Fire Eel

About

The fire eel (Mastacembelus erythrotaenia) is one of the largest and most recognizable members of the spiny eel family, a group named for the row of small defensive spines running along the back. Harmless to humans but distinctive to the group. Native to the slow-moving rivers and seasonally flooded plains of Thailand, Cambodia, and Indonesia, this species spends much of its time nosing through soft substrate in search of worms, insect larvae, and anything else it can swallow. In the aquarium it maintains that same methodical, almost serpentine character, and while it is broadly peaceful toward tankmates its own size, anything small enough to fit in its mouth is fair game. Especially after the lights go out, since this is a genuinely nocturnal animal. Keeping two fire eels together can lead to friction, though some keepers have had success with groups of five or more where aggression gets spread around. Breeding in captivity has happened, but only by accident rather than by design. Wild populations appear to have declined in recent years, which is worth bearing in mind. Given its potential length and need for a large, well-filtered tank with soft substrate and hiding spots, this species suits an intermediate keeper who has planned ahead.