Microlepidogaster discus is a small, dorsoventrally flattened loricariid from southeastern Brazilian river systems whose disc-shaped body is reflected in its species name. The genus Microlepidogaster is closely related to Hisonotus and the other otothyrine loricariids, and its members are characterised by fine scale patterning and a slender, flattened body profile adapted for life on smooth hard substrates in clear-water streams.
In its natural habitat of southeastern coastal rivers in Brazil's Atlantic Forest zone, M. discus inhabits shallow, well-oxygenated, moderately flowing streams with rocky and gravelly substrate. It grazes periphyton and soft algae from smooth rock and plant surfaces, and its flat body allows it to hug tight to surfaces even in moderate current. The streams it inhabits are typically clear, moderately cool, and well-lit, supporting productive algal growth.
For aquarists, Microlepidogaster discus is a delicate and rewarding species for the carefully maintained planted aquarium. Its small size and particular sensitivity to water quality place it in the same care category as Nannoptopoma spectabile — suitable for expert nano-fish keepers who can maintain the stable, pristine conditions it requires. It is rarely available in the trade and commands considerable collector interest.
