Hemiancistrus

Provenzano, Francisco & Barriga, Ramiro, 2017, The species of Hemiancistrus (Siluriformes: Loricariidae) from Ecuador, Zootaxa 4272 (2), pp. 221-235 : 223

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