The species of Hemiancistrus (Siluriformes: Loricariidae) from Ecuador Author Provenzano, Francisco Author Barriga, Ramiro text Zootaxa 2017 4272 2 221 235 journal article 32959 10.11646/zootaxa.4272.2.4 1a827faf-4ba6-4e0a-99f7-134104627212 1175-5326 583853 1B38C172-5A2C-478F-9836-5B25DB956261 Key to the species commonly referred to as Hemiancistrus in Ecuador 1a Cheek region with four to eight, small, scarcely developed odontodes, visible mostly on adult specimens. These odontodes are associated with a bony plate, with reduced mobility or immobile. Dorsal fin folded reaches the origin of adipose fin in juveniles, or very close in adults. Caudal fin furcate. Santiago River Basin, province of Esmeraldas , NW of Ecuador ............................................................................................. Hypostomus annectens 1b Cheek region with 12 or more developed odontodes, very small in juveniles. These odontodes are associated with connective tissue, they are located behind a bony plate or bony granulations, and are always mobile. Dorsal fin folded does not reach adipose-fin origin. Caudal fin emarginate..................................................................... 2 2a Ventral surface of the head and abdomen covered with small plates or granulations in specimens with 80 mm SL or more. Cheek odontodes 15 or more, well developed, longest (most posterior) greater than eye diameter. Dorsal fin with rounded dark dots arranged in vertical lines just in the middle of interradial membrane. Guayas , Arenillas, Puyango and Zaracay Rivers systems, provinces of Manabí, Los Rios, Guayas and El Oro ..................................... Hemiancistrus landoni 2b Ventral surface of the head and abdomen completely naked in specimens 85 mm SL. Cheek odontodes 12–15, very few developed, longest less than eye diameter. Dorsal fin with irregular dark dots arranged in vertical lines on the interradial membrane close to the rays. Esmeraldas river system, provinces of Pichincha and Esmeraldas ................. Hemiancistrus furtivus