Megalodoras uranoscopus (Ripsaw Catfish) Breeding Guide

Megalodoras uranoscopus is a giant migratory thorny catfish that has never been bred in captivity; this guide explains its biology and sexing.

Overview

Megalodoras uranoscopus is a large thorny catfish of the family Doradidae, also known as the ripsaw or giant raphael catfish. According to Wikipedia it is native to the Amazon basin in Bolivia, Brazil, Colombia, Ecuador and Peru, growing to about 60 cm SL and up to 4.6 kg. Seriously Fish records a maximum of roughly 600 to 700 mm and notes it is suitable only for public aquaria plus an extreme minority of private aquarists. In nature it eats pulmonate snails and fallen fruits such as those of Licania longipetala and Astrocaryum jauari.

Sexing

According to Seriously Fish, adult females appear larger and heavier-bodied than males, and the genital papillae differ in structure between the sexes. These are the only reliable distinctions reported, and they are most apparent in fully grown adults.

Why home breeding is not feasible

The species undergoes extensive seasonal migrations that appear to relate directly to its reproductive cycle, and these cannot be reproduced in a tank. Combined with an adult size of more than half a metre and a minimum recommended tank footprint of about 240 by 120 cm, the migratory spawning behaviour places this fish well beyond home-aquarium reproduction. It is best regarded as a display species rather than a breeding project.