Moenkhausia chlorophthalma, Sousa & Netto-Ferreira & Birindelli, 2010

Sousa, Leandro M., Netto-Ferreira, André L. & Birindelli, José L. O., 2010, Two new species of Moenkhausia Eigenmann (Characiformes: Characidae) from Serra do Cachimbo, Pará, Northern Brazil, Neotropical Ichthyology 8 (2), pp. 255-264 : 256-262

Moenkhausia chlorophthalma , new species Figs. 1-3

Holotype. MZUSP 99412 (67.4 mm SL), Brazil, Pará, Altamira, rio Treze de Maio, tributary of rio Curuá , rio Iriri basin, rio Xingu drainage, 08º45’06”S 55º02’05”W, 23 Jan 2009, A. L. Netto-Ferreira, J. L. Birindelli, L. M. Sousa & P. Hollanda-Carvalho.

Paratypes. ANSP 188909 (5, 32.9-50.3 mm SL) , AUM 50663 (5, 37.6-43.6 mm SL) , INPA 33764 (5, 34.7-49.4 mm SL) , MCP 44509 (5, 41.0-48.0 mm SL) , MNRJ 35382 (5, 33.8-48.5 mm SL) , MPEG 18327 (5, 37.9-52.9 mm SL) and MZUSP 101426 (81, 23.7-67.9 mm SL), same data as holotype . MZUSP 97092 (28, 38.0- 64.8 mm SL, 2 c&s, 43.3-49.6 mm SL), Brazil, Pará, Altamira, rio Treze de Maio, tributary of rio Curuá , rio Iriri basin, rio Xingu drainage, 08º45’06”S 55º02’05”W, 22 Nov 2007, J. L. Birindelli, L. M. Sousa, A. L. Netto-Ferreira, M. H. Sabaj Pérez & N. K. Lujan .

Diagnosis. Moenkhausia chlorophthalma is distinguished from all congeners, except M. petymbuaba and M. plumbea by the presence of large dark blotches on the anterior to central portions of the scales forming the seven dorsalmost longitudinal series (vs. pigmentation absent or, when present, concentrated posteriorly along the border of the scales, and forming a reticulate pattern on the body). Moenkhausia chlorophthalma can be differentiated from both M. petymbuaba and M. plumbea by the possession of a proximal well-delimited black area on the adipose fin (vs. adipose fin with uniformly scattered dark chromatophores), 7 longitudinal rows of large dark blotches (vs. 8-9), 25-28 lateral line scales (vs. 33-36), 4 scales between the lateral line and the dorsal-fin origin (vs. 5), and 7-12 scales covering the anal-fin base (vs. 4-9). Moenkhausia chlorophthalma can be further separated from M. petymbuaba by lacking a conspicuous midlateral dark stripe (vs. presence of conspicuous midlateral dark stripe); and from M. plumbea by having 7 branched pelvic-fin rays (vs. 6-7 in specimens of M. plumbea examined).

Description. Morphometric data presented in Table 1. Overall size small (largest examined specimen 67.4 mm SL). Body compressed, moderately elongate. Greatest body depth located slightly anterior to dorsal-fin origin. Dorsal profile of head slightly convex from upper lip to vertical through nares; mostly straight from latter point to tip of supraoccipital spine; convex from tip of supraoccipital spine to dorsal-fin origin, straight from near of dorsal fin base to adipose fin; slightly concave between latter and origin of anteriormost dorsal procurrent caudal-fin ray. Ventral profile of head and body distinctly convex from lower lip to anal-fin origin; straight along anal-fin base, and concave between terminus of analfin and anteriormost procurrent caudal-fin ray.

Mouth terminal. Posterior limit of maxilla almost reaching vertical through middle of orbit. Premaxillary teeth in two rows ( Fig. 3 ). Outer row with four (1) or six (1), relatively compressed, tricuspid teeth. Inner row with five (2) bulky tri- to pentacuspid teeth. Symphyseal tooth largest, asymmetrical, with single lateral cusp on anteromedial margin. Maxilla with three equal-sized tricuspid teeth. Dentary with four anteriormost teeth large, robust, pentacuspid, followed by a series of distinctly smaller, conic or tricuspid teeth. First gill arch with 1(2) hypobranchial, 8(2) ceratobranchial, 1(2) on cartilage between ceratobranchial and epibranchial, and 5(1) or 6(1) epibranchial gill-rakers. Branchiostegal rays 4(2), three originating on anterior ceratohyal and one on posterior ceratohyal.

Scales cycloid, with circuli absent on exposed area of scales, and few slightly divergent radii (usually less than 10) extending to posterior margin of scales. Lateral line slightly curved ventrally, completely pored, with 25(7), 26(10), 27*(20) or 28(8) perforated scales. Horizontal scale rows between dorsal-fin origin and lateral line 4(45). Horizontal scale rows between lateral line and pelvic-fin insertion 4(45). Predorsal scales 7(16), 8*(10) or 9(4). Single row of 7(1), 8(1), 9*(5), 10(12), 11(10) or 12(1) scales covering base of anteriormost anal-fin rays. Fourteen circumpeduncular spine of 17 th (2) vertebra. Caudal-fin forked, lobes slightly rounded, similar in size. Principal caudal-fin rays i,9+8,i. Dorsal procurrent caudal-fin rays 13(2) and ventral procurrent caudal-fin rays 9(1) or 11(1). Total vertebrae 34(1) or 35(1), with 16(1) or 17(1) precaudal and 18(2) caudal vertebrae.

Color in alcohol. Ground color tan, with chromatophores densely covering entire body, except for ventral portion. Lower lip, snout, top of head and dorsal portion of body darkly pigmented, resulting in overall countershaded color pattern. Edge of upper lip dark. Inconspicuous humeral blotch present, vertically elongated. Seven dorsalmost longitudinal scale rows with scales bearing large dark blotches anterior to center of each, with blotch fading towards scale border. Longitudinal, broad, dark midlateral stripe slightly curved ventrally, extending from pectoral girdle to tip of middle caudal-fin rays. Stripe diffuse, formed by scattered chromatophores. Dorsal, caudal, anal, and pectoral fins hyaline, with small scattered chromatophores. Adipose fin with proximally well-delimited dark area ( Fig. 1 ).

Color in life. Ground color of dorsal portion of body yellow to greenish, with iridescent midlateral yellow stripe and large, dark, ventrally curved longitudinal stripe immediately ventral to it, stripe extending from humeral region to caudal peduncle. Abdominal region white to light yellow. Eye bright green. Middle caudal-fin rays with dark mark, anteriorly delimited by dorsal and ventral yellowish areas ( Fig. 2 ).

Etymology. From the Greek chloros, meaning green, and ophthalmos, meaning eye, in reference to the iridescent green eyes in live specimens. An adjective.

Distribution. Known from type-locality ( Figs. 4 and 5 ).

Figs. 6-9 central portions of each scale along the seven dorsalmost longitudinal series (vs. pigmentation absent or, when present,

Holotype. MZUSP 99415 (49.5 mm SL), Brazil, Pará, Novo concentrated posteriorly along the border of scales and Progresso, tributary to rio Braço Norte, at bridge of BR 163 road near forming a reticulate pattern in the body). Moenkhausia Air Force Base, rio Peixoto de Azevedo, rio Teles Pires drainage, rio plumbea differs from both M. petymbuaba and M. Tapajós basin; 09º17’59”S 54º50’00”W, 22 Jan 2009; A. L. Netto- chlorophthalma in possessing a dark longitudinal stripe along

Ferreira, J. L. Birindelli, L. M. Sousa & P. Hollanda-Carvalho. the eye; and is further separated from M. petymbuaba in lacking a very conspicuous dark midlateral stripe; and from

Paratypes. All from Brazil, Pará, Novo Progresso. ANSP 188911 (5, 35.1-44.8 mm SL), AUM 50664 (5, 34.3-41.2 mm SL), INPA 33765 M. chlorophthalma in possessing eight or nine longitudinal (5, 35.5-43.7 mm SL), MCP 44510 (5, 32.8-44.2 mm SL), MNRJ rows of large dark blotches (vs. seven), 33-36 lateral line scales 35384 (5, 37.7-46.3 mm SL), MPEG 18328 . (5, 32.3-40.9 mm SL), (vs. 25-28), five scales between lateral line and dorsal fin (vs. MZUSP 96849 (14, 34.0- 51.2 mm SL, 2 c&s, 39.1, 42.0 mm SL), four), 4-9 anal-fin base scales (vs. 7-12), and usually 6 branched tributary of rio Braço Norte, rio Peixoto de Azevedo , rio Teles Pires pelvic-fin rays (vs. 7). basin, rio Tapajós drainage, 09º19’17”S 54º50’26”W, 10 Nov 2007, J. L. Birindelli, L. M. Sousa, A. L. Netto-Ferreira, M. H. Sabaj Pérez & Description. Morphometric data presented in Table 2. Overall N. K. Lujan. MZUSP 101435 (24, 20.4-45.9 mm SL), same locality size small (largest examined specimen 49.7 mm SL). Body as ANSP 188911 , 22 Jan 2009, A. L. Netto-Ferreira, J. L. Birindelli, compressed, moderately elongate. Greatest body depth located

L. M. Sousa & P. Hollanda-Carvalho. MZUSP 101436 (1, 15.6 mm slightly anterior to dorsal-fin origin. Dorsal profile of head slightly

SL), tributary of rio Braço Norte, at bridge of BR 163 road, near the convex from upper lip to vertical through nares; somewhat straight

Air Force Base , rio Peixoto de Azevedo , rio Teles Pires basin, rio Tapajós drainage, 09º21’55”S 54º50’00”W, 22 Jan 2009, A. L. Netto- from latter point to tip of supraoccipital spine; convex from tip of Ferreira, J. L. Birindelli, L. M.Sousa & P.Hollanda-Carvalho. MZUSP supraoccipital spine to dorsal-fin origin, straight from dorsal fin 101439 (10, 30.1-49.3 mm SL), collected with holotype. terminus to adipose fin; slightly concave between latter point and origin of anteriormost dorsal procurrent caudal-fin ray. Ventral

Diagnosis. Moenkhausia plumbea is distinguished from all profile of head and body distinctly convex from lower lip to congeners, except M. chlorophthalma and M. petymbuaba , pelvic-fin origin; straight from latter point to anal-fin origin, and along anal-fin base; concave between terminus of anal-fin and anteriormost procurrent caudal-fin ray.

Mouth terminal.Terminus of maxilla located slightly posterior to vertical through anterior margin of orbit. Premaxillary teeth in two rows ( Fig. 8 ). Outer row with 5(2), relatively compressed, tricuspid teeth. Inner row with 5(2) robust pentacuspid teeth; Symphyseal tooth largest, slightly asymmetrical, with medialmost cusp greatly reduced. Maxilla with two tricuspid equally developed teeth. Dentary with 12(1) or 15(1) teeth; 4 or 5 anteriormost teeth larger, robust, pentacuspid, posterior ones conic, penta- or tricuspid, distinctly smaller. First gill arch with 2(2) hypobranchial, 8(2) ceratobranchial, 1(2) cartilage between ceratobranchial and epibranchial, and 6(2) epibranchial gill-rakers. Branchiostegal rays 4(2). Three rays originating on anterior ceratohyal and one on posterior ceratohyal.

Scales cycloid, circuli absent on exposed portion of scales, with few (usually up to 15) slightly divergent radii extending to posterior margin of scales. Lateral line slightly pterygiophore inserted posterior to neural spine of 10 th vertebra (2). Adipose fin present. Anal-fin rays iii, 20(1); iv, 18(6); iv, 19(3); iv, 20(17); iv, 21(10); iv, 22*(2); v, 19(1) or v, 20(4). Anteriormost anal-fin pterygiophore inserted behind haemal spine of 17 th vertebra (2). Caudal fin forked, lobes slightly rounded and similar in size. Principal caudal-fin rays 10+9. Ten (2) dorsal procurrent and nine (2) ventral procurrent caudal-fin rays. Total vertebrae 35(1) or 36(1) with 17(2) precaudal and 18(1) or 19(1) caudal vertebrae.

curved ventrally, completely pored, with 33(3), 34*(8), 35(11), 36(7) or 37(1) perforated scales. Horizontal scale rows between dorsal-fin origin and lateral line 5. Horizontal scale rows between lateral line and pelvic-fin insertion 4. Predorsal scales 9(5), 10*(24) or 11(1). Single row of 5*(7), 6(17), 7(4), 8(1) or 9(1) scales covering base of anteriormost anal-fin rays. Caudal peduncle with 14 circumpeduncular scales. Caudal fin scaled, scales present on proximal one-fifth of upper and lower caudalfin lobes.

Pectoral-fin rays i, 8(1), 9(13) 10*(15) or 11(1). Tip of pectoral fin almost reaching vertical through pelvic-fin origin. Pelvicfin rays i, 6*(32), 7(2). Supraneurals 4(1) or 5(1). Dorsal-fin rays ii (1) or iii (1), 7(1), 8(2) 9*(27), with first unbranched ray reduced in size. Dorsal-fin origin located slightly posterior to middle of standard length. Base of posteriormost dorsal-fin ray situated at vertical through anal-fin origin. First dorsal-fin Color in alcohol. Ground color tan, with chromatophores densely covering whole body, except for abdomen and along distinct unpigmented area extending from eye to caudal peduncle and forming light midlateral stripe. Lower lip, snout, top of head and dorsal portion of body densely covered by small dark chromatophores, resulting in overall countershaded color pattern. Margin of upper lip dark. Vertically elongate humeral blotch present but inconspicuous. Eight or nine dorsalmost longitudinal scale rows with scales bearing large dark blotches on anterior to central portions but fading towards scale margin. Broad, dark, slightly concave midlateral stripe extending from pectoral girdle to tip of median caudal-fin rays. Stripe diffuse, formed by scattered chromatophores. Dorsal, caudal, anal, and pectoral-fins hyaline, with small few chromatophores. Adipose fin dusky, with scattered small chromatophores ( Fig. 6 ).

Color in life. Ground color yellowish, with distinct clear midlateral yellow stripe and large, dark, ventrally curved longitudinal stripe immediately ventral to it. Stripes run from humeral region to caudal peduncle. Abdomen white to light yellow. Eye clear, with longitudinal dark stripe. Caudal fin with middle dark stripe delimited anteriorly by upper and lower yellowish areas. Specimens kept in captivity for several months have dorsal and anal fins lightly pigmented with gradients of green, yellow and red ( Fig. 7 ).

Etymology. From the Latin plumbum, meaning lead, in allusion to the color of the midlateral stripe below the unpigmented stripe in live specimens. An adjective.

Distribution. Known from headwaters of tributaries of the rio Braço Norte (rio Tapajós basin) in the Serra do Cachimbo ( Figs. 4 and 5 ).

Figures

Fig. 1. Moenkhausia chlorophthalma, holotype, MZUSP 99412, 67.4 mm SL, Brazil, Pará,Altamira, rio Treze de Maio, tributary to rio Curuá, rio Iriri basin, rio Xingu drainage.

Fig. 2. Moenkhausia chlorophthalma, aquarium specimen showing live coloration, Brazil, Pará, Altamira, rio Treze de Maio, collected with holotype.

Fig. 3. Upper and lower jaws of Moenkhausia chlorophthalma, paratype, MZUSP 97092, 43.3 mm SL; lateral view, anterior to right, SEM preparation.

Fig. 4. Collecting sites and type-localities of Moenkhausia chlorophthalma (squares) and Moenkhausia plumbea (circles). Open symbols represent type-localities.

Fig. 5. Habitats at Serra do Cachimbo: a - type-locality of Moenkhausia chlorophthalma, rio Treze de Maio, tributary of rio Curuá, rio Xingu basin, 08º45’06”S 55º02’05”W; b - type-locality of Moenkhausia plumbea, a tributary of rio Braço Norte, tributary of rio Teles Pires, rio Tapajós basin, 09º17’59”S 54º50’00”W; c - waterfall in rio Treze de Maio, 08°44’13.2”S 55° 01’51.9”W. Moenkhausia plumbea, new species by the presence of large dark blotches on the anterior to the

Fig. 6. Moenkhausia plumbea, holotype, MZUSP 99415, 49.5 mm SL, Brazil, Pará, Novo Progresso, tributary to rio Braço Norte, at bridge of BR 163 road near Air Force Base, rio Tapajós basin.

Fig. 7. Moenkhausia plumbea, aquarium specimen showing live coloration from Brazil, Pará, Novo Progresso, tributary of rio Braço Norte, rio Tapajós basin, collected with MZUSP 96849.

Fig. 8. Upper and lower jaws of Moenkhausia plumbea, paratype, MZUSP 96849, 39.1 mm SL; lateral view, anterior to right. Retroarticular and posterior, smaller teeth of dentary lost during SEM preparation.

Fig. 9. Moenkhausia petymbuaba, photographed alive, MZUSP 97530, Brazil, Pará, Altamira, tributary to rio Curuá, rio Xingu basin. Photo by M. Sabaj Pérez.