Eurycheilichthys luisae, Reis, 2017

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 : 15-19

Eurycheilichthys luisae , new species

urn:lsid:zoobank.org:act:A1DA6253-4693-47F8-A5F9-8ED7B6886289

Fig. 12; Tabs. 2-4

Eurycheilichthys sp. 2 .- Reis, Carvalho, 2007: 84 [listed]. Eurycheilichthys sp. 1 .- Cramer et al., 2011: 48 [phylogeny].

Neotropical Ichthyology, 15(1): e160068, 2017 A revision of Eurycheilichthys

Holotype. MCP 40662, 42.5 mm SL, male, Brazil, Rio

Grande do Sul, Arvorezinha, arroio Três Pontes, rio Taquari basin, on road from Soledade to Arvorezinha, ca. 18 km SE of road BR-386 (28º48’24”S 52º18’14”W), 21 May 2004, R. E. Reis et al.

Paratypes. Brazil: Rio Grande do Sul: upper rio Taquari drainage : MCP 35057, 10 , 34.2-44.3 mm SL (3, 40.4- 44.3 mm SL), 16 tis, 33.8-42.9 mm SL , MZUSP 92424 , 3 , 35.3-42.7 mm SL , AMNH 238573 , 3 , 38.5-43.8 mm SL, collected with the holotype. MCP 25566, 17 , 24.8 -43.0 mm SL, 2 c&s, 37.9-38.5 mm SL (10, 37.7-43.0 mm SL), arroio Jabuticaba near its mouth into rio das Antas, Veranópolis (29º01’13”S 51º31’41”W), 19 Mar 2000 , R. E. Reis et al . MCP 35058, 12 , 28.9-47.3 mm SL (10, 37.1-47.3 mm SL), arroio Fãozinho at Vila Nova, Barros Cassal (29º03’30”S 52º30’58”W), 21 May 2004 , R. E. Reis et al . MCP 21208, 11 , 28.4-45.4 mm SL (3, 44.2-45.4 mm SL), arroio Jeremias, on road from Soledade to Arvorezinha, ca. 25 km SE of road BR-386, Arvorezinha (28º49’44”S 52º14’35”W) , 25

Aug 1998, J. F. Pezzi et al. MCP 21207, 12, 30.3-47.7 mm

SL (3, 41.4-47.7 mm SL), arroio Três Pontes, on road from Soledade to Arvorezinha, ca. 18 km SE of road BR-386, Arvorezinha (28º48’24”S, 52º18’14”W), 25 Aug 1998, J. F. Pezzi et al. MCP 21679, 3 , 31.9-35.2 mm SL, 1 c&s, 33.6 mm SL, arroio Jabuticaba, at Monte Claro, Veranópolis (29º01’15”S 51º34’55”W), 15 Oct 1998, W. Bruschi Jr. MCP 25490, 1 , 40.9 mm SL, arroio Jabuticaba, at Monte Claro, Veranópolis (29º01’15”S 51º34’55”W), 5 Mar 1999, W. Bruschi Jr. MCP 43968, 12 , 21.7-44.3 mm SL, arroio Governador, tributary to rio das Antas, Bom Jesus (28º44’23”S 50º40’42”W), 19 Dec 2008, J. F. Pezzi & E. H. L. Pereira .

Genseq- 2 16S. MCP 35057; GenBank accession number KX355634 .

Genseq-2 COI. Sequences deposited in GenBank by Cristian Cramer for COI ( MCP 21207; GenBank accession numbers EU370995 and EU370998 ) .

Non-types. Brazil: Rio Grande do Sul: upper rio Taquari drainage: MCP 22150, 1, 39.7 mm SL, arroio dos gordos, on road RS-324 between Casca and Nova Araça, Paraí, (28º38’42”S 51º41’36”W), 20 Jan 1999, R. E. Reis et al. MCP 22225, 2, 35.3-45.6 mm SL, rio Carreiro, on road between São Domingos do Sul and Paraí, São Domingos do Sul (28º33’51”S 51º49’45”W), 20 Jan 1999, R. E. Reis et al. MCP 22247, 8, 20.1-42.3 mm SL, arroio Quebra Perna, on road between São Domingos do Sul and Paraí, São Domingos do Sul (28º34’01”S 51º50’36”W), 20 Jan 1999, R. E. Reis et al. MCP 23046, 2, 17.6-20.0 mm SL, rio Turvo, on road from Vila Flores to Antonio Prado, Antonio Prado (28º52’19”S 51º26’57”W), 21 Jan 1999, R. E. Reis et al. MCP 23051, 1, 22.7 mm SL, arroio Palmara, upstream from mouth into rio das Antas near Nossa Senhora das Graças, on road from Antonio Prado to Caxias do Sul, Antônio Prado (28º58’04”S 51º12’34”W), 21 Jan 1999, R. E. Reis et al. MCP 29953, 7, 25.0- 27.5 mm SL, rio Ituim, downstream Saltinho waterfall, Antonio Prado (approx. 28º37’S 51º21’W), 27 Jun 2002, A. R. Cardoso & V. A. Bertaco. MCP 35045, 5, 38.1-41.9 mm SL, 11 tis, 23.2-40.4 mm SL, arroio Quebra Perna near Santa Gema, São Domingos do Sul (28º34’06”S 51º50’35”W), 22 May 2004, R. E. Reis et al. MCP 35058, 14 tis, 33.7-40.5 mm SL, arroio Fãozinho at Vila Nova, Barros Cassal (29º03’30”S 52º30’58”W), 21 May 2004, R. E. Reis et al. MCP 35122, 4 tis, 24.9-45.0 mm SL, arroio Jeremias, on road from Soledade to Arvorezinha, ca. 25 km East of road BR-386, Arvorezinha (28º49’44”S 52º14’35”W), 21 May 2004, R. E. Reis et al. MCP 36837, 5 tis, 31.3-43.4 mm SL, arroio Jabuticaba near its mouth into rio das Antas, Veranópolis (29º01’06”S 51º31’37”W) 3 Sep 2004, T. P. Carvalho et al. MCP 40937, 1, 40.9 mm SL, arroio Guabiju, on road between Guabiju and Vila São Jorge, Guabiju (28º30’49”S 51º41’22”W), 24 Oct 2006, T. P. Carvalho & V. A. Bertaco. UFRGS 6425, 1, 30.4 mm SL, creek near mouth of rio Carreiro, Cotiporã (28º57’32”S 51º45’10”W), 8 Oct 2003, J. Anza & F. Vilella. UFRGS 6418, 11, 31.2-44.8 mm SL, creek tributary to rio Carreiro at Linha Emilia, Dois Lageados (28º56’08”S 51º46’59”W), 7 Oct 2003, J. Anza & F. Vilella. UFRGS 6422, 2, 32.9-33.8 mm SL, rio Carreiro near mouth of arroio Sabiá at Linha São Pedro, Fagundes Varela (28º53’04”S 51º47’28”W), 5 Oct 2003, J. Anza & F. Vilella.

Diagnosis. Eurycheilichthys luisae is distinguished from all congeners, except E. pantherinus , by possessing a very large lower lip extending to or beyond the anterior margin of the pectoral girdle (vs. lower lip not reaching the anterior margin of the pectoral girdle). It is distinguished from E. pantherinus by having the abdomen partially plated with a middle stripe of platelets (vs. completely covered by small platelets), and by the deeper caudal peduncle (10.1-12.5 vs. 7.8-10.2% SL). It is also distinguished from all congeners, except E. planus and E. vacariensis , by an abdomen partially plated with a middle stripe of platelets (vs. abdomen fully covered by small platelets). It is distinguished from E. apocremnus , E. castaneus , E. limulus , and E. paucidens by possessing 23-25 plates in middle lateral series (vs. 27-30 plates, occasionally 26). Eurycheilichthys luisae is further distinguished from E. castaneus and E. limulus by the color pattern of its body and a head covered with many regularly small and roundish dark spots (vs. body and head plain dark brown, without blotches or spots, and with a light stripe from snout tip, crossing above the eye and predorsal area); from E. limulus by the wider cleithrum (28.6-34.0 vs. 23.8-26.8% SL); from E. coryphaenus by the parieto-supraoccipital lacking a distinct elevation (vs. parieto-supraoccipital conspicuously elevated); from E. planus by the deeper caudal peduncle (10.1-12.5 vs. 8.9- 10.0% SL); from E. vacariensis by the body and head being covered with many small, roundish, dark spots (vs. large, irregular, dark spots on body, head mostly dark), and by the lower lip extending past the anterior margin of the pectoral girdle (vs. lower lip hardly reaching that point); and from E. paucidens by possessing numerous (26-62) accessory teeth on premaxilla in several irregular series (vs. fewer, 2-10 accessory teeth on premaxilla in one irregular series), and the longer mandibular ramus (11.1- 14.7 vs. 7.0-10.8% HL).

Description. Proportional measurements and counts in Tabs. 2, 3, and 4. Dorsal body profile gently arched from snout tip to parieto-supraoccipital, slightly arched to straight from that point to dorsal-fin origin; parieto-supraoccipital with discrete elevation, more salient in larger individuals. Trunk generally straight and tapering slightly toward caudal-fin base. Trunk and caudal peduncle rounded in cross section, slightly flattened at and behind base of dorsal and anal fins, and compressed caudally. Greatest body depth at parieto-supraoccipital bone or dorsal-fin origin. Head and snout broad and rounded anteriorly, with body progressively narrowing caudally from cleithrum. Interorbital space slightly concave; superior margin of orbits elevated. Snout slightly convex anterior to nares. Nostrils located at posterior terminus of pair of elongate, shallow depressions beginning close to snout tip. Eye comparatively small, orbit diameter 12.1-14.5% HL, dorsolaterally placed.

Pectoral fin of moderate size, spine slightly arched, posterior fin-margin straight; extending to distal third of pelvic fin when depressed. Fleshy flap along posterodorsal margin of pectoral-fin spine in both male and female adults. Pectoral-fin axillary slit present, with large opening ventral to tip of posterior process of cleithrum. Pelvic fin of females short, extending to point midway between anus and analfin origin when depressed. Thickened first pelvic-fin ray of males longer, usually extending to anal-fin origin. Males exhibit well-developed fleshy flap along posterodorsal margin of thickened first pelvic-fin ray. Dorsal-fin origin at vertical line through end of pelvic-fin base; spinelet present, reduced and plate-like; dorsal-fin locking mechanism nonfunctional. Adipose fin absent.

Body entirely covered by dermal plates except for area around anus, opening of swimbladder capsule posteroventrally to compound pterotic, most of the abdomen, and ventral surface of head around lips. Body and head without crests. Coracoid and cleithrum exposed laterally, covered medially by skin and few isolated platelets. Arrector fossa open. Lateral abdominal plates absent. Middle abdominal plates small to granular, irregularly arranged in a middle patch in front of the anal opening that can extend to anterior portion of abdomen, leaving large unplated areas laterally ( Fig. 2f). Posterior tip of parieto-supraoccipital with small patch of larger odontodes than those on remainder of head and predorsal area, especially in smaller individuals. Head and body plates covered with odontodes, these larger on ventral face of first pelvic-fin ray and pectoral spine. Odontodes on head and trunk otherwise of uniform size and distribution, not arranged in conspicuous rows.

Lips roundish and wide, papillose, and extending posteriorly to a point between end of canal-bearing lateral cheek plate and anterior margin of pectoral girdle. Lower lip margin smooth to fringed. Maxillary barbel short, mostly adnate to lower lip. Teeth slender, bifid; major (medial) cusp large, bladelike, and slightly rounded; minor (lateral) cusp minute, pointed. Accessory patch of unicuspid teeth on premaxilla and dentary attached to dermal bone posterior (premaxilla) and anterior (dentary) margin of tooth cup, which encloses main series of emergent and pre-emergent bifid teeth. Accessory teeth large, elongate, sharply pointed, directed posteroventrally (premaxilla) and anteroventrally (dentary).

Color in alcohol. Background color of dorsal surface of head and body light brown with many roundish dark brown dots scattered throughout head and body; dots smaller and more concentrated on head; yellowish tan, mostly unpigmented ventrally except for caudal peduncle. Hypertrophied odontodes on tip of parieto-supraoccipital bone lighter than background. First thickened ray of dorsal, pectoral, pelvic, and anal fins and external rays of caudal fin with chromatophores arranged in three or four discernible blotches. Branched rays in these fins with similar color pattern. Caudal fin mostly primarily dark brown, with three or four light irregular vertical bands.

Distribution and habitat. Eurycheilichthys luisae is known from several localities in both the upper and lower courses of the rivers Forqueta, Carreiro, Turvo, and the rio das Antas - all tributaries to the rio Taquari, Rio Grande do Sul, Brazil ( Fig. 11). All localities are creeks or rivers with medium to fast flowing water and substrate covered with rocks and stones. Fish are commonly found among the loose stones on the substrate.

Etymology. Eurycheilichthys luisae is named in honor of my daughter Luisa F. Reis, who loves nature and occasionally assisted on weekend field trips for collecting specimens. A

noun in the genitive case.

Conservation status. Eurycheilichthys luisae is frequent and abundant in the upper rio Taquari basin. Despite the Extent of Occurrence (EOO) is approximately 7,700 km 2 and hydroelectric dams exist and are planned in that basin, no specific threats were detected, and the species can be categorized as Least Concern (LC) according to IUCN criteria (IUCN, 2016).