Microglanis carlae, new species, is described from the río Paraguay basin and distinguished from its congeners by the following combination of characters: paired and anal fins mottled or with thin faint bands, trunk with dark-brown saddles, anterior margin of pectoral spine with serrations retrorse proximally and antrorse distally, tip of pectoral spine as a distinct bony point, continuous portion of lateral line reaching vertical through last dorsal-fin ray, caudal peduncle with irregularly shaped, faint to dark blotch, maxillary barbel surpassing vertical through dorsal-spine origin, and dark bar on posterior flank continuous from base of adipose fin to that of anal fin. The new species is included in the Microglanis parahybae species complex on the basis of color pattern.
Species delimitation in the Stenocereus griseus (Cactaceae) species complex reveals a new species, S. huastecorum