Hoplo Catfish
October’s fish of the month is an odd, often overlooked species – the Hoplo Catfish.
Discovered in the 1840’s, this fish may be found labelled under Callichthys or
Hoplosternum, though it is currently accepted as a member of Megalechis. There are
currently two recognized species of Hoplo cat, M. thoracata, the Marbled Hoplo, and M.
picta, the Spotted Hoplo. Both species are remarkably widespread, found in essentially all
rivers east of the Andes mountains.
A relative of the highly popular Corydoras catfish, Hoplo cats have remarkably similar
physical features and social requirements. They have thick armored plates in place of
scales, sensory barbels about the mouth and prefer to live in schools of at least five or
more. Hoplo catfish can be differentiated from Corydoras in both water requirements and
size. Where Cory catfish typically grow to 3 inches at most, Hoplo catfish easily reach 6+
inches. Hoplo catfish are also far less picky about water requirements, and will acclimate to a pH of 6.0 to 8.0, up to 25dgH, and can survive in water temperatures of 64 to 82
Fahrenheit. The most important requirement when keeping these fish is ensuring they
have many hiding places. Heavy planting, heavy Malaysian Driftwood, caves, and soft
sand, such as Estes Stoney River sand, are essential in your success with this fish. As this species is an air breathing catfish, make sure to leave a gap between the surface of the
water and the lid of the tank.
Finally, Hoplo catfish are not picky eaters. Sinking foods such as Hikari’s frozen bloodworms and Tetra’s tropical tablets will be rapidly consumed. As adults, Hoplos should be offerd Mysis Shrimp and Chopped Krill in addition to sinking pellets. Avoid housing
these fish with any small or ‘nano’ fishes, as they will be eaten once your Hoplo cats reach an appropriate size, and typically late at night. Good tankmates include Rainbowfish,
larger Tetras, Barbs, and mild mannered South American Cichlids.
A quirky and active species, Hoplo catfish are a fantastic addition to your large fish community.