Acestridium is a genus of small whiptail catfish in the pleco family, found in river systems of Brazil, Venezuela, and Colombia. Its species carry the strongly compressed, angular body characteristic of "twig" or "whiptail" loricariids, a shape that lets them lie among submerged branches, leaf litter, and plant debris nearly invisible to predators. At 2–2.5 in, Acestridium ranks among the more diminutive whiptail genera in the atlas.
The genus rarely appears in the aquarium trade, and detailed husbandry information for most species is sparse, though the handful of common names attached here, green whiptail, lime whiptail, emerald whiptail catfish, hint at the subtle olive-to-emerald tones that help these fish disappear against submerged wood and plant matter. Where assessed, the genus leans Least Concern, with two of the atlas's seven species classified Data Deficient, again reflecting limited survey coverage of these small, camouflage-dependent stream fish more than any known threat.