Rhadinoloricaria Isbrücker & Nijssen, 1974

Provenzano-Rizzi, Francisco & Barriga-Salazar, Ramiro, 2020, New finding of Rhadinoloricaria macromystax (Siluriformes: Loricariidae) redescription of the genus and description of a new species from Ecuador, Zootaxa 4779 (4), pp. 485-500 : 487

Rhadinoloricaria Isbrücker & Nijssen, 1974

Rhadinoloricaria Isbrücker & Nijssen, 1974 , Beaufortia, 22(290):73.

Type species: Loricaria macromystax Günther, 1869 by original designation.

Diagnosis. Genus Rhadinoloricaria belongs to the subfamily Loricariinae , tribe Loricariini , subtribe Loricariina , Loricaria - Pseudohemiodon group ( Covain et al. 2016), and has the following unique combination of characters: Snout projected, spatula shaped. Maxillary barbel very long, surpassing pectoral-fin base. Teeth present in both jaws, small, always visible, and few, usually four premaxillary teeth, and eight dentary teeth. Edge and surface of lips with barbelets, in some cases, lower lip surface may have barbelets and papillae.Abdominal plating variable. Buccal ornamentation composite three to five conical barbelets unbranched and differently sized, located external side to each premaxilla. Barbelets seem rooted in wide papillae. Inside mouth, behind premaxillae, just at center, there is one thick barbelet, elongate, which ramifies into three or four conical arms similarly sized and unbranched.

Remarks. Pseudohemiodon group (sensu Covain et al. 2008) comprises seven genera: Apistoloricaria , Crossoloricaria , Dentectus , Planiloricaria , Pseudohemiodon , Pyxiloricaria and Rhadinoloricaria . Rhadinoloricaria is distinguishable from all other genera by its elongated, spatula-shaped snout vs. snout short and rounded, not noticeably elongated. Furthermore, Rhadinoloricaria is recognized from all other genera, except Apistoloricaria by having extraordinary long maxillary barbels, usually reaching the posterior border of pectoral-fin vs. maxillary barbels long, but never surpassing half of length of adpressed pectoral-fin. From Apistoloricaria by presence of one thick, elongate barbelet, branched into three or four conical arms, unbranched, often same sized, behind premaxillae vs. six or seven elongated, branched and unbranched barbelets, behind premaxillae. From Dentectus by absence of elongated, unbranched, cylindrical barbelets originating on upper lip that cover the mouth, and by upper jaw teeth visible at naked eye vs. presence of elongated, unbranched, cylindrical barbelets originating in upper lip that cover the mouth, and upper jaw teeth, very minute, not observable by the naked eye. From Planiloricaria by teeth present in both jaws vs. teeth absent in upper jaw. From Pseudohemiodon by presence of one thick, elongate barbelet, branched into four or three conical arms, unbranched, often similarly sized, behind premaxillae vs. presence of one unbranched barbelet, elongate and cylindrical, behind premaxillae. From Pyxiloricaria by branchiostegal membrane completely smooth vs. anterior margin of branchiostegal membrane with a large, fleshy, wrinkled flap. From trans- Andean Crossoloricaria , by the presence, behind premaxillae, of one thick barbelet, elongate, branched into three or four conical arms same sized and unbranched vs. presence of two elongate, cylindrical, unbranched barbelets, behind premaxillae. From cis-Andean Crossoloricaria , C. bahuaja and C. rhami by lower lip surface narrower and covered with barbelets, sometimes with barbelets and papillae vs. lower lip surface wider and covered with papillae, normally. From C. bahuaja by presence of one thick barbelet, elongate, branched into three or four conical arms, unbranched, and same sized, behind premaxillae vs. behind premaxillae, presence of one thick barbelet, elongate, branched into three or four conical arms, unbranched, the anterior arm elongated, longer than the two posterior. From C. rhami by maxillary barbel long, surpasses pectoral-fin base, and abdomen covered, totally or partially with plates, in adults vs. maxillary barbel short, reach gill openings, and abdomen totally covered, in adults.