Breeding Auchenipterichthys coracoideus

Breeding guide for Auchenipterichthys coracoideus, the midnight catfish: an Amazonian woodcat with internal fertilization that has been bred in aquaria.

Overview

Auchenipterichthys coracoideus, the midnight or Zamora catfish, is a driftwood catfish (woodcat) of the family Auchenipteridae, reaching about 90-110 mm. Seriously Fish records it from the upper and central Peruvian and Brazilian Amazon basin, plus the Essequibo drainage. It is a peaceful, shy, nocturnal fish that may consume very small fishes at night, kept at 22-25 degrees Celsius and pH 6.0-7.2. Members of this genus are unusual in that they practise internal fertilization.

Sexing

Sexual dimorphism is distinct. Mature males develop a hook-like, modified anal fin used for copulation, functioning in a manner similar to the gonopodium of livebearers, and nuptial males show greatly elongated dorsal spines. According to the Wikipedia genus account, the male's urogenital opening sits at the end of a tube bound to the anterior margin of the anal fin, while females have an enlarged urogenital opening.

Spawning Behavior & Trigger

Fertilization is internal: the male uses his modified anal fin to inseminate the female during a spawning embrace. Remarkably, the female can store sperm for later use, and females have been observed laying fertile eggs in the absence of males. The eggs are then laid directly onto the substrate, with the female depositing them in isolation.

Egg & Fry Care

Seriously Fish reports the species has been successfully bred in aquaria in Germany. No parental care has been observed, so the eggs and resulting fry are not guarded by the adults.