Pyrrhulina marilynae, Netto-Ferreira, André L. & Marinho, Manoela M. F., 2013

Netto-Ferreira, André L. & Marinho, Manoela M. F., 2013, New species of Pyrrhulina (Ostariophysi: Characiformes: Lebiasinidae) from the Brazilian Shield, with comments on a putative monophyletic group of species in the genus, Zootaxa 3664 (3), pp. 369-376 : 370-374

Pyrrhulina marilynae , new species

Figure 1 , Table 1

Holotype. MCP 47420 (ex-MCP 30227), 30.0 mm SL. Brazil, Mato Grosso, Tapurah, stream crossing MT-338 road, 62 Km to the north of Tapurah, 12°15'29”S 56°38'59”W, 19 Jan 2002, R. E. Reis, L. R. Malabarba and E. H. Pereira;

Paratypes. (94 specimens). All from Brazil, Mato Grosso: MCP 30227 (14, 14.2–30.4 mm SL), collected with the holotype; ANSP 199222 (2, 26.3–26.7 mm SL), MCP 30231 (22, 23.1-28.8 mm SL), MNRJ 40361 (2, 24.1– 25.3 mm SL), MZUSP 112227 (2, 26.9–28.0 mm SL), UF 184704 (2, 24.35–27.2 mm SL), Tabaporã, stream crossing MT-220, about 170 Km east from Porto dos Gaúchos, rio Teles Pires drainage, 11°36'48.0"S 55°57'4.0"W, 20 Jan 2002, R. E. Reis, L. R. Malabarba and E. H. Pereira; MNRJ 23298 (3, 18.1–23.6 mm SL), Porto dos Gaúchos, córrego Ortigueira tributary of Rio Braço Dois (Rio dos Peixes), on road Tapurah–Porto dos Gaúchos, 19 Jan 2002, P. A. Buckup, A. T. Aranda, F. Silva, C. A. A. Figueiredo; MZUSP 55305 (8, 22.3–34.3 mm SL), Claudia, 10-25 Mar 1997, M. Rodrigues, G. Skuk, D. Pavan, V. X. Silva; MZUSP 61130 (23, 16.9–26.3 mm SL; 2 cs, 24.7–30.7 mm SL), Nova Mutum, headspring flowing into Rio Criquirin (tributary of Rio dos Patos), 19 Feb 2000, graduate students of the MZUSP; MZUSP 93557 (4, 23.8–27.8 mm SL), stream at Sacocal farm, flowing into Rio Papagaio, near the road to Brasnorte, 12°47'1.86”S 58°23'29”W, 9 oct 2006, F. A. Machado and F. C. T. Lima; USNM 199170 (6, 25.8–31.5 mm SL), upper rio Juruena, H. Schultz, 8 Jun 1962. USNM 268230 (4, 23.9– 34.1 mm SL), Porto dos Gaúchos, rainforest stream at rio Arinos, 20 Aug 1984, M. Goulding et al.

Diagnosis. Pyrrhulina marilynae differs from all congeners (except Pyrrhulina zigzag ) by presenting a conspicuous, dark primary stripe extending from tip of snout to middle caudal-fin rays, with a zigzag pattern along most body length (vs. primary stripe straight and narrow, mostly restricted to the head or not extending posterior to vertical through anal fin origin). Pyrrhulina marilynae differs from P. zigzag by the presence of a distinct, clear zigzag area lying between the primary stripe and the strongly pigmented dorsum; the lack of a hiatus on the primary stripe; and the absence of elongate dorsal-, anal- and caudal-fin rays in males (vs. clear zigzag area absent, and dorsum poorly pigmented; presence of a hiatus on the primary stripe at approximately fifth scale of fourth longitudinal series; rays of dorsal, anal and caudal-fin upper lobe distinctly elongate in males; Fig. 2 ). The new species further differs from all congeners (except P. australis ) by presenting nine principal rays on caudal-fin dorsal lobe, and 18 or less precaudal vertebrae (vs. 10 principal rays on caudal-fin dorsal lobe and 19 or more precaudal vertebrae). It can be further distinguished from P. australis by the absence of the posthcleithrum 2 (vs. postcleithrum 2 present).

Description. Morphometric data of the holotype and paratypes are presented in Table 1 . Lateral view of male holotype and female paratype in Fig. 1 (a and b, respectively). Body cylindrical, elongate. Greatest body depth located anterior to dorsal-fin origin between pectoral and pelvic fins. Dorsal profile of head convex from tip of upper lip to vertical through anterior nostril, slightly concave or nearly straight from that point to scaled portion of parietals, slightly concave from latter point to dorsal-fin origin and distinctly concave from that point to dorsal fin terminus; slightly concave or nearly straight from that point to anteriormost dorsal caudal-fin procurrent ray. Ventral profile of head and trunk distinctly convex from tip of lower lip to anal-fin terminus, and slightly concave from that point to origin of anteriormost ventral caudal-fin procurrent ray.

Mouth superior. Premaxillary with two series of pedunculate conical teeth; outer series with 11(2) or 12(2); inner with 17(1) or 18(1) in females and 21(1) or 23(1) in males. Maxillary with 2(1) or 3(1) conical teeth in females and 8(1) or 11(1) in males, anteriormost tooth usually largest. Posterior terminus of maxilla slightly beyond anterior margin of orbit. Dentary with two series of conical teeth; outer with 11(1) or 12(1) in females and 14(1) or 15 (1) in males, decreasing gradually in size posteriorly; inner with 20(1) or 22(1) in females and 32(2) in males, minute conical teeth, extending from symphysis to coronoid process. Branchiostegal rays 3(2); three articulating with the anterior ceratohyal and one with the posterior.

Scales cycloid, circuli restricted to border of scales, several radii converging to center of scale and strongly anastomosed at focus but not forming cells. Lateral line series with 21(8), 22*(6), 23(2) or 24(1) scales, none perforated despite of canal present at medial portion of anteriormost 1-4 scales. Longitudinal rows of scales between dorsal and pelvic fin 5*(20). Predorsal scales 11(1), 12(10) or 13*(9). First longitudinal scale row with 9(1), 10(8), 11(4) or 12*(6) scales, extending approximately between vertical through pelvic- and dorsal-fin origins. Circumpeduncular scales 10*(20).

Pectoral-fin rays i,11(7) or i,12*(13). Tip of longest pectoral-fin ray falling far short of vertical through pelvicfin insertion. Pelvic-fin rays i,6(1) or i,7*(19). Tip of longest pelvic-fin ray not reaching anal-fin origin. Supraneurals 7, located anterior to neural spine of centra 7 to 13(2). Dorsal-fin rays ii,8*(20). First dorsal-fin pterygiophore inserting anterior to neural spine of centrum 14(2). Distal margin of extended dorsal fin rounded.

Dorsal-fin origin located distinctly closer to caudal-fin origin than to tip of snout. Base of last dorsal-fin ray situated distinctly anterior to vertical through anal-fin origin. Anal-fin rays iii,8*(20), with last ray adnate. Profile of extended anal fin rounded. First anal-fin pterygiophore inserted posterior to haemal arch of centrum 18(2). Adipose fin absent. Caudal fin furcated with upper lobe slightly longer than lower lobe; both lobes rounded. Principal caudal-fin rays i, 8/i,8*(7), ii, 6/i,8(1) or ii, 7/i,8(12). Dorsal caudal-fin procurrent rays 4(2); ventral caudalfin procurrent rays 4(2). Precaudal vertebrae 17(2); caudal vertebrae 16(2).

Color in alcohol. Background color yellowish. Light brown pigmentation onto dorsal portion of head from upper lip to first scales overlying portion of parietal; similar pigmentation pattern extending from that point to caudal-fin origin, along mid-dorsal series of scales and longitudinal scale series one and two. Maxilla, infraorbitals 1 and 5 and opercle strongly pigmented where primary stripe runs through, becoming distinctly lighter ventrally; infraorbitals 2-4 and remaining opercular series bones lightly colored, with scattered chromatophores. Lower lip densely pigmented. Ventral portion of head with scarce pigmentation. Opercular membrane mostly hyaline with small scattered chromatophores, but densely pigmented where primary stripe passes.

Trunk dark dorsally, becoming lighter at second longitudinal series of scales. Scales of third longitudinal series with mid-dorsal margins pigmented similarly to scales of second series, forming light zigzag band between dark dorsum and primary stripe. Primary stripe on body formed by overlaid dark pigmentation of mid-ventral margins of scales of third longitudinal series and mid-dorsal margin of scales of fourth longitudinal series, forming a dark zigzag band between pectoral girdle and vertical through anal-fin median portion; stripe nearly straight from that point to distal end of caudal-fin median rays. Abdominal region yellowish, with minute dark chromatophores from isthmus to anal-fin origin. Humeral blotch absent. Pectoral, pelvic and anal fins mostly hyaline with distal border densely pigmented; caudal fin mostly hyaline, except for median rays, onto which the primary stripe extends. Dorsal fin with round blotch onto mid-distal portion of last unbranched and first branched rays, extending towards base of posterior dorsal-fin rays.

Sexual dimorphism. Adult males of Pyrrhulina marilynae present the general lebiasinid pattern of sexual dimorphism in which male specimens present the anal-fin rays and intervening membrane distinctly thicker than females, and hypertrophied anterodorsally directed process in the first lepidotrichia, where erector muscles attach (Netto-Ferreira et al., 2011). Additionally, the number of maxillary and inner premaxillary teeth differs between males and females of Pyrrhulina marilynae , but further investigation is necessary to confirm whether this is indeed a sexual dimorphism condition of this species, although a similar condition was herein observed in cleared and stained specimens of P. australis and P. v i t t a t a.

Distribution. Pyrrhulina marilynae is known from the headwaters of the rio Tapajós and rio Xingu in the Brazilian Shield ( Fig. 3 ).

Etymology. The specific epithet is in honor to Marilyn Weitzman, for her assistance to both authors since the beginning of their enterprise in studying fishes of the family Lebiasinidae . A noun.

Remarks. Among the species of Pyrrhulina , the new species seems to be closely related to Pyrrhulina australis , P. v i t t a t a and P. z i g z a g, small sized species which rarely grow larger than 30.5 mm SL, contrasting to the other species in the genus, which grow larger than 50.0 mm SL. Species of this putative monophyletic group share a reduction in the number of maxillary teeth, which are restricted to the anterior border of the bone (vs. teeth present along entire anteroventral portion of the maxilla in the remaining species). A less inclusive group comprising Pyrrhulina australis , P. vittata and Pyrrhulina marilynae can also be recognized by having fewer precaudal vertebrae; dorsal-, anal- and caudal-fin rays not elongate in males; foramen through which the nasal nerve runs delimited exclusively by the ethmoidal cartilage and the reduction in size (in P. australis ), or absence (in P. vittata and Pyrrhulina marilynae ) of postcleithrum 2 (vs. 19 or more precaudal vertebrae; dorsal-, anal- and caudal-fin rays distinctly elongate in male; foramen through which the nasal nerve runs delimited by the ethmoidal cartilage and the orbitosphenoid; postcleithrum 2 represented by a relatively large laminar bone). Additionally, the new species shares with P. australis the reduced number of caudal-fin rays on the upper lobe (9 vs. 10 in all remaining Pyrrhulina species).

Although Myers (1926) states that the syntypes of P. rachoviana ( Fig. 4 ) were collected in Rosario, Argentina, there has been considerable questioning regarding the exact locality where type specimens of P. rachoviana have originated in the German literature (Zarske & Géry, 2004; Zarske, 2006). Specimens of that species are considered to have a longitudinal stripe similar to that present in Pyrrhulina marilynae . Nevertheless, both syntypes now lack any coloration on the flanks, although the dorsal and caudal blotches, and those of the primary stripe on the head are still clearly visible. Both species can be distinguished by the caudal-fin color pattern, since in Pyrrhulina marilynae the caudal blotch is minute, distinctly rounded, overlapped by the primary stripe, which extends to the medio-distal portion of median caudal-fin rays, whereas that of P. rachoviana is vertically elongate, with a second crescent shaped blotch, with no trace of the primary stripe onto the caudal fin. The color pattern on the caudal fin of P. rachoviana is also observed in specimens of Pyrrhulina occurring in the rio Tietê, upper rio Paraguay and the Amazon system, and is depicted in Zarske and Géry (2004: Fig. 12). Additionally, the syntypes of P. rachoviana present a more robust body, instead of the slender body observed in P. australis and Pyrrhulina marilynae . Given these differences between the three nominal species of Pyrrhulina , the synonymy of P. rachoviana with P. australis proposed by Zarske and Géry (2004) may have been precipitated.

Comparative material. Pyrrhulina australis CAS 60490, holotype, (36.6 mm SL); P. beni CAS 60493, syntypes, (2, 36.2-36.4 mm SL); P. b re v i s NMW 76177.2, lectotype, (48.8 mm SL); P. eleanorae ANSP 68676, holotype, (39.7 mm SL); P. elongata MHNG 2610.005, paratypes, (3, 27.3-35.5 mm SL); P. filamentosa MNHN 4408, holotype, (53.0 mm SL); MHNLS 23410 (27, 27.4-52.2 mm SL); P. lugubris CAS 78888, holotype, (53.0 mm SL); P. obermülleri CAS 60498, syntypes, (4, 33.2-43.0 mm SL); P. rachoviana USNM 92970, syntypes, (2, 30.6-32.9 mm SL); P. semifasciata NMW 56975, syntypes, (3, 31.1-33.1 mm SL); P. s to l i BMNH 1911.10.31.133- 137 (5, 31.2-70.8 mm SL); P. v it ta ta BMNH1912.8.31.2, holotype, (21.8 mm SL); P. zigzag MTD F 17705 , holotype, (34.5 mm SL); INHS 56206 (5, 26.2-30.9 mm SL).

Figures

FIGURE 1. Pyrrhulina marilynae, new species: (a) MCP 47420 holotype, male, 30 mm SL, Mato Grosso, Tapurah, stream crossing MT- 338 road, 62 Km to the north of Tapurah, 12 ° 15 ' 29 ” S 56 ° 38 ' 59 ” W; and (b) MCP 30231 paratype, female, 27.2 mm SL, Mato Grosso, Tabaporã, stream crossing MT- 220, about 170 Km east from Porto dos Gaúchos, rio Teles Pires drainage, 11 ° 36 ' 48.0 " S 55 ° 57 ' 4.0 " W ".

FIGURE 2. Pyrrhulina zigzag INHS 56206: (a) male 30.9 mm SL; and (b) female 26.2 mm SL. Both from Peru, Lotero, Ulipa, near Iquitos, 03 ° 47.613 ' S, 73 ° 13.726 ' W.

FIGURE 3. Map of northern portion of South America with the collecting sites and type-locality (open circle) of Pyrrhulina marilynae, new species.

FIGURE 4. Syntypes of Pyrrhulina rachoviana USNM 92970: (a) male, 30.6 mm SL; (b) female, - 32.9 mm SL. Both from “ Rosario ”.

Tables

TABLE 1. Morphometric data for Pyrrhulina marilynae, new species. SD = standard deviation.

	Holotype	n	Range Mean	SD
Standard Length	30.0	20	23.8 – 30.4 27.6	1.9
Percentage of SL
Depth at dorsal-fin origin	27.1	20	21.0 – 27.1 24.4	1.4
Snout to anal-fin origin	73.1	20	68.6 – 77.0 72.9	2.1
Snout to pelvic-fin origin	51.6	20	46.4 – 54.1 50..3	1.9
Snout to dorsal-fin origin	62..8	20	58.3 – 63.6 60.7	1.5
Dorsal-fin origin to caudal base	39.3	20	37.6 – 43.5 40.2	1.3
Dorsal-fin length	25.3	20	22.2 – 28.2 25.0	1.6
Length of caudal peduncle	16.1	20	14.7 – 19.5 16.8	1.3
Depth of caudal peduncle	14.0	20	11.2 – 14.2 12.6	0.8
Anal-fin length	25.1	20	19.5 – 25.8 22.7	1.6
Anal-fin base length	14.5	20	10.5 – 14.5 12.3	0.8
Pelvic- to anal-fin origin	21.8	20	20.6 – 25.9 24.1	1.3
Pelvic-fin length	22.1	20	17.6 – 23.9 20.1	1.8
Pectoral- to pelvic-fin origin	27.3	20	23.6 – 29.9 26..1	1.3
Pectoral-fin length	21.5	20	18.1 – 24.0 21.3	1.6
Snout to pectoral-fin origin	26.7	20	24.3 – 28.5 26.5	1.0
Head length	27.0	20	25.3 – 28.9 26.7	0.9
Percentage of HL			–
Horizontal eye diameter	35.6	20	33.8 – 39.3 36.9	1.6
Distance of tip of snout to eye	27.4	20	24.8 – 30.1 27.3	1.5
Interorbital distance	42.1	20	37.5 – 43.9 40.5	1.8
Upper jaw lenght	34.1	20	30.0 – 41.5 34.5	3.0
Lower jaw lenght	41.1	20	33.7 – 44.2 39.5	2.5