Peacock eel

The peacock eel is a slender, elongated spiny eel native to the slow-moving streams, floodplains, and marshes of mainland Southeast Asia, including Thailand, Cambodia, Vietnam, and Myanmar. Despite its eel-like appearance reaching up to 30 cm in captivity, it is not a true eel but a member of the family Mastacembelidae, distinguished by the series of small dorsal spines preceding its soft-rayed dorsal fin. Its common name comes from the attractive peacock-like pattern of dark spots and irregular markings along a brownish-tan body, with a faint lateral stripe running from the gill cover to the tail. Like all spiny eels, it has a pointed snout used for rooting through soft substrate in search of food.

Peacock eels are primarily nocturnal and spend much of the day buried in soft sand with only the snout and eyes visible — a normal and entertaining behaviour. The aquarium must have a soft sand substrate, as gravel will abrade their delicate skin and lead to infections. A 150-litre tank is the recommended minimum for a single adult, with the footprint being far more important than height since these are bottom-dwellers. The setup should include plenty of hiding places: driftwood caves, PVC pipes, smooth rocks, and dense plant thickets, with dim lighting and floating plants to diffuse the light. Water conditions should be stable with a temperature of 23–28°C and a pH of 6.0–7.5. A secure, tight-fitting lid is absolutely mandatory — these eels are notorious escape artists that can squeeze through remarkably small gaps.

Peacock eels are carnivorous predators that prefer live and frozen foods such as bloodworms, brine shrimp, blackworms, chopped earthworms, and Mysis shrimp. Some individuals can be weaned onto sinking carnivore pellets, but most require live food when first introduced. They are peaceful towards fish too large to be eaten, making them suitable companions for medium-sized community fish like larger rasboras, rainbowfish, large gouramis, and peaceful cichlids. However, anything that fits in their mouth — small tetras, shrimp, or fry — will be consumed. They are prone to ich and sensitive to medications, so quarantine is essential for new arrivals. Aquarium lifespan estimates are around 5 years with suitable care.