Flagtail Porthole Catfish Care Guide - Setup, Diet & Breeding

The Flagtail Porthole Catfish is a peaceful, bottom-dwelling member of the Callichthyidae family. Its elongated body is covered by two rows of protective bony plates, while a pair of sensitive barbels surrounds the mouth. The body is generally silvery to pale brown, marked with dark horizontal striping that gives the species its distinctive appearance.

Its name comes from the strongly patterned tail, which often shows dark bars or a flag-like contrast against the paler body. The finnage is modest but attractive, and the fish can appear especially striking when it rests over dark substrate or among leaf litter. Like other members of its family, it is capable of gulping air at the surface and using a modified intestine to extract oxygen.

In nature, Flagtail Porthole Catfish spend much of their time searching the bottom for small invertebrates, crustaceans and other edible material. They are generally calm and sociable, often becoming more confident when kept alongside several of their own kind. Although largely nocturnal or crepuscular, they may become active during the day once settled.

This species is less commonly seen in aquariums than many Corydoras, but it has a similar gentle temperament and an appealingly substantial appearance. It is a fascinating choice for aquarists who enjoy observing natural foraging behaviour and the quiet interactions of a group of armored catfish.

Flagtail Porthole Catfish are native to the western Amazon region of South America, with records from Peru and Brazil. They inhabit slow-moving tributaries, flooded forest areas and quiet backwaters with soft, tannin-stained water, leaf litter and submerged wood.

A group of Flagtail Porthole Catfish should have at least 120 litres, with a footprint of roughly 90 by 40 cm for adult fish. Use fine sand or smooth, rounded gravel so their barbels are not damaged while they forage. Provide driftwood, smooth rocks, caves and areas of dense planting, along with shaded spaces and floating vegetation that reflect their quiet, often tannin-rich natural habitat. Efficient filtration, good oxygenation and stable, clean water are important, while a secure lid is advisable because these catfish may surface for air or jump when startled.

Up to around 12 cm (4.7 in) in total length. Females are usually slightly larger and noticeably deeper-bodied than males.

Flagtail Porthole Catfish are omnivorous bottom feeders. Offer a varied diet of sinking catfish pellets and tablets supplemented with frozen or live foods such as bloodworm, brine shrimp, daphnia, mosquito larvae and chopped earthworm. Occasional soft vegetables can provide additional variety, although meaty foods should form an important part of the diet. Feed after the aquarium lights dim if necessary, and ensure food reaches the bottom without relying on leftovers.

Flagtail Porthole Catfish are peaceful community fish and can be kept with similarly calm South American species such as small tetras, pencilfish, peaceful rasboras, dwarf cichlids and other non-aggressive catfish. They also suit gentle livebearers and peaceful labyrinth fish where water conditions overlap. Avoid large, predatory or boisterous species, fin-nippers and aggressive bottom dwellers that may outcompete or harass them. They should not be housed with fish small enough to be swallowed.

Flagtail Porthole Catfish can be bred in a mature, well-conditioned aquarium. A group may spawn after a period of generous feeding with live or frozen foods, followed by slightly cooler, softer water changes. The male builds a floating bubble nest, usually beneath broad leaves or floating plants, and the female deposits eggs into it. After spawning, the male guards the nest, while the adults should be removed or separated from the eggs if losses are a concern. The fry can be raised on infusoria or other very small foods before progressing to newly hatched brine shrimp.

Females are generally broader through the abdomen and more robust overall, particularly when mature and carrying eggs. Males tend to be slimmer, and their pectoral fins may appear somewhat more pointed, but the sexes can be difficult to distinguish outside breeding condition.