Eurycheilichthys limulus Reis & Schaefer, 1998

Reis, Roberto E., 2017, Unexpectedly high diversity in a small basin: A taxonomic revision of Eurycheilichthys (Siluriformes: Loricariidae), with descriptions of seven new species, Neotropical Ichthyology 15 (1), No. e 160068, pp. 1-28 : 6-9

Eurycheilichthys limulus Reis & Schaefer, 1998

Fig. 6; Tabs. 1, 3, 4

Eurycheilichthys limulus Reis & Schaefer, 1998: 15 , fig. 7. Type locality: Rio Jacuí on road RS-010, between Marau and Passo Fundo, 28°18’S, 52°18’W, Rio Grande do Sul State, Brazil.

Neotropical Ichthyology, 15(1): e160068, 2017 Roberto E. Reis

Diagnosis. Eurycheilichthys limulus is distinguished from all congeners by having the pectoral girdle widely exposed ventrally ( Fig. 2b; vs. pectoral girdle exposed only laterally; Figs. 2a, c-i), and, except for E. castaneus , by possessing a body and head plain dark brown in color, without blotches or spots, and with thin light stripes from the snout tip crossing above the eye and predorsal area (vs. body and head with a combination of dark blotches and spots). It is distinguished from E. castaneus by having the upper lobe of the caudal fin mostly hyaline (vs. upper caudal-fin lobe plain brown), and the spine and rays of the dorsal fin spotted (vs. spine and rays of the dorsal fin plain brown). Eurycheilichthys limulus is further distinguished from E. luisae , E. planus , and E. vacariensis by the abdomen being fully covered by small platelets (vs. naked, partially plated with a middle stripe of platelets, or incompletely covered with granular platelets), and by possessing 27-28 plates in middle lateral series (vs. 23-26 plates); from E. luisae and E. pantherinus by the lower lip not extending to the anterior margin of the pectoral girdle (vs. lower lip clearly extending past the anterior margin of the pectoral girdle) and by a narrower cleithral width (23.8-26.8 vs. 27.3-34.0% SL); from E. coryphaenus by possessing 27-28 plates in middle lateral series (vs. 25-26 plates), and by having the parieto- supraoccipital without conspicuous elevation (vs. parietosupraoccipital conspicuously elevated); from E. paucidens by possessing numerous (23-33) accessory teeth on the premaxilla in several irregular series (vs. 2-10 accessory teeth on premaxilla in one irregular series); and from E. apocremnus by the narrower cleithral width (23.8-26.8 vs. 28.4-31.8% SL).

Distribution and habitat. Eurycheilichthys limulus is known from several localities in the upper rio Jacuí basin, in central Rio Grande do Sul, Brazil ( Fig. 7). The species is very common and found in nearly every creek with medium to fast flowing water and a substrate covered with stones or sand. Individuals are also commonly collected in the leaves of grasses and other marginal vegetation.

Conservation status. Eurycheilichthys limulus is frequent and abundant in the upper rio Jacuí basin. Despite the relatively small Extent of Occurrence (EOO) of approximately 8,300 km 2, the presence of hydroelectric dams and extensive agriculture that occur in that basin, no specific threats were detected, and the species can be categorized as Least Concern (LC) according to IUCN criteria (IUCN, 2016).

Material examined. Brazil: Rio Grande do Sul State: upper rio to rio Ingaí, ca. 300m SW of Fazenda Colorados, Fortaleza dos Jacuí drainage : MCP 20283, holotype, 43.6 mm SL, rio Jacuí on Valos (28º54’29”S 53º17’8”W) . MCP 21465, 1 , 35.8 mm SL, road RS-010, between Marau and Passo Fundo (approx. 28º18’S arroio Lageado Fortaleza ca. 5 km NE of Fortaleza dos Valos, 52º18’W) . MCP 13086, 46 paratypes, 20.0- 48.5 mm SL, 2 c&s Fortaleza dos Valos (28º46’45”S 53º11’15”W) . MCP 21270, 15 , 31.6-42.2 mm SL, collected with the holotype . MCP 14528, 1 32.2-48.6 mm SL, arroio Passo das Éguas, on road between Tunas paratype, 40.2 mm SL, rio Umbu at Victor Graeff (approx. 28º35’S and Jacuizinho , Tunas (29º03’03”S 53º01’02”W). MCP 21532, 4 , 52º45’W) . MCP 22181, 10 , 23.4-46.2 mm SL, rio Jacuí on road RS- 29.0- 44.5 mm SL, creek crossing road BR-386 between rio Jacuí 324, between Passo Fundo and Marau, Passo Fundo (28º18’45”S and exit to Ibirapuitã , Ibirapuitã (28º36’40”S 52º36’31”W). MCP 52º18’28”W) . MCP 22195, 3 , 34.0- 48.5 mm SL, arroio Pinheiro 21475, 26, 27.0- 47.5 mm SL, arroio Bonito, on road between Torto, on road between Capinzal and Santa Gema, Passo Fundo Cruz Alta and Ibirubá , Ibirubá (28º38’08”S 53º13’33”W) . MCP (28º22’23”S 52º26’38”W) . MCP 22252, 17 , 22.6-46.9 mm SL, 22126, 13, 35.0- 45.4 mm SL, rio da Glória, ca. 1.5 km East of arroio Carreta Quebrada, ca. 8 km SSE of Capinzal, Passo Fundo road BR-386, between Tio Hugo and Carazinho , Santo Antônio (28º26’48”S 52º23’4”W) . MCP 21500, 3 , 39.3-48.9 mm SL, rio do Planalto (28º21’02”S 52º43’16”W) . MCP 22210, 6 , 22.4 - 40.9 Espraiado at road BR-386 between Soledade and Passo Fundo, mm SL, arroio Estivinha, between Carreta Quebrada and Nicolau Soledade (28º43’20”S 52º33’33”W) . MCP 21214, 1 , 35.3 mm SL, Vergueiro, Nicolau Vergueiro (28º29’18”S 52º23’12”W) . MCP arroio Despraiado, on road between Soledade and Arvorezinha, ca. 22179, 1, 37.9 mm SL, arroio Erval, on road BR-386, between 4 km SW of road BR-386, Soledade (28º48’26”S 52º25’47”W) . Tio Hugo and Carazinho, Santo Antônio do Planalto (28º27’02”S MCP 22700, 48 , 17.9-46.7 mm SL, 2 c&s, 44.6-47.3 mm SL, 52º39’43”W) . MCP 22749, 13 , 28.3-43.9 mm SL, rio Pinheirinho, rio Passo Novo, on the way out from Cruz Alta to Ibirubá, Cruz on road between Saldanha Marinho and Carazinho , Saldanha Alta (28º38’43”S 53º33’35”W) . MCP 22693, 34 , 24.5-47.4 mm Marinho (28º23’39”S 53º03’11”W) . MCP 21446, 11 , 34.9 - 49.8 SL, rio Lageado das Pedras, ca. 6.2 km East of Cruz Alta on road mm SL, creek tributary to Passo Real hidroelectric dam, ca.7.1 to Ibirubá, Cruz Alta (28º38’41”S 53º30’30”W) . MCP 22167, 2 , km NNW of Fortaleza dos Valos on road to Santa Clara do Ingaí, 34.5-42.1 mm SL, arroio Pessegueiro, on road RS-153, between Quinze de Novembro (28º44’31”S 53º13’01”W) . MCP 41143, Ernestina and Passo Fundo , Ernestina (28º25’4”S 52º32’55”W) . 26, 20.1-49.0 mm SL, arroio Passo dos Buracos on road from MCP 22170, 20 , 22.1-47.5 mm SL, creek ca. 2 km West of Julio de Castilhos to Cruz Alta, Julio de Castilhos (29º06’48”S Ernestina, Ernestina (28º29’45”S 52º35’33”W). MCP 35120, 14 53º39’01”W) . MCP 22760, 29 , 28.1-47.9 mm SL, arroio Tapiaia, tis, 28.1-43.5 mm SL, riacho Chifranzinho, on road from Ernestina ca. 13 km N of Julio de Castilhos, on road to Cruz Alta, Júlio de to Passo Fundo, Ernestina (28º22’14”S 52º30’37”W) . MCP 21507, Castilhos (29º06’49”S 53º39’04”W) . MCP 22774, 7 , 27.3 - 44.2 31, 25.7-38.5 mm SL, creek tributary to rio Lageado Fortaleza, ca. mm SL, arroio das Figueiras, on road from Cruz Alta to Saldanha 3 km East of Fortaleza dos Valos, Fortaleza dos Valos (28º47’39”S Marinho , Santa Bárbara do Sul (28º26’39”S 53º12’37”W). MCP 53º12’17”W) . MCP 21521, 11 , 27.9-48.9 mm SL, creek tributary 22218, 3, 32.5-43.5 mm SL, arroio Quebra Dentes at Quebra Dentes, Nicolau Vergueiro (28º36’9”S 52º27’23”W) . MCP 22213, 8 , 31.4-46.7 mm SL, creek tributary to arroio Resvalador in Arroio Bertolino , Nicolau Vergueiro (28º32’47”S 52º25’42”W) . MCP 22153, 9 , 23.3-49.3 mm SL, arroio Resvalador in Arroio Bertolino , Nicolau Vergueiro (28º32’54”S 52º25’59”W) . MCP 35118, 8 tis, 27.8-46.0 mm SL, arroio Pinheiro Torto, na estrada de Ernestina para Passo Fundo, Passo Fundo (28°18’24”S 52°28’13”W) .

Genseq- 4 16S. MCP 35118; GenBank accession number KX355630 .

Genseq-4 RAG1, RAG2. Sequence data published by Cramer et al. (2011) for RAG1 ( MCP 21270; GenBank accession number GQ214579 ) and RAG2 ( MCP 21270; GenBank accession number GQ225453 ).

Genseq-4 COI. Sequences deposited in GenBank by Cristian Cramer for COI ( MCP 21270; GenBank accession numbers EU370989.1 and EU370990.1).