Mastacembelus erythrotaenia" in FishBase. October 2007 version.
• "The Fire Eel: One Hot Fish". http://www.fishchannel.com/freshwater-aquariums/species-info/eel/fire-eel.aspx. Retrieved 2008-07-20.