Breeding Auchenipterichthys punctatus

Breeding notes for Auchenipterichthys punctatus, the polka dot catfish: an Amazonian woodcat whose genus reproduces by internal fertilization with female sperm storage.

Overview

Auchenipterichthys punctatus, the polka dot catfish, is a driftwood catfish (woodcat) of the family Auchenipteridae from the Amazon basin. Like its congeners it is a peaceful, primarily nocturnal bottom-dweller. Species-specific spawning records for A. punctatus are scarce, so the reproductive information below is drawn from the well-documented pattern shared across the genus Auchenipterichthys, of which this species is a recognised member.

Sexing

Across the genus, mature males develop a modified anal fin used for internal insemination, with the urogenital opening at the end of a tube bound to the anterior margin of the anal fin. Females have an enlarged urogenital opening. In related species, serrae on the end of the dorsal fin spine are proportionally longer in breeding males than in juveniles and females.

Spawning Behavior & Trigger

The genus practises internal fertilization: the male uses his modified anal fin as a means of internal insemination, after which the female can later lay the eggs in isolation. Females have been observed to store sperm and produce fertile eggs in the absence of males, with eggs deposited directly onto the substrate.

Common Challenges

Because verified spawning accounts for A. punctatus itself are scarce, breeding it relies on extrapolating the genus pattern. The nocturnal, secretive habits of these woodcats also make spawning behaviour difficult to observe directly.