Hemigrammus parana, Marinho, Manoela M. F., Carvalho, Fernando R., Langeani, Francisco & Tatsumi, Vio L., 2008

Marinho, Manoela M. F., Carvalho, Fernando R., Langeani, Francisco & Tatsumi, Vio L., 2008, A new Hemigrammus Gill from upper rio Paraná system, Southeastern Brazil (Characiformes: Characidae), Zootaxa 1724, pp. 52-60 : 53-56

Hemigrammus parana , new species

( Fig. 1 )

Holotype. DZSJRP 6217, 24.9 mm SL, rio Grande near the old sand port, known as Velho Adão, municipality of Santa Clara D’Oeste, São Paulo state, Brazil, 20°01’27.2”S, 50°54’46.6”W, F.R.Carvalho and J. O.Carvalho, 08.i.2004.

Paratypes. All from Brazil, upper rio Paraná system. DZSJRP 8781, 1262/3, 13.3–28.0 mm, Ribeirão Can-Can, old port, Ilha Solteira reservoir, municipality of Santa Clara D´Oeste, São Paulo state, 20°01’26.5”S 50°54’44.5”W, F.Langeani, R.S.Costa-Ferreira, F.R.Carvalho, M.M.F.Marinho, J.P.Serra and F.L.R.Sousa, 23.viii.2006; DZSJRP 8809, 208/5, 12.2–30.8 mm, headwater of Brejo Comprido, Ilha Solteira reservoir, municipality of Aparecida do Taboado, Mato Grosso do Sul state, 20°10’34.4”S 51°12’18.6”W, F.Langeani, R.S.Costa-Ferreira, F.R.Carvalho, M.M.F.Marinho, J.P.Serra and F.L.R.Sousa, 26.viii.2006; DZSJRP 9051, 1399, 11.8–29.5 mm, Córrego da Anta, Fazenda São Félix, Ilha Solteira reservoir, municipality of Aparecida do Taboado, Mato Grosso do Sul state, 20°23’57.4”S 51°07’57.3”W, F.Langeani, R.S.Costa-Ferreira, F.R.Carvalho, M.M.F.Marinho, J.P.Serra and F.L.R.Sousa, 29.viii.2006; DZSJRP 10796, 359/34, 14.8–26.1 mm, 3 c&s, same data as holotype; LIRP 6004 (ex- DZSJRP 10796), 20, 19.8–25.0 mm; MCP 41759 (ex- DZSJRP 8781), 20, 20.7–25.2 mm; MNRJ 31197 (ex-DZSJRP 8781), 20, 20.7–27.9 mm; MZUEL 4904 (ex- DZSJRP 10796), 20, 25.7– 18.8 mm; MZUSP 95001 (ex-DZSJRP 8781), 30, 19.3–26.8 mm; UFRGS 8869 (ex-DZSJRP 9051), 50/16, 22.2–26.7 mm.

Diagnosis. Hemigrammus parana differs from all congeners, except Hemigrammus levis , by the absence of a humeral spot and presence of a conspicuous black spot, restricted to caudal fin, roughly triangular or rectangular, extending from base to tip of middle caudal-fin rays (its greatest depth at base of caudal-fin rays). It differs from H. levis by having 18–23 (mode 21) unbranched anal-fin rays (vs. 16–18), largest tooth of the inner row of premaxilla and dentary with 5 cusps (vs. 7–9 cusps), anterior portion of longitudinal band as a broad uninterrupted pigmented area (vs. anterior portion of longitudinal band with a small round concentration of chromatophores at humeral region, surrounded by unpigmented areas anterior and posteriorly), distance of snout to anal-fin origin 58.6–65.9% SL, mean 62.0% (vs. 63.7–73.9% SL, mean 68.8%), anal base length 25.1–32.5% SL, mean 29.2% (19.3–24.7% SL, mean 22.0%), upper jaw length 39.6–48.3% HL (vs. 34.3–39.5% HL),

Description. Morphometric data presented in Table 1 . Overall size small (22.2–30.2 mm SL). Body compressed, moderately elongate, greatest body depth at vertical through dorsal-fin origin. Dorsal profile of head convex from tip of upper jaw to vertical through anterior nostril; straight to slightly concave from that point to tip of supraoccipital spine. Dorsal profile of body slightly convex from posterior tip of supraoccipital spine to dorsal-fin origin; straight and posteroventrally inclined from dorsal-fin origin to adipose-fin origin and slightly concave along caudal peduncle. Ventral profile of body convex from tip of lower jaw to pelvic-fin origin; straight from that point to anal-fin origin; straight and posterodorsally slanted along anal-fin base. Ventral profile of caudal peduncle slightly concave.

Eyes relatively large, lacking distinct adipose eyelid. Jaw equal, mouth terminal. Maxillary extending posteriorly anterior margin of eye, slightly curved, aligned approximately at 45 degrees angles relative to longitudinal axis of body. Premaxillary teeth in two rows: outer with 2(7), 3(29), 4*(20), or 5(3) tricuspid teeth (rarely pentacuspid); inner tooth row with 5 tri-pentacuspid teeth. Dentary with 3(2), 4*(54) or 5(2) large tri to pentacuspid teeth, followed by a series of 5–10 small conical teeth. Antero and posterodorsal border of maxillary relatively straight. Maxilla with 0(5), 1*(29), 2(17), or 3(5) tricuspid teeth along anteroventral margin ( Fig. 2 ). Central median cusp in all teeth longer than remaining cusps; cusp tips slightly curved posteriorly and towards inside of mouth.

Scales cycloid, with few radii, relatively small, and weakly implanted. Lateral line incomplete, slightly decurved anteriorly to vertical through distal tip of pectoral fin; perforated scales of lateral line 6(7), 7(19), 8*(15), 9(13), 10(2), or 11(1); longitudinal scales series including pored scales 26(2), 27(4), 28(6), 29(8), 30(6), 31(10), 32*(12), 33(6), or 34(1); 5 (58) scales rows between dorsal-fin origin and lateral line; scales rows between lateral line and pelvic-fin insertion 3(18) or 4*(32). Predorsal scales 9(13), 10*(40), or 11(6) scales. Scale sheath along anal-fin base with 2(2), 3(10), 4(20), 5(14), or 6*(1) in a single row. Circumpeduncular scales 10*(14), 11(35) or 12(6). Axillary scale present.

Dorsal-fin rays ii, 9 (58); first unbranched ray approximately one-half of second unbranched ray. Dorsalfin origin at midbody, at vertical through anterior third of pelvic- fin base, and base of its last ray at vertical through second or third anal-fin branched ray. Tip of longest ray of adpressed dorsal fin at vertical through 11th and 12th branched anal-fin rays. First dorsal-fin pterygiphore inserting behind neural spine of 6th(2) or 7th(1) vertebra. Adipose fin present, located approximately at vertical through second or third last branched of analfin rays. Pectoral fin with i, 9(2), 10(17), 11*(37), or 12 (3) rays. Pelvic fin with i, 6(7) or 7*(52) rays; tip of longest ray reaching anal fin. Anal-fin rays iii, 18(1), 19(9), 20(14), 21*(17), 22(14), or 23(4). Caudal fin forked, lobes slightly rounded, similar in size, with i, 9, 8, i rays (58). Caudal fin partially covered with very small and weakly implanted scales along first third of upper and first half of lower caudal-fin lobes. Dorsal procurrent caudal-fin rays 10(3), ventral procurrent caudal-fin rays 8(2) or 9(1).

Branchiostegal rays 4. First gill arch with 6 gill rakers on epibranchial, 10 in ceratobranchial, and 3 on hypobranchial. Precaudal vertebrae 15 and caudal vertebrae 17(2) or 18(1). Supraneurals 4.

Color in alcohol. Overall ground coloration of body pale. Infraorbital and opercular areas silvery. Anterior portion of lower jaw, dorsal portion head, snout, and dorsal midline of body covered by small dark chromatophores. Longitudinal body band dusky, originating as a broad pigmented area from opercle to vertical through tip of longest pectoral-fin ray, becoming more intense, slender and sometimes silvery from this point to end of caudal peduncle. Scales of second or third longitudinal rows above lateral line bordered by few chromatophores, forming a slight reticulate pigmentation. Humeral spot absent. Dorsal, adipose, pectoral, pelvic, and anal fins almost entirely hyaline, with few scattered dark cromatophores. Posterior half of caudal-fin lobes with diffuse chromatophores, making fin slightly darkish. Conspicuous black caudal spot roughly triangular or rectangular, extending from base to tip of middle caudal-fin rays, its greatest depth at base of caudal rays; sometimes, caudal spot lighter, not reaching the tip of middle caudal-fin rays.

Color in life. Overall coloration silvery. Intense silvery longitudinal band on body. Dorsal, adipose, pectoral, pelvic, and anal fins yellowish; median portion of caudal lobes reddish or orange. Conspicuous black caudal spot, extending from base to tip of middle caudal-fin rays.

Sexual dimorphism. Secondary sexually dimorphic characters, such as hooks on pelvic and anal-fin rays, were not found on examined specimens.

Distribution. Hemigrammus parana only occurs in the area of influence of the Ilha Solteira reservoir, upper Paraná system, southeastern Brazil, throughout margins of rio Grande, rio Paraná , rio Paranaíba, and rio São José dos Dourados ( Fig. 3 – 4 ).

Etymology. The specific name parana refers to the type locality river, the rio Paraná , which originates after the confluence of the rio Grande and the rio Paranaíba, where the new species occurs.

Ecological notes. Hemigrammus parana is very common and specially abundant in backwater margins, from 0.3 to 1.30 m depth, occurring associated with Poaceae and macrophytes ( Ceratophyllum sp., Egeria densa , Eichornia spp., Ludwigia sedorde , and Salvinia sp.). Stomach contents examination of two specimens showed a large volume of Spirogyra sp., Cladocera, sediments (sand) and unidentified organic matter. Several species were collected syntopically with Hemigrammus parana , the most frequent were Astyanax altiparanae Garutti & Britski , Crenicichla britskii Kullander , Geophagus proximus (Castelnau, 1855) , Gymnotus carapo Linnaeus, 1758 , Hoplias malabaricus (Bloch) , Hyphessobrycon eques (Steindachner) , Laetacara sp., Metynnis maculatus (Kner) , Moenkhausia sp., Pamphorichthys hollandi (Henn) , Roeboides descalvadensis Fowler , Satanoperca pappaterra (Heckel) , Serrapinnus notomelas (Eigenmann) , and Serrasalmus maculatus Kner.

Figures

FIGURE 1. Hemigrammus parana, holotype, DZSJRP 6217, 24.9 mm SL, rio Grande, near the old port of sand, known as Velho Adão, municipality of Santa Clara D’Oeste, São Paulo state, upper rio Paraná drainage, Brazil.

FIGURE 2. Hemigrammus parana, paratype, DZSJRP 10746. Premaxillary, maxillary and dentary, right side. Scale bar 1 mm.

FIGURE 3. Geographic distribution of Hemigrammus parana in the upper rio Paraná drainage, Brazil.

FIGURE 4. Type locality of Hemigrammus parana, rio Grande, near the old sand port known as Velho Adão, municipality of Santa Clara D’Oeste, São Paulo state, upper rio Paraná drainage, Brazil.

Tables

TABLE 1. Morphometric data for holotype and 58 paratypes of Hemigrammus parana from the upper rio Paraná system. Standard length is expressed in millimeters. SD = standard deviation.

	Holotype	Paratypes	Mean	SD
Standard length	24.9	22.2 – 30.2	24.4	1.3
Percentages of SL
Depth at dorsal-fin origin	30.9	26.7 – 33.8	30.2	1.5
Snout to dorsal-fin origin	53.4	50.6 – 55.4	52.3	1.1
Snout to pelvic-fin origin	49.0	45.1 – 49.6	47.2	1.1
Snout to anal-fin origin	63.4	58.6 – 65.9	62.0	1.4
Caudal peduncle depth	11.2	8.4 – 11.4	9.8	0.7
Caudal peduncle length	12.0	9.6 – 15.2	12.6	1.3
Pectoral-fin lenght	21.3	19.8 – 25.8	21.7	1.1
Pelvic-fin lenght	16.9	14.7 – 20.6	17.0	1.3
Anal-fin lenght	18.9	16.5 – 23.2	20.0	1.4
Anal-fin base length	29.3	25.1 – 32.5	29.2	1.6
Dorsal-fin origin to pectoral-fin origin	38.9	34.5 – 41.0	37.3	1.2
Dorsal-fin origin to eye	39.3	35.0 – 40.6	37.5	1.1
Dorsal-fin origin to adipose-fin origin	35.3	31.3 – 40.1	36.5	1.5
Pelvic-fin origin to anal-fin origin	16.0	14.3 – 19.1	16.4	1.1
Dorsal-fin length	27.3	21.0 – 31.7	27.4	2.0
Dorsal-fin base length	12.4	11.0 – 14.3	12.8	2.0
Head depth	26.5	23.2 – 30.4	25.6	1.3
Head length	25.3	23.6 – 28.1	25.9	0.9
Percentages of HL
Snout length	25.3	22.3 – 30.5	25.1	1.7
Upper jaw lenght	41.2	39.6 – 48.3	43.5	2.3
Horizontal orbital diameter	47.6	42.5 – 53.6	48.0	2.1
Interorbital width	34.9	29.4 – 38.1	33.1	1.7