unbranched in midlateral, extending from the vertical through the pectoral fin base to the caudal peduncle; however, in D. royeroi and D. sauli, it is incomplete, interrupted, and restricted to the abdomen. The dorsal profile of the body tends to be nearly straight to slightly convex; the ventral profile is slightly convex to convex at the abdomen and is usually approximately straight but posterodorsally slanted along the base of the anal fin. Except for D. macilenta which has a distinctly rounded head and snout, the head of Denticetopsis species in profile is acutely triangular overall with a bluntly pointed snout. The eyes are situated on the sides of the head and are visible from above but not from below. The mouth is inferior, the width from approximately one-half to two-thirds of the length of the head. In most species of Denticetopsis, the medial mental barbels are slightly shorter than the lateral mental barbels, with the latter approximately equal in length to the slender maxillary barbels. However, in C. sauli both pairs of mental barbels are approximately the same length and shorter than the maxillary barbels, and in C. royeroi all three pairs of barbels are approximately the same length. The dorsal fin is moderately large overall. The dorsal fin spinelet is absent. The anal fin base is usually moderately long but may be long. The pelvic fins are usually moderate but may be moderately long, though in D. sauli they are short. The pectoral fin length is about one-half the length of the head length. Denticetopsis species range from 1.8–6.7 centimetres (.71–2.6 in) SL. Sexual dimorphism in the shape of the dorsal, pectoral, and anal fins has not been described in species of Denticetopsis, despite the presence of these traits in Cetopsis and Cetopsidium. It is possible that male D. praecox reach sexual maturity at a smaller size than females of the same species. Ecology D. praecox have been found in a cobble-pebble habitat of black water streams that ranged in pH from 4.3–5.0. Stomachs of two examined specimens of this species contained larval chironomids and other larval insect remains. References Cetopsidae Fish of South America Vertebrates of Guyana Fish of Venezuela Catfish genera Freshwater fish genera