pairs of mental barbels; the medial mental barbels are slightly shorter than the lateral mental barbels, which are in turn slightly shorter than the slender maxillary barbels. The anal fin is moderately long, beginning about halfway down the body, with the posterior-most anal fin rays with a slight, membranous attachment to the body. The pelvic fins are usually small. The first pectoral fin ray is spinous and is slightly longer than one-half the length of the first branched ray; however, the spine may have a prolonged distal filament in mature males. Sexual dimorphism is observed in C. ferreirai, C. morenoi, C. orientale, and C. pemon, but not in C. minutum or C. roae. Presumed mature males have the first ray of the dorsal and pectoral fins extended into filaments except in C. ferreirai. Also, the anal fin has a broadly convex margin rather than a straight margin. Cetopsidium species are smaller than Cetopsis species, growing to only SL. References Cetopsidae Fish of South America Fish of Brazil Fish of Colombia Fish of French Guiana Fish of Guyana Fish of Suriname Fish of Venezuela Catfish genera Freshwater fish genera