Jelly Catfish Care Guide - Aquarium Size, Diet & Breeding

Jelly Catfish are large, heavy-bodied predators with a broad flattened head, a wide mouth and prominent barbels that help them locate prey in dim water. Their soft-looking appearance and subdued brown to grey-brown coloration give them the distinctive common name, although the body is not actually jelly-like in the literal sense.

This is a strongly nocturnal and secretive catfish. It spends much of the day resting on or near the bottom and becomes more active after dark, when it uses its sensitive barbels and sense of smell to investigate the surroundings and ambush prey.

In the wild, Cephalosilurus apurensis is associated with quiet or slow-moving freshwater habitats, where submerged wood, leaf litter and shaded margins provide cover. Its large mouth reflects a predatory lifestyle, and smaller fish may be treated as food rather than companions.

Jelly Catfish are an unusual specialist species rather than a typical community aquarium fish. They are rarely seen in the trade, grow far too large for most aquariums and are best suited to experienced keepers who can accommodate a substantial nocturnal predator.

Jelly Catfish are native to the Río Apure drainage in Venezuela, in northern South America. They inhabit freshwater environments associated with the Orinoco basin.

An adult Jelly Catfish should have at least a 600-litre aquarium, with a footprint of approximately 180 × 60 cm or larger; greater floor space is preferable to extra height. Use a smooth sand or fine-gravel substrate, strong but well-protected filtration and generous oxygenation, while avoiding sharp decorations that could damage the barbels or soft underside. Arrange large pieces of driftwood, broad shelters and shaded retreats, leaving an open area for nocturnal movement. A tightly fitted cover is important because large catfish can be surprisingly powerful and may escape.

Jelly Catfish can reach approximately 40 cm (16 inches) in adult length. Females may become deeper-bodied or heavier than males, but dependable sex-specific maximum sizes have not been firmly established.

Jelly Catfish are carnivores and should receive a varied diet based on meaty sinking foods. Suitable choices include quality carnivore pellets, pieces of earthworm, prawns, mussel, fish and other marine or freshwater foods. Feed after the aquarium lights dim, allowing the fish to locate food naturally, and avoid relying on live feeder fish, which can introduce disease and provide an unbalanced diet.

Jelly Catfish are safest with robust, similarly sized South American fish that occupy different parts of the aquarium, such as large peaceful cichlids, silver dollars, large characins and sturdy plecos. Tankmates must be too large to swallow and calm enough not to harass a resting catfish. Small tetras, livebearers, dwarf cichlids, shrimp and other bite-sized fish are unsuitable because they may be eaten. Avoid highly aggressive cichlids and fin-nipping species, and provide enough space for every fish to establish a refuge.

Jelly Catfish are not commonly bred in home aquariums, and reliable captive-breeding reports are scarce. Their reproduction is believed to involve a mature pair spawning in a sheltered cavity or among submerged roots, with seasonal changes in water level and flow potentially acting as triggers. A very large dedicated aquarium, excellent water quality and substantial adult fish would be required for any serious breeding attempt.

Visible differences between male and female Jelly Catfish are poorly documented. Mature females may be fuller through the abdomen, particularly when carrying eggs, while males are often somewhat slimmer; external identification is not considered reliable outside breeding examination.