Aphanotorulus Isbrücker and Nijssen 1983

Ray, C. Keith & Armbruster, Jonathan W., 2016, The genera Isorineloricaria and Aphanotorulus (Siluriformes: Loricariidae) with description of a new species, Zootaxa 4072 (5), pp. 501-539 : 507

Aphanotorulus Isbrücker and Nijssen 1983

Aphanotorulus Isbrücker & Nijssen, 1983: 105 . Type species: Aphanotorulus frankei Isbrücker & Nijssen, 1983 . Type by original designation.

Squaliforma Isbrücker & Michels , in Isbrücker et al., 2001: 22. Type species: Hypostomus horridus Kner, 1854 . Type by original designation.

Diagnosis. Aphanotorulus can be separated from Hypostomus by having hypertrophied odontodes on the heads and lateral plates of nuptial males (vs. hypertrophied odontodes absent) and from all sympatric Hypostomus by having a light tan background (vs. dark tan to brown), from Isorineloricaria by having caudal peduncles that do not become greatly lengthed with size and that are oval in cross section (vs. caudal peduncle proportions that get proportionately longer with size and that become round in cross-section), and by having small dark spots (less than half plate diameter) on a light tan background (vs. spots almost as large as lateral plates on a nearly white background. Aphanotorulus can be further separated from the taxa recognized in Armbruster’s Corymbophanini by having an adipose fin (vs. adipose fin replaced by postdorsal ridge of 13–17 azygous plates); from the Corymbophanini and Rhinelepinae by having the iris operculum (vs iris operculum absent); from the Rhinelepinae by lacking exposure of the coracoid strut (vs. coracoid strut exposed, supporting odontodes), and by having the anal fin I,4 (vs. I,6); from the Pterygoplichthyini by having the stomach attached via the dorsal mesentery only (vs. connected to the lateral abdominal walls by a connective tissue sheet) and by usually having one plate between the supra-preopercle and opercle, rarely two (vs. two to three); from the Ancistrini (except Spectracanthicus murinus and some Pseudancistrus ) and the Pterygoplichthyini by having the cheek plates evertible to about 30° to the head and generally lacking hypertrophied odontodes on the cheek plates with the only exception nuptial males in a few species (vs. cheek plates evertible to 70° or more and hypertrophied odontodes usually present); from Spectracanthicus by having the dorsal and adipose fins separate (vs. connected by a posterior extension of the dorsal fin), and from Pseudancistrus without evertible cheek plates by having three plates between the head and dorsal fin (including the nuchal plate, vs. four or more).