Kronichthys is a genus of small armored catfish in family Loricariidae, restricted to the coastal drainages of southeastern Brazil rather than the Amazon basin most plecos come from. The atlas's three species - Kronichthys heylandi (Heyland's armored catfish), K. lacerta, and K. subteres - run 3–6 in. Like its relatives among the neoplecostomine loricariids, Kronichthys carries the family's bony body armor and ventral sucker-mouth, adapted here for clinging to rock and grazing algae in the fast, rocky, well-oxygenated streams of Brazil's Atlantic Forest region.
Kronichthys is not a mainstream pleco - it turns up only occasionally among collectors specializing in Brazilian coastal-stream loricariids rather than the Amazonian L-number trade most aquarists know - but where kept, it wants the same cool, highly oxygenated, current-swept conditions as its native streams, plus driftwood and biofilm to graze. The conservation picture is genuinely good news here: all three atlas species carry a Least Concern rating, a comparatively rare clean sweep for a genus with such a narrow geographic range.