TankBud

Marbled helogenes

Helogenes marmoratus

Also known as Smoothhead catfish, Midnight cat

FreshwaterFish

Marbled helogenes (Helogenes marmoratus)

Care at a glance

Temperature
73–82°F
23–28°C
pH
4.5–6.8
Adult size
3.1 in
8 cm
Minimum tank
14 gal
54 L
Temperament
Peaceful
Social behavior
Social
Swim level
Middle
Difficulty
Medium
Breeding
No record
Rarity
Rare
Family
Cetopsidae
Origin
Blackwater creeks of the Guianas and Amazon

Overview

The marbled helogenes is a shy, night-active catfish for a dim, leafy blackwater tank. It suits a keeper with a little experience.

Did you know

The marbled helogenes often lies on its side among the leaf litter, colored like a dead leaf. It drifts slowly through the water at an angle rather than swimming upright. The disguise is so complete that keepers lose track of it in their own tanks.

Caring for the marbled helogenes

A group of marbled helogenes needs a dimly lit tank of at least 14 gal (54 L), heavy with cover. Give them a soft, dark setup with tannin-stained water from botanicals and wood, and plenty of leaf litter to hide in. By day they hide in the litter and roots, drifting out to feed once the lights go down.

It wants warm, very soft, acidic water at 73 to 82°F (23 to 28°C) and a low pH of 4.5 to 6.8. Feed at lights-out with fine sinking and frozen foods such as bloodworm and daphnia, so enough reaches them.

Marbled helogenes do best in a small group of their own kind. Keep several together and they will feel secure enough to show themselves. They are gentle and easily outcompeted, so choose small, peaceful blackwater tank mates. The species has not been bred in aquaria, so its spawning habits are undocumented.

Good to know

Helogenes marmoratus is the hobby's cetopsid, or whale catfish. It sits at the gentle end of a family that also includes flesh-eating relatives. It is a soft-bodied, leaf-patterned fish. In the wild it feeds heavily on ants and other terrestrial insects that fall to the water.

In the wild

The marbled helogenes lives in shaded blackwater and clearwater forest streams of the Guianas and Amazon, among drifting leaf litter and tangled roots.

Weekly picks

Tank mates

The marbled helogenes is a peaceful, social species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a marbled helogenes need?

A marbled helogenes needs at least 14 gal (54 L). It spends most of its time in the middle.

What temperature and pH does a marbled helogenes need?

A marbled helogenes is comfortable at 73–82°F (23–28°C) with a pH of 4.5–6.8.

What does a marbled helogenes eat?

A marbled helogenes eats fine sinking and frozen foods such as bloodworm and daphnia. It is easily outcompeted, so feed it at lights-out to make sure enough reaches it.

How big does a marbled helogenes get?

An adult marbled helogenes reaches about 3.1 in (8 cm).

Related species