Pygidianops Myers, 1944

de Pinna, Mário C. C. & Kirovsky, Alexandre L., 2011, A new species of sand-dwelling catfish, with a phylogenetic diagnosis of Pygidianops Myers (Siluriformes: Trichomycteridae: Glanapteryginae), Neotropical Ichthyology 9 (3), pp. 493-504 : 502

Pygidianops Myers, 1944

Type species: Pygidianops eigenmanni, Myers, 1944 .

Revised diagnosis. Glanapterygine trichomycterids uniquely diagnosed by a hypertrophied symphyseal joint and associated ligament in the lower jaw; an elongate, laterallydirected, process on the dorsal surface of the premaxilla; a rotated lower jaw, where the surface normally facing laterally in other glanapterygines is instead directed ventrally. Further distinguished from its closest relative, Typhlobelus , by the snout relatively short, not prolongued into a duck-bill shape; the presence of numerous teeth on each premaxilla (vs. 1-4); the presence of well-differentiated (and partly ossified) basibranchials and hypobranchials (vs. elements mostly undifferentiated or absent); the palatine large and oriented in parallel to the neurocranium (vs. palatine small, club-shaped and oriented obliquely to the neurocranium); the posterior margin of the hyomandibula lacking a process (vs. large pointed process posteriorly on posterior margin of hyomandibula); and the premaxilla articulating with the anterior end of the mesethmoid (vs. articulating with the shaft of the mesethmoid). Further distinguished from Listrura and Glanapteryx by the presence of metapleural keels along the edges of abdomen, the reduction or lack of dark integument pigmentation and the presence of a long dorsal-fin fold extending along most of dorsal margin of body. Further distinguished from Listrura by the short pectoral fin, the absence of opercular and interopercular odontodes and the absence of dorsal fin.

Included species: P. eigenmanni Myers, 1944 ; P. cuao Schaefer, Provenzano, de Pinna & Baskin, 2005 ; P. magoi Schaefer, Provenzano, de Pinna & Baskin, 2005 ; and P. amphioxus , new species.

Comparative Material Examined. Glanapteryx anguilla, MZUSP 36530, 19 (2 c&s), 33.7-63.2 mm SL, Brazil, Amazonas, rio Negro, igarapé São João, near Tapurucuara, 00°24’S 65°02’W. Glanapteryx niobium, INPA 12421, holotype, 55.3 mm SL, Brazil, Amazonas, Pico da Neblina National Park, Morro dos Seis Lagos, lago Esperança, 00°17’N 66°41’W. Listrura camposi, MZUSP 95189, 17 (3 c&s), 19.8-46.2 mm SL. Listrura nematopteryx, MZUSP 36974, holotype, 26.9 mm SL, Brazil, Rio de Janeiro, Piabetá, marsh which joins Ribeirão Imbariê (tributary to rio Estrela), near 58 km mark of old road to Petrópolis, 22°36’36”S 43°11’26”W; MZUSP 36975, 12, paratypes, 16.3-36.7 mm SL, collected with holotype; MZUSP 37138, 8 (c&s), ca. 14-28 mm SL, collected with holotype. Listrura picinguabae, MZUSP 106807, 6 (4 c&s), 33.1-41.7 mm SL, Brazil, São Paulo, Ubatuba, coastal creek at Picinguaba. Listrura tetraradiata, MNRJ 19064, 10 (2 c&s), 15.0- 44.2 mm SL, Brazil, Rio de Janeiro, Saquarema, Palmital, Hotel Fazenda Barra da Castelhana. Pygidianops cuao, MZUSP 81769 (ex-AMNH 232970), 4 (1 c&s), paratypes, 13.4-19.0 mm SL, Venezuela, Amazonas, río Cuao at Raudal Guacamaya, 8.1 miles upstream from Raudal El Danto, 05°07.71’N 67°31.53’W; MZUSP 82103, 5 (1 c&s), 13.4-19.0 mm SL, paratypes, same data as MZUSP 81769; MZUSP 82104, 3, paratypes, 10.6-18.4 mm SL, Venezuela, Estado Amazonas, río Cuao at Isla de Cielo, 21.3 km upstream from Raudal El Danto, 05°11.01’N 67°31.11’W. Pygidianops eigenmanni, CAS 11121, 2 (1 c&s), paratypes, 13.3-18.5 mm SL, Brazil, Amazonas, São Gabriel da Cachoeira, rio Negro, rock pools below São Gabriel rapids. Pygidianops magoi, MZUSP 84303, 2, paratypes, 15.0- 15.3 mm SL, Venezuela, Delta Amacuro, río Orinoco at Puerto Cabrian, 08°34’48”N 62°15’54”W; MZUSP 84304, 1 (c&s), paratype, 11.4 mm SL, Venezuela, Bolívar, río Orinoco, 08°18.3’N 62° 56.1’W; MZUSP 84306, 1ex, paratype, 15.7 mm SL, Venezuela, Delta Amacuro, río Orinoco downstream from Puerto Cabrian, 08°34’N 62°15’W. Typhlobelus guacamaya, MZUSP 81770, 3 (1c&s), paratypes, 23.3-25.6 mm SL, Venezuela, Amazonas, río Cuao, at Raudal Guacamaya, 13km upstream from Raudal El Danto, 05°07.71’N 67°31.53’W. Typhlobelus lundbergi, MZUSP 84305, 3 (1c&s), paratypes, 20.8-22.0 mm SL, Venezuela, Bolivar, río Orinoco, 08°18’18”N 62°56’06”W. Typhlobelus macromycterus, MNRJ 12129, holotype, 21.6 mm SL, Pará, rio Tocantins, near city of Tucuruí. Typhlobelus cf. macromycterus, MZUSP 106846, 5 (1 c&s), 24.1-27.1 mm SL, Brazil, Pará, Belo Monte, paraná in rio Xingu, 03°06’06”S 51° 42’49”W. Typhlobelus ternetzi, CAS 11119, 2 (1c&s), paratypes, 22.3 mm SL, Brazil, Amazonas, São Gabriel da Cachoeira, rio Negro, rock pools below São Gabriel rapids. Typhlobelus sp. , INPA 12929, 7 (2 c&s), 20.0- 30.1 mm SL, Brazil, Pará, Senador José Porfírio, rio Xingu at Arroz Cru. Representatives examined of other Trichomycteridae and loricarioids are listed in de Pinna (1992).