Peacock Eel Care Guide – Setup, Diet & Breeding Notes

The Peacock Eel, Macrognathus siamensis, is a slender spiny eel with an elongated body, a pointed snout and a series of small dorsal spines preceding the dorsal fin. Its warm brown body is marked with darker irregular bands and blotches, while the rear part of the dorsal fin often displays distinctive eye-like spots that give the species its common name.

Despite their eel-like shape, Peacock Eels are not true marine eels. They belong to the spiny eel family and use their flexible bodies and pointed snouts to investigate the substrate for food. They are generally peaceful, secretive fish that become more visible once settled, especially during the evening and at night.

In the wild, these eels spend much of their time partly buried in mud or soft sediment, with only the head exposed. Their markings provide effective camouflage among leaf litter, roots and submerged vegetation, and their narrow bodies allow them to explore crevices that larger fish cannot reach.

Peacock Eels can become responsive to their keeper and may learn to appear at feeding time, but they are not constantly active display fish. Individuals vary in boldness, with some spending much of the day hidden and others becoming comfortable in open areas after a period of acclimation.

Peacock Eels are native to mainland Southeast Asia, particularly the Mekong, Chao Phraya and nearby river systems of Thailand, Laos, Cambodia and Vietnam. They inhabit slow-moving rivers, floodplain waters, swamps and other soft-bottomed freshwater environments.

A single Peacock Eel should have an aquarium of at least 200 litres, with a floor area around 120 cm long by 45 cm wide or larger; additional eels need substantially more space. Use a deep layer of smooth, fine sand so the fish can bury itself without damaging its snout or skin. Provide caves, rounded wood, rockwork and dense planting to create shaded retreats, while leaving open areas for foraging. The aquarium must have a tightly fitting lid because these eels are powerful escape artists, and all equipment openings should be secured.

Peacock Eels can reach around 30 cm (12 in) in total length, although many aquarium specimens remain closer to 20–25 cm (8–10 in). Females are usually larger and more heavily built than males.

Peacock Eels are carnivorous opportunists that naturally consume worms, insect larvae, small crustaceans and other bottom-dwelling prey. Offer a varied diet of earthworms, bloodworms, blackworms, brine shrimp, mysis shrimp and high-quality sinking carnivore pellets or wafers. Food should reach the bottom, and feeding after the aquarium lights dim often suits their natural crepuscular and nocturnal habits.

Peacock Eels are peaceful with similarly calm, medium-sized freshwater fish that will not compete aggressively for food. Suitable companions can include peaceful rasboras, larger tetras, peaceful barbs, gouramis and non-territorial corydoras or other community catfish. Avoid very small fish and dwarf shrimp, which may be eaten, as well as fin-nipping species, highly aggressive cichlids and boisterous bottom-dwellers that may outcompete or harass them. They can usually be kept singly; multiple eels require ample floor space and plenty of separate hiding places.

Peacock Eels are rarely bred in home aquariums. In nature, spawning is associated with seasonal changes and may be encouraged by very clean, well-oxygenated water, abundant live foods and a gradual increase in water movement or temperature. Pairs scatter adhesive eggs among dense plants or other cover, but the adults may eat the eggs, so a dedicated breeding aquarium and separation of the parents are advisable. The eggs usually hatch within several days, with tiny larvae requiring appropriately sized live foods.

Females are generally longer, deeper-bodied and noticeably plumper than males, particularly when mature or carrying eggs. Males tend to remain slimmer and smaller, but reliable sexing can be difficult outside breeding condition.