Corumbataia cuestae

Corumbataia cuestae is a diminutive otothyrine loricariid from the upper Paraná River drainage, a major South American river system flowing through central Brazil, Paraguay, and Argentina. The genus Corumbataia is named for the Corumbataí River in São Paulo state, one of its type localities. C. cuestae is among the smallest loricariids described in this catalogue, reaching barely 3.5 cm, and has a highly cryptic, mottled brown-and-grey body pattern that provides excellent camouflage against leaf litter and fine gravel.

In nature, C. cuestae inhabits clear-water streams and river tributaries of the upper Paraná system, where it conceals itself among leaf litter and fine substrate, emerging to graze periphyton and biofilm from sand grains, small pebbles, and submerged wood. It is likely a low-light, shade-preferring species given the habitat description. Its small size means it is almost exclusively a fine biofilm and soft algae consumer rather than a processor of coarser algal growth.

For aquarists, Corumbataia cuestae is a nano specialist's species — very small, cryptic, and delicate, requiring excellent water quality, an intimate aquarium with well-established biofilm, and very peaceful tank mates. It will be invisible to the casual observer but deeply rewarding for the collector who takes the time to create appropriate conditions. Its upper Paraná origin suggests moderate water conditions are suitable rather than the extreme softness required for some Amazonian species.

Water: Soft to moderately hard at pH 6.5–7.5 and 20–26°C; very clean, stable water; sensitive to organic waste accumulation. Tank: 40 litres minimum with leaf litter, fine substrate, driftwood, and dense planting for cover and foraging. Feeding: Biofilm on fine substrate and leaf litter; fine algae wafers crumbled near substrate level. Breeding: Not documented in captivity. Compatibility: Only with the smallest, most gentle nano species and invertebrates; avoid any fish that might outcompete it.