Pareiorhaphis lineata, Pereira & Pessali & Andrade & Reis, 2017

Pereira, Edson H. L., Pessali, Tiago C., Andrade, Francisco de & Reis, Roberto E., 2017, Description of a new species of Pareiorhaphis (Loricariidae: Neoplecostominae) from the rio Jequitinhonha basin, Minas Gerais, eastern Brazil, Neotropical Ichthyology 15 (3), No. e 170007, pp. 1-10 : 2-7

Pareiorhaphis lineata , new species

urn:lsid:zoobank.org:act:41768249-5E1B-44AA-AECA-AD68E44EBEE7

Fig. 1, Tab. 1

Holotype. MCP 50863, 95.1 mm SL, male, Brazil, Minas Gerais State, Grão Mogol, rio Jequitinhonha basin, rio Itacambiruçu , 16°35’51.6”S 42°50’15.4”W, 23 Nov 2010, F. Andrade & W. A. Santos.

Paratypes. Brazil: Minas Gerais State: rio Jequitinhonha drainage: AMNH 266888 , 3 , 63.1-72.3 mm SL; AUM 67843, 3 , 65.6-73.4 mm SL; MCP 50880, 27 , 25.1-64.1 mm SL, Josenópolis, ribeirão Piabanha , left margin tributary to rio Jequitinhonha , 16°32’46.08”S 42°31’42.18”W, 13 Apr 2015, T. C. Pessali, G. M. Santos & I. S. Penido. MCNIP 1494 , 2 , 68.1-74.6 mm SL (1, 74.6 mm SL), Grão Mogol, rio Itacambiruçu , 16°35’16.37”S 42°48’53.19”W, 6 Apr 2013, T. C. Pessali, M. L. Pugedo, A. A. Rodrigues & G. N . Salvador. MCNIP 1495 (1, 74.0 mm SL), Grão Mogol, rio Itacambiruçu , 16°35’12.45”S 42°51’15.82”W, 10 Apr 2013, T. C. Pessali, M. L. Pugedo, A. A. Rodrigues & G. N . Salvador. MCNIP 1499 , 7 , 30.8-71.7 mm SL (2, 68.8-71.7 mm SL), Cristália, rio Itacambiruçu at Praia do Vau , 16°35’25.89”S 42°53’23.98”W, 19 Sep 2012, T. C. Pessali & G. C. G. Mello. MCNIP 1701 (2, 87.0- 93.2 mm SL), Itaobim , ribeirão São João , 16°39’30.29”S 41°30’04.91”W, 12 Sep 2015, T. C. Pessali, T. A. Barroso & S. G. Máximo. MCNIP 1703 , 8 , 34.3-84.4 mm SL (1, 84.4 mm SL), Grão Mogol , rio Itacambiruçu , 16°35’16.37”S 42°48’53.19”W, 29 Dec 2014, T. C. Pessali, J. C. de Oliveira & I. S. Penido. MCNIP 1708 , 8 , 50.0- 87.8 mm SL, Grão Mogol , rio Itacambiruçu , 16°35’12.45”S 42°51’15.82”W, 15 Sep 2014, T. C. Pessali, A. A. Rodrigues & D. F. Teixeira. MCNIP 1729 , 18 , 39.1 -82.0 mm SL (3, 79.4-82.0 mm SL), Ponto dos Volantes, ribeirão São Joanico , left margin tributary to ribeirão São João , 16°52’52.81”S 41°29’22.42”W, 17 Apr 2015, T. C. Pessali, G. M. Santos & I. S. Penido. MCNIP 1725 , 2 , 72.9-115.7 mm SL (1, 115.7 mm SL), Ponto dos Volantes, ribeirão São João , right margin tributary to rio Jequitinhonha , 16°58’47.91”S 41°26’51.20”W, 17 Apr 2015, T. C. Pessali, G. M. Santos & I. S. Penido. MCP 50862, 2 , 88.9-91.9 mm SL (1, 91.9 mm SL), Grão Mogol, rio Itacambiruçu , 16°35’51.06”S 42°50’15.04”W, 19 May 2010, F. Andrade & W. A. Santos. MCP 50876, 9 , 58.3 -90.0 mm SL (7, 58.3-90.0 mm SL), Grão Mogol, rio Itacambiruçu , 16°35’12”S 42°51’15”W, 30 Dec 2011, T. C. Pessali & A. A. Rodrigues. MCP 50879 (2, 87.5- 96.9 mm SL), Cristália, rio Itacambiruçu , 16°36’23.96”S 42°49’46.83”W, 10 Feb 2014, T. C. Pessali, N. G. Sales & G. M. Santos. MCP 50881, 6 , 41.9-95.7 mm SL (3, 66.4-95.7 mm SL), Grão Mogol, rio Itacambiruçu , 16°35’12.45”S 42°51’15.82”W, 16 Sep 2012, T. C. Pessali & G. C. G. Mello. MCP 50882, 9 , 38.7-94.6 mm SL (2, 75.3-94.6 mm SL), Grão Mogol, rio Itacambiruçu , 16°35’12.45”S 42°51’15.82”W, 27 Dec 2014, T. C. Pessali, J. C. de Oliveira & I. S. Penido. MCP 44927, 5 , 40.5-84.3 mm SL (2, 71.6-84.3 mm SL); MNRJ 48689 , 3 , 66.5-73.5 mm SL (2, 66.5-73.5 mm SL), Leme do Prado , ribeirão Correntes at Mandaçaia, 16°59’47”S 42°44’43”W, 21 Jan 2010, R. E. Reis, P. Lehmann & E. H. L. Pereira. MZUEL 17319 , 2 , 71.7-87.9 mm SL; and MCP 50971, 6 , 60.9-98.4 mm SL + 2 c&s, 78.5-88.0 mm SL, Grão Mogol, rio Itacambiruçu , 16°35’51.4”S 42°50’15.4”W, 4 Jun 2011, F. Andrade, L. Durães, A. Santos & H. J. Alves .

Non-types. Brazil: Minas Gerais State: rio Jequitinhonha basin : ANSP 174076 , 5 , 50.4-67.8 mm SL ; MCP 18039, 3 , 22.4-72.8 mm SL + 1 c&s 63.9 mm SL, Padre Paraíso, rio São João on road BR-116 between Padre Paraíso and Itaobim, ca. 119 km of Teófilo Otoni , 16°56’06”S 41°27’46”W, 20 Jan 1995 , R. E. Reis, W. G. Saul, J. F. P. da Silva & E. H. L. Pereira . MCNIP 0005 , 4 , 25.5-62.2 mm SL, Grão Mogol, rio Itacambiruçu , 16°34’52”S 42°52’25”W, Sep 2011 , T. C. Pessali & G . R. Rosa . MCNIP 0009 , 2 , 50.2-63.5 mm SL, Grão Mogol, rio Itacambiruçu , 16°35’16”S 42°48’53”W, Sep 2011 , T. C. Pessali & G . R. Rosa . MCNIP 1496 , 6 , 53.9- 65.3 mm SL, Grão Mogol, rio Itacambiruçu , 16°35’12.45”S 42°51’15.82”W, 2 Nov 2013 , T. C. Pessali & T. A. Barroso . MCNIP 1498 , 4 , 40.9-68.3 mm SL, Grão Mogol, rio Itacambiruçu , 16°34’52.79”S 42°52’25.73”W, 17 Sep 2012 , T. C. Pessali & G. C. G. Mello . MCNIP 1712 , 13 , 36.9- 63.5 mm SL, Grão Mogol, rio Itacambiruçu , 16°35’16.37”S 42°48’53.19”W, 16 Sep 2014 , T. C. Pessali, A. A. Rodrigues & D. F. Teixeira . MCNIP 1713 , 3 , 47.4-56.8 mm SL, Grão Mogol, rio Itacambiruçu at Praia do Vau , 16°35’25.89”S 42°53’23.98”W, 18 Sep 2014 , T. C. Pessali, A. A. Rodrigues & D. F. Teixeira . MCNIP 1697 , 1 , 73.9 mm SL, Grão Mogol, rio Itacambiruçu , 16°35’50.35”S 42°50’22.39”W, 31 Dec 2014 , T. C. Pessali, J. C. de Oliveira & I. S. Penido . MCNIP 1719 , 3 , 35.9-44.1 mm SL, Grão Mogol, rio Itacambiruçu , 16°35’58.02”S 42°55’37.42”W, 27 Jul 2013 , T. C. Pessali, M. L. Pugedo & I. S. Penido . MCNIP 1721 , 7 , 40.1-72.8 mm SL, Grão Mogol, rio Itacambiruçu , 16°35’12.45”S 42°51’15.82”W, 10 Apr 2015 , T. C. Pessali, G. M. Santos & I. S. Penido . MCNIP 1722 , 5 , 38.2-45.1 mm SL, Grão Mogol, rio Itacambiruçu , 16°35’16.37”S 42°48’53.19”W, 11 Apr 2015 , T. C. Pessali, G. M. Santos & I. S. Penido . MCNIP 1724 , 5 , 34.0- 58.7 mm SL, Grão Mogol, rio Itacambiruçu , 16°34’52.79”S 42°52’25.73”W, 23 Jul 2013 , T. C. Pessali, M. L. Pugedo & I. S. Penido . MCNIP 1711 , 17 , 36.3-77.2 mm SL, Grão Mogol, rio Itacambiruçu , 16°34’52.79”S 42°52’25.73”W, 14 Sep 2014 , T. C. Pessali, A. A. Rodrigues & D. F. Teixeira . MCP 36916, 9 , 24.6 -78.0 mm SL + 1 c&s 65.9 mm SL (3, 64.6-78.0 mm SL), Itaobim, rio São João on road BR-116 between Padre Paraíso and Itaobim , ca. 119 km N of Padre Paraíso, 16°56’06”S 41°27’46”W, 10 Oct 2004 , R. E. Reis, P. Lehmann & E. H. L. Pereira . MCP 49292, 16 , 34.4-74.6 mm SL, Itamarandiba, headwaters of rio Itacambira Grande on road from Itacambira to Senador Modestino Gonçalves , ca. 14 km of Itamarandiba , 17°53’23”S 42°59’57”W, 27 Jul 2015 , R. E. Reis, P. Lehmann & E. H. L. Pereira . MCP 49362, 20 , 21.3-52.3 mm SL, Itamarandiba, rio Itanguá, tributary to rio Araçuaí on road from Itamarandiba to Senador Modestino Gonçalves , ca. 30 km of Itamarandiba , 17°54’38”S 43°07’07”W, 27 Jul 2015 , R. E. Reis, E. H. L. Pereira & P. Lehmann . MCNIP 1716 , 3 , 40.1-51.7 mm SL, Bocaiúva, rio Macaúbas, left margin tributary to rio Jequitinhonha , 17°13’13.49”S 43°29’21.43”W, 6 Apr 2015 , T. C. Pessali, G. M. Santos & I. S. Penido . MCNIP 1714 , 1 , 53.9 mm SL, Olhos D’Água , ribeirão dos Ferreira, right margin tributary to ribeirão da Areia, 17°26’09.57”S 43°37’02.25”W, 20 Sep 2014 , T. C. Pessali, A. A. Rodrigues & D. F. Teixeira . MCNIP 1723 , 1 , 54.8 mm SL, Josenópolis, córrego Curralinho, tributary to ribeirão Piabanha , itself a left margin tributary to rio Jequitinhonha , 16°30’56.73”S 42°32’54.82”W, 13 Apr 2015 , T. C. Pessali, G. M. Santos & I. S. Penido . MCP 50861, 1 , 59.5 mm SL, Padre Carvalho, rio Vacaria , 16°22’54.07”S 42°28’37.00”W, 1 Sep 2010 , F. Andrade & W. A. Santos. MCP 50877, 2 , 72.8-73.1 mm SL, Grão Mogol, rio Itacambiruçu , 16°35’51”S 42°50’06”W, Nov 2011 , F. R. A. Neto, L. D. S. Durães & T. C. Pessali . MCP 50878, 1 , 70.6 mm SL, Ponto dos Volantes, ribeirão São João , 16°45’38.30”S 41°29’29.63”W, 11 Sep 2015 , T. C. Pessali , T. A. Barroso & S. G. Máximo . MZUEL 12160 , 8 , 39.3-72.4 mm SL, Setubinha, creek tributary to rio Araçuaí , 17°40’05”S 42°10’03”W, 28 Jun 2014 , F. Andrade, T. Barroso & I. G. Prado .

Diagnosis. Pareiorhaphis lineata can be diagnosed from all congeners by a putative autapomorphy, the possession of a dark brown stripe on the median series of lateral plates that extends along the flank from the posterior margin of compound pterotic to the caudal-fin base (vs. no dark stripe on flank). In addition, P. lineata can be distinguished from all other congeners, except P. stephanus , by having the entire margin of the head ornamented with hypertrophied odontodes in adult males (vs. hypertrophied odontodes on the cheeks only). From the remaining species, except P. garbei and P. stephanus , it is distinguished by a longer dorsal fin, whose posterior margin reaches the middle or distinctly beyond the middle of the anal fin when adpressed in adult males (vs. a short dorsal fin, whose posterior margin does not reach to or slightly surpasses the anal-fin origin). The shallower caudal peduncle (7.9-9.0 vs. 9.1-14.0% SL) also distinguishes P. lineata from P. azygolechis , P. bahianus , P. cameroni , P. cerosus , P. eurycephalus , P. garapia , P. hypselurus , P. lophia , P. mutuca , P. nudulus , P. regani , and P. stomias . The larger number of dentary teeth (66-105 vs. 30-62) distinguishes Pareiorhaphis lineata from P. hystrix , P. parmula , P. steindachneri and P. vestigipinnis . The new species is further distinguished from P. garbei and P. stephanus by the pectoral-fin spine, which is ornamented with hypertrophied odontodes shorter than one orbital diameter in adult males (vs. larger hypertrophied odontodes longer than one orbital diameter). The new species is further diagnosed from P. stephanus by having the greatest body width at posterior portion of cheek (vs. greatest body width at cleithrum) and, especially juveniles and females, by the smaller eye diameter (12.7-16.2% HL) vs. larger eye diameter (18.1-20.1% HL); and longer snout (60.8-66.5% HL) vs. shorter snout (55.5-60.8% HL).

Description. Counts and proportional measurements in Tab. 1. Overall view of body in Fig. 1. Small to mediumsized loricariid with standard length of measured specimens 58.3-115.7 mm SL. Body elongate and dorsoventrally flattened. Greatest body width at posterior portion of cheek, progressively tapering to end of caudal peduncle. Dorsal profile of body gently convex from snout tip to dorsal-fin origin and almost straight from that point to end of adipose fin, then slightly concave to caudal fin. Greatest body depth immediately anterior to dorsal-fin origin. Least body depth at shallowest part of caudal peduncle. Trunk horizontally oval in cross-section, flattened ventrally; caudal peduncle strongly flattened ventrally and markedly compressed caudally. Lateral-line canal in median plate series uninterrupted, with pored tube from compound pterotic to penultimate plate before caudal fin.Ventral profile almost straight between snout tip and pelvic girdle, then slightly ascending to caudal-fin origin. Dorsolateral surface of body covered by plates except for narrow naked area around dorsal-fin base and opening of swimbladder capsule, posteroventrally to compound pterotic. Predorsal plates arranged in two or three pairs of plates in some specimens, sometimes randomly distributed. Five rows of lateral dermal plates covering body, not forming keels except for ventral series of adult males. Mid-dorsal and midventral series of lateral plates incomplete, ending 5-7 plates before caudal-fin base. Ventral surface of head, abdomen, and region around urogenital opening naked.

Head broad and moderately depressed, rounded in dorsal view; widened in adult males. Interorbital space flat to slightly concave. Three weak elevations between orbits and snout tip; one median from snout tip to area between nostrils and two in front of orbits. Elevations ornamented with many short hypertrophied odontodes directed upward in adult males. Snout tip with small ovoid area of naked skin; covered by short hypertrophied odontodes in fully developed adult males. Adult males with well-developed soft fleshy lobes extending along lateral and sometimes anterior portions of head. Eye small, dorsolaterally placed; iris operculum small or unnoticeable. Nares ovoid, slightly longer than wide, positioned much closer to anterior margin of orbit than to snout tip. Narrow area of naked skin in front of nostril, between mesial margin of infraorbitals 1 and 2 and prenasal plates. Oral disk oval; lips well developed, occupying most of ventral surface of head. Lower lip wide and long, not reaching pectoral girdle, upper lip narrow. Lower lip densely covered by minute papillae. Papillae surrounded by small naked areas, decreasing in size towards edge and absent near lip margin. Margin of lower lip slightly fringed. Maxillary barbel short, mostly adnate to lower lip and with small free portion distally. Teeth series in both premaxilla and dentary forming shallow arc with overall angle of approximately 130-140 degrees, with mesial ends slightly curved inwards. Teeth slender, asymmetrically bifid, medial cusp slightly curved inwards. Lateral cusp small and pointed, never reaching half-length of medial cusp in unworn teeth.

Dorsal-fin posterior margin straight to slightly concave; usually not contacting preadipose azygous plates when adpressed, sometimes contacting first preadipose plates in adult males. Nuchal plate exposed, not covered by skin. Dorsal-fin spinelet oval-shaped, varying from slightly wider than base to usually narrower than base of dorsal-fin spine, sometimes divided into two small platelets, or absent. Dorsal-fin locking mechanism non-functional. Dorsal-fin spine moderately flexible, followed by seven branched rays. Adipose fin with well-ossified leading spine bearing odontodes. Adipose-fin membrane short or extended slightly beyond adipose-fin spine. Adipose fin preceded by 1-5 (usually 2-3) median preadipose azygous plates. Pectoral-fin origin situated slightly dorsal to pelvic-fin origin. Pectoral fin moderate in size, with spine slightly curved and flattened, covered by minute odontodes in females, immature males, and juveniles. Adult males with pectoral-fin spine very broad, bearing straight and short hypertrophied odontodes over entire outer surface. Pectoral fin with six branched rays, first and second longer than spine. Subsequent branched rays decrease gradually in size, last ray half length of first one. Distal margin of pectoral fin approximately straight. Tip of adpressed pectoral fin almost reaching or reaching to mid-length of pelvic-fin unbranched ray. Pelvic fin with one unbranched and five branched rays, not reaching or just reaching to origin of anal fin when adpressed. Pelvic-fin unbranched ray depressed, covered with minute odontodes ventrally and laterally. Dermal flap on its dorsal surface present and well developed, extending to ray tip in adult males; absent in females. Anal fin short with one unbranched and five branched rays; passing vertical at adiposefin origin when adpressed. Caudal fin with 14 branched rays, posterior margin slightly forked; ventral lobe distinctly longer than dorsal (24.1-31.8 vs.19.5-23.5% SL). Dorsal caudal-fin lobe with 4-5 and ventral lobe with 3-5 plate-like procurrent rays, posteriormost elongate. Odontodes on principal and procurrent rays small and irregularly arranged. Hypural plate asymmetrical with ventral lobe longer than dorsal. Total vertebral centra 29.

Color in alcohol. Overall background color of dorsal and lateral surface of head and trunk pale yellow to light brown, sometimes brownish gray. Flank with conspicuous dark brown stripe from compound pterotic to caudal fin on median series of lateral plates, distinctly contrasting with lighter color of mid-ventral and ventral series of plates ( Fig. 1). Scattered dark blotches and dark saddles common to other species, absent in P. lineata . Ventral surface of head and abdomen yellowish or whitish pale or with small dark grey spots scattered on lateral portion of abdomen and caudal peduncle. Dorsal fin with 3-4 inconspicuous dark blotches on spine and branched rays; interradial membrane darkened. Paired fins darkened anteriorly and pale yellow posteriorly. Caudal fin with rays and interradial membrane gray.

Color in life. Similar to color in alcohol but contrast between dark brown longitudinal stripe and lighter mid-ventral and ventral series of plates more conspicuous. Lateral portion of snout between eye and fleshy lobe on cheek darkened. Distal margin of caudal fin chestnut brown ( Fig. 2).

Sexual dimorphism. Pareiorhaphis lineata shares with all members of the genus the remarkable morphological modifications already known to occur in adult males of Pareiorhaphis . Some of those attributes in the new species are especially developed, as the fleshy lobes that extend along the entire margin of the head and that are ornamented with short emerging hypertrophied odontodes, both of which are absent in females; by a thickened pectoral-fin spine strongly intumescent along its entire length with dorsal, lateral, and ventral surfaces ornamented with short hypertrophied odontodes, sometimes equal in size to those on head margin, that are absent in females; and by the skin fold on the dorsal surface of the unbranched pelvic-fin ray that extends to the ray tip and is slightly higher near the fin base, whereas the skin fold is absent or very reduced in females. Other examples of secondary sexual dimorphism of adult males include distinct keels of the ventral series of lateral plates; three weak elevations between the orbits and the snout tip that are covered with many short hypertrophied odontodes directed upward; dorsal-fin posterior margin that sometimes contacts the first preadipose plate; and possession of a much broader head than females. Compared to males, females possess an enlarged, swollen urogenital opening, while males have small and pointed urogenital papillae.

Geographical distribution. Upper and middle rio Jequitinhonha basin in the state of Minas Gerais, Brazil ( Fig. 3).

Ecological notes. Pareiorhaphis lineata was captured in habitats with medium to strong water current and substrate composed of smooth bedrock, large boulders, and cobbles, in addition to small amounts of gravel and sand, usually in low depth (<0.5 m). No individuals were captured in sand bottomed stretches, such as beaches or pools. Rocks were sometimes covered by weeds ( Podostemaceae ). Rivers where specimens were collected are 0.3-4.5 m deep and 1.7-55 m wide, with banks covered by shrub and low trees typical of the Cerrado forest ( Fig. 4). Other loricariids collected syntopically with the new species are Pareiorhaphis stephanus , Delturus brevis , Harttia garavelloi , Chauliocheilos saxatilis , Parotocinclus jequi , Parotocinclus sp. , Hypostomus nigrolineatus , and Hypostomus sp. , further on Astyanax aff. fasciatus , Astyanax cf. pelecus , Hemigrammus marginatus , Knodus moenkhausii , Oligosarcus macrolepis (Characidae) , Characidium spp. (Crenuchidae) , Trichomycterus spp. (Trichomycteridae) , and juveniles of Brycon howesi (Bryconidae) .

Etymology. The species name Pareiorhaphis lineata is from the Latin linea, meaning line or stripe, in reference to the dark stripe on the flank, which is distinctive of this species. An adjective.

Conservation status. Pareiorhaphis lineata is broadly distributed in the upper and middle rio Jequitinhonha basin ( Fig. 3), being relatively frequent and abundant. Its Extent of Occurrence (EOO) was estimated at approximately 24,500 km 2. The lower reach of the rio Itacambiruçu, the second main tributary to the rio Jequitinhonha, has been compromised by the Irapé dam reservoir. Now a series of small dams are planned for the upper and middle reaches of that river, which may substantially reduce suitable habitats for this species. Despite a variety of threats such as contamination by domestic sewage, species introduction (mainly Serrasalmus brandtii from the rio São Francisco), mining, damming, and deforestation, with the subsequent river siltation, were observed in portions of the area of distribution, no specific threats were detected, and Pareiorhaphis lineata should be categorized as Least Concern (LC) according to IUCN criteria (IUCN, 2016).