Pseudobiotus megalonyx ( Thulin, 1928 ) sensu

153. Pseudobiotus megalonyx ( Thulin, 1928) sensu lato [F]

Hypsibius (subgen. Isohypsibius Thulin 1928 ) augusti (J. Murray 1907) forma megalonyx Thulin 1928 ( Marcus 1939) H. ( I.) augusti (J. Murray, 1907) , forma typica (du Bois-Reymond Marcus 1944) Hypsibius augusti (Murray) (Van der Land 1970)

Pseudobiotus augusti (J. Murray) (Claps 1984)

Pseudobiotus augusti (Murray, 1907) ( Claps & Rossi 1988, Rossi and Claps 1991) Pseudobiotus augusti (Murray, 1907) ( Rossi & Claps 1991)

Terra typica: Sweden (Europe)

Argentina:

• 29°11′S, 58°04′W; 100 m asl: Corrientes Province, near Mercedes, cerro Pajarito, laguna, algae ( Chara sp.). Claps & Rossi (1988), Rossi & Claps (1991)

• 31°39′S, 64°59′W; 1,050 m asl: Córdoba Province, Toro Muerto, sample on plant ( Potamogeton af. berteroanus). Rossi & Claps (1991)

• 33°37′S, 60°15′W; 50 m asl: Buenos Aires Province, Arroyo Manantiales, benthos samples. Rossi & Claps (1991)

• 33°56′S, 59°21′W; 0 m asl: Buenos Aires Province, Rio Areco, plankton samples. Rossi & Claps (1991)

• 33°57′S, 59°43′W; 0 m asl: Buenos Aires Province, Arroyo Burgos, benthos, plankton samples and on plant ( Hydrocotyle ranunculoides L.). Rossi & Claps (1991)

• 34°33′S, 59°07′W; 0 m asl: Buenos Aires Province, Rio Luján, on plant ( Alternanthera philoxeroides (Martius) Grisebach ). Rossi & Claps (1991)

• 34°53′S, 57°59′W; 0 m asl: Buenos Aires Province, Arroyo del Gato [Arroyo el Gato], benthos samples. Rossi & Claps (1991)

• 34°54′S, 57°56′W; 0 m asl: Buenos Aires Province, La Plata, Jardín Zoológico de la Plata, lentic microlimnotopes, on plant ( Nymphaea sp.). Rossi & Claps (1991)

• 34°56′S, 58°04′W; 0 m asl: Buenos Aires Province, Arroyo Rodríguez, plankton sample. Rossi & Claps (1991)

• 35°01′S, 57 ° 31′W; 0 m asl: Buenos Aires Province, Punta Atalaya, Rio de la Plata, zooperiphyton on plant ( Scirpus ( Schoenoplectus) californicus (Meyer) Steud. ). Claps (1984)

• 38°08′S, 61°48′W; 250 m asl: Buenos Aires Province, arroyo in Sierra de la Ventana, stones in the water. Rossi & Claps (1991)

Brazil:

• 23°30′S, 46°48′W; 750 m asl: São Paulo State, tributaries to Rio Tiet, mosses or aquatic plants. du Bois-Reymond Marcus (1944)

Peru:

• 15°43′S, 70°43′W; 4,200 m asl: Puno Region, Lake Titicaca, edge of Laguna Tejane, mud. Marcus (1939)

Suriname:

• 05°52′N, 55°12′W; 0 m asl: Weg naar Zee at Paramaribo, swamp with plants ( Cyperus giganteus Vahl. and Montrichardia arborescens Schott ), pH 7.5, soil and plankton sample No. 292. Van der Land (1970)

• 05°48′N, 55°10′W; 0 m asl: Paramaribo District, Latour near Paramaribo, ditch, ( Eichornia ) and other plants (grass), soil and plankton sample (2 samples Nos. 313 & 314). Van der Land (1970)

• 05°46′N, 55°20′W; 0 m asl: Saramacca District, Uitkijk, dich (drainage channel 19) with floating aquatic plants (especially Eichornia ) and between roots of plant ( Eichornia ), pH 7.5, plankton sample (2 samples Nos. 293 & 294). Van der Land (1970)

• 05°46′N, 55°12′W; 0 m asl: Wanica District, Vierkinderenweg, S of Paramaribo, trench in rice field, soil sample No. 316. Van der Land (1970)

• 05°46′N, 55°12′W; 0 m asl: Wanica District, Noordbergerweg, S of Paramaribo, pond between rice fields overgrown with Eichornia , soil sample No. 317. Van der Land (1970)

• 05°46′N, 55°10′W; 0 m asl: Wanica District, Livorno near Paramaribo, swamp, pH 5.9, soil and plankton sample No. 297. Van der Land (1970)

• 05°46′N, 55°09′W; 0 m asl: Wanica District, bank of Tout Lui Faut Kanaal, pH 6.5, soil and plankton sample No. 298 lost. Van der Land (1970)

• 05°44′N, 55°10′W; 0 m asl: Wanica District, Houttuin near Paramaribo, puddle, pH 6.3, plankton sample (2 samples Nos. 300 & 301). Van der Land (1970)

• 05°42′N, 55°14′W; 0 m asl: Wanica District, Lelydorp, marsh and swamp with floating turf, pH 5.9, soil and plankton sample Nos. 302 (lost) & 303. Van der Land (1970)

• 05°36′N, 55°12′W; 0 m asl: Para District, Onverwacht, swamp with Montrichardia arborescens Schott , pH 5.9, soil and plankton sample No. 306. Van der Land (1970)

• 05°36′N, 55°08′W; 0 m asl: Para District, Onverdacht, bauxite lake, soil and plankton sample No 323. Van der Land (1970)

Uruguay:

• 31°23′S, 57°57′W; 50 m asl: Salto Department, Salto, mosses or lichens on rocks, trees or posts or aquatic macrophytes. Claps & Rossi (1997)

Record numbers: Argentina: 11, Brazil: 1, Peru: 1, Suriname: 11, Uruguay: 1; total: 25.

Remarks: Reports for both Pseudobiotus augusti and Isohypsibius augusti are included here as taxonomic confusion of the original P. augusti description has left the records split between Pseudobiotus and Thulinius . It is highly probable that records belong to both genera (Bertolani et al. 1999, Nelson et al. 1999). Marcus (1939) is the only Neotropical report for an otherwise Palaearctic Pseudobiotus megalonyx ( McInnes 1994a) , suggesting all South American records require re-examination.