Chaetostoma is a genus of armoured suckermouth catfish in the family Loricariidae, the pleco family, found in the fast-flowing foothill and montane rivers that drain the northern Andes — the atlas's 49 species come from Colombia, Peru, Venezuela, Ecuador, Brazil and Panama. Sizes range widely, 2–12 in, and the genus is built for its habitat: a flattened, bony-plated body and a ventral suckermouth strong enough to hold position on rock in fast current, paired with a preference for cooler, highly oxygenated water than the lowland-river plecos most aquarists associate with the family. That upland, cool-water adaptation is the single trait most cited across the genus and is reflected in nearly every species' common name.
In the hobby Chaetostoma are sold almost universally as "rubbernose" or "bulldog" plecos, valued as efficient algae grazers that, unlike many larger Loricariidae, tolerate — and do best in — cooler tank temperatures and strong water movement rather than warm, still tropical setups, making them a popular choice for coldwater and heavily planted or aquascaped tanks. Conservation status across the genus is mixed and, in places, concerning: the atlas tally includes 7 Vulnerable and 8 Endangered species alongside 15 Least Concern and several Data Deficient, a pattern consistent with Andean stream specialists whose entire range can sit within one short, easily disrupted river reach subject to damming, mining runoff or deforestation.