Catfish · Driftwood cats

Auchenipterus britskii

Ferraris & Vari, 1999

IUCNLEAST CONCERN
CARESNOT LISTED
Scientific size6 in15.7 cm standard length
Temperature75–82 °F24–28 °C
Depthnot recorded
DietNocturnal benthopelagic micro-predator/omnivore — aquatic invertebrates, small prey and detritus foraged mainly after dark; in the aquarium takes sinking pellets and frozen/prepared foods, best offered after lights-out
BreedingInternal fertilisation via the modified male anal fin (intromittent organ); female stores sperm and spawns later — the driftwood-catfish (Auchenipteridae) pattern. Not documented as bred in home aquaria.
Sexual dimorphismYesAs in other Auchenipteridae, males bear the modified intromittent anal fin used in internal fertilisation; species-specific external dimorphism otherwise undocumented
PhotographsSee photosGoogle Images →

Auchenipterus britskii is a slender driftwood catfish of the middle Amazon basin, described by Ferraris & Vari in 1999 in their revision of the genus. It belongs to Auchenipteridae, the family whose males possess a modified, intromittent anal fin and whose females store sperm and lay fertilised eggs weeks after mating — one of the most unusual reproductive strategies among catfishes. Reaching about 6 in SL, it is a nocturnal, benthopelagic micro-predator of Amazonian floodplain lakes and channels, rarely seen in the hobby and essentially unbred in captivity.

What's in the name

Auchenipterus britskiiaw-ken-ip-TEER-us BRIT-skee-eye

Auchenipterus
  • auchenGreekneck
  • pterusGreekfin/wing — together referencing the fin arrangement near the nape in the type species of the genus
britskii
  • britskiiLatinised patronymhonours Heraldo A. Britski, Brazilian ichthyologist noted for work on Amazonian and Neotropical fish taxonomy

Taxonomy & naming

Auchenipterus britskii was described by Carl J. Ferraris Jr. and Richard P. Vari in 1999 as part of their monographic revision of the genus Auchenipterus, published in a systematic study of the driftwood catfish family Auchenipteridae. The type locality lies in the Lago Janauacá area of the rio Solimões, in the middle Amazon of Brazil. The Catalog of Fishes recognises Auchenipterus britskii as a valid species within the family Auchenipteridae, the driftwood or wood catfishes.

Auchenipteridae has been historically confused with other catfish families, and species within Auchenipterus itself were poorly resolved before Ferraris & Vari's revision sorted the genus's many superficially similar, slender-bodied species. The species epithet britskii honours Heraldo A. Britski, the Brazilian ichthyologist known for his extensive work on Amazonian and Neotropical fish taxonomy.

Morphology

Auchenipterus britskii is a slender, laterally compressed catfish reaching a documented maximum of about 6 in standard length and roughly 62 g in weight. Like other members of its family it lacks scales entirely — the skin is naked, a trait shared with loaches, puffers and other scaleless catfishes that makes it noticeably more sensitive to copper-based medications and many standard fish treatments than scaled species.

As in most Auchenipteridae, the fins carry stiff, serrated spines at the leading edge of the dorsal and pectoral fins that can be locked erect. These spines readily snag in an aquarium net and can jab a careless hand, so the fish is best transferred in a container rather than netted. The body plan is built for an active, midwater-to-bottom lifestyle in open river and floodplain-lake habitat rather than for burrowing or clinging.

Habitat

The species is native to the middle and western Amazon basin in Brazil, with records extending into Colombia in the río Consaya of the Caquetá drainage. It is a benthopelagic fish of the middle Amazon's river channels and associated floodplain (várzea) lakes, including the type locality of Lago Janauacá on the rio Solimões.

As a wide-ranging Amazonian species it lives in warm, tropical freshwater typical of the middle Amazon mainstem and its floodplain lakes. Specific published water-chemistry data for this species is sparse; aquarists keeping it should default to the warm, soft-to-neutral conditions typical of Amazon mainstem and floodplain habitats rather than assuming strongly acidic blackwater, which is more characteristic of Amazon tributary systems than of the mainstem lakes it favours.

Feeding

Auchenipterus britskii is a nocturnal benthopelagic micro-predator, reflected in its trophic level of about 3.4 on FishBase. In the wild it forages mostly after dark over the bottom and through open water for aquatic invertebrates, small prey and detritus, a foraging pattern typical of driftwood catfishes generally.

In the aquarium, driftwood cats of this type take sinking pellets and frozen or prepared foods readily once acclimated, but do best when fed after the lights go out, matching their natural nocturnal activity. Offering food only in daylight risks the fish being out-competed by more visible, diurnal tankmates.

Mating

Auchenipteridae, the family to which Auchenipterus britskii belongs, is exceptional among catfishes for using internal fertilisation. In males the anal fin is modified into an intromittent organ used to transfer sperm directly to the female during mating. The female then stores the sperm in her reproductive tract, sometimes for an extended period, before laying fertilised eggs later — decoupling mating from spawning in a way almost unheard of elsewhere among catfishes.

Species-specific observations of A. britskii's mating behaviour have not been documented in the sources available; the pattern described here is drawn from the broader biology of the driftwood catfish family, of which this species is a typical member.

Breeding

Following the family pattern, spawning in Auchenipterus britskii is expected to occur after the female has stored sperm from an earlier internal mating, with eggs laid later — often in a small cave or sheltered site — rather than scattered freely in open water at the time of mating. Reported clutch sizes for driftwood catfishes in this group are modest (on the order of a hundred eggs), with a short incubation of a few days, and some female-guarded care has been documented in related genera, though this varies across the family.

Auchenipterus britskii is not known to be bred in home aquaria. Like most driftwood catfishes it is a seasonal breeder tied to natural flood-pulse cues in its native floodplain habitat, conditions that are difficult to replicate in captivity, and it is essentially absent from the aquarium trade's breeding programmes.

In the aquarium

This is not a common aquarium fish, and hobbyist care information specific to Auchenipterus britskii is sparse. Any tank should be sized to its real adult length of roughly 6 in SL — a modest size for a catfish, but still enough to need generous swimming room in a species built for open water rather than a cramped setup.

Because it is scaleless, it shares the medication sensitivity common to naked-skinned catfishes: copper-based treatments and many standard medications should be dosed conservatively, often at reduced strength. Its dorsal and pectoral spines can lock and are prone to tangling in a net, so it should be moved in a container. As a nocturnal fish it benefits from driftwood, overhangs or other cover for daytime shelter, with feeding best offered after lights-out. Given how little is documented about this species in captivity, it should be considered a fish for the experienced, research-minded keeper rather than a beginner community option.

Conservation

The IUCN Red List assesses Auchenipterus britskii as Least Concern. It is a wide-ranging middle Amazon species without documented major threats, and FishBase characterises its populations as resilient, with a minimum population doubling time of under fifteen months.

As with many Amazonian floodplain fishes, its long-term status is nonetheless tied to the health of the várzea lake and river-channel habitats it occupies; broader pressures on Amazon floodplain systems — including damming, deforestation and climate-driven changes to the flood pulse — are the general concerns for species in this guild, even where the species itself is not currently classed as threatened.

Sources

  1. FishBase — Auchenipterus britskii
  2. IUCN Red List — Auchenipterus britskii
  3. Ferraris & Vari (1999) — revision of the genus Auchenipterus (Siluriformes: Auchenipteridae)
  4. Driftwood catfish (Auchenipteridae) breeding biology overview
  5. Driftwood catfish (Auchenipteridae) family care overview

Last reviewed 2026-07-01.

How to cite

Aquarist Atlas (2026). Auchenipterus britskii. Aquarist Atlas.https://www.aquaristatlas.com/catfish/auchenipterus-britskii/

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