Ituglanis ina, Wosiacki & Dutra & Mendonça, 2012

Wosiacki, Wolmar B., Dutra, Guilherme M. & Mendonça, Marina B., 2012, Description of a new species of Ituglanis (Siluriformes: Trichomycteridae) from Serra dos Carajás, rio Tocantins basin, Neotropical Ichthyology 10 (3), pp. 547-554 : 548-553

Ituglanis ina , new species

Figs. 1-3

Holotype. MPEG 19613 , 62.0 mm SL, Brazil, Pará, Parauapebas, Serra dos Carajás , tributary of the left bank of rio Parauapebas , tributary of the right bank of rio Itacaiúnas , tributary of the right bank of rio Tocantins , 06°06’2.8”S 50°08’11.9”W, 20 Sep 2009, M. B. Mendonça & T. M. S. Freitas .

Paratypes. Same data as holotype, except when noticed: MPEG 17383 , 6, 11.8-42.0 mm SL, 06°05’15.6”S 50°07’56.9”W, 21 Sep 2009 ; MPEG 17384 , 4, 11.5-61.5 mm SL, 06°06’13.5”S 50°07’58.6”W, 22 Sep 2009 ; MPEG 17385 , 10, 12.5-42.5 mm SL, 06°06’13,5”S 50°07’58,6”W, 22 Sep 2009 ; MPEG 17386 , 12, 29.8- 52.0 mm SL (5 c&s, 30.5-51.2 mm SL), 06°05’15.6”S 50°07’56.9”W, 21 Sep. 2009 ; MPEG 17387 , 54.9 mm SL ; MPEG 17388 , 16, 18.3- 59.9 mm SL ; MNRJ 38989 , 2, 37.7-53.8 mm SL, same data as MPEG 17384 ; INPA 35416 , 2, 37.4-49.2 mm SL, same data as MPEG 17386 .

Diagnosis. Ituglanis ina is distinguished from all congeners by the presence of a vertical dark bar on the base of the caudal-fin rays (vs. absence), and by the lateral line (LL1 and LL2, rarely LL3) followed by a middle trunk line composed of 1-30 tiny neuromasts, extending to flank, below the dorsal fin or, at times, to caudal peduncle near the caudal-fin base, in all specimens larger than 35.0 mm SL (vs. tiny neuromasts absent). Ituglanis ina can be further distinguished from all congeners (except Ituglanis parkoi ) by general body color gray, dark on the dorsal region and gradually pale ventrally, without spots or longitudinal stripes (vs. no general gray color, with spots or longitudinal stripes). Ituglanis ina can be distinguished from I. parkoi by the fewer opercular odontodes,10-12 (vs. 22);and by the caudal-fin margin circular with attenuated edges (vs. truncated).

Description. Morphometric data presented in Table 1 . Body elongate, approximately cylindrical near head, gradually compressed toward caudal peduncle. Dorsal profile of body straight from margin of upper lip to supraoccipital, convex from that point to transverse line that passes at middle of pectoral-ray length, straight to dorsal-fin origin, and slightly concave between dorsal-fin origin and tip of caudal peduncle. Ventral profile of body convex from lower lip to transverse line through middle of interopercle, concave from that point to transverse line that passes at middle of pectoral-fin ray length, slightly convex to anal-fin origin, concave at anal-fin base, and straight to slightly concave from insertion of last anal-fin ray to base of ventral caudal-fin rays. Skin thick, especially on dorsal, anal and pectoral-fin bases.

Head longer than wide, depressed, trapezoidal in dorsal view, wider at posterior edge of opercle than between bases of maxillary barbel, anterior margin of snout slightly rounded. Region between eyes and lateral margin of head with hypertrophied and obvious adductor mandibulae muscle, in juvenile and adult specimens.

Eye round, margin not well defined, dorsally oriented, covered by thin skin in contact with lens; ocular structure visible on cutaneous surface; orbital margin not free.

Anterior nostril surrounded antero-mesially by thin fold of skin, and postero-laterally by fleshy and thick base of nasal barbel,diameter distinctly greater than posterior nostril.Posterior nostril approximately circular, same diameter as eye, occluded anteriorly by fleshy integument shaped like a half-shell.

Branchial membrane thick, united anteriorly to isthmus, forming small transverse skin fold. Gill opening relatively wide. Branchiostegal rays 8-10 (visible in c&s specimens), 4-7* externally visible. Mouth subterminal, corners directed laterally. Upper lip posteriorly continuous with head surface; anterior margin slightly rounded, in dorsal view; papillae on all surface. Lower lip distinctly narrower than upper lip, between two lateral lobes at base of inner rictal barbels; covered by papillae smaller than that on upper lip; anterior margin slightly rounded in ventral view.

Barbels long with wider fleshy bases,becoming gradually narrow toward tips. Nasal-barbel origin at posterior-lateral region of anterior nostril; distal portion reaching half opercle (5),posterior margin of opercle (24) or pectoral-fin origin (25*). Maxillary barbel reaching pectoral-fin origin (15) or surpassing that point (39*). Rictal barbel reaching margin of gill membrane (3), pectoral-fin origin (49*) or surpassing that point (2).

Interopercular patch of odontodes long, latero-ventrally oriented, 19-20* (21-25 in c&s), conical odontodes arranged in two irregular rows (antero-dorsal and postero-ventral), covered with thick integument,especially on posterior margin, with minute papillae; odontodes from antero-dorsal row smaller and straight, odontodes from postero-ventral row longer and slightly curved medially. Opercular patch of odontodes round, latero-dorsally oriented, 10, 11* or 12 (16 in c&s) conical odontodes arranged irregularly, partially covered by thick skin, mainly posterior; anteriormost odontodes smaller; posterior ones gradually larger and slightly curved medially.

Lateral line sensory canal including supraorbital branch, S1, S3, S6 (40*), or S3 and S6 (2), two opposite pores S6; incomplete infraorbital branch, I10, I11 (40*) or I11 (2); preopercular, Po1, Po2 (41); branch of lateral line, LL1 and LL2 (53*), rarely LL3 (2), tiny neuromasts of middle trunk line (40, specimens larger than 35.0 mm SL), i(3),ii(1), iii (2), v (1), ix (5), x(2), xi(1),xii(2),xiv(1), xvi(1),xvii(2),xviii(2),xix (3),xx(1*), xxi(2), xxii(1), xxiii(3), xxiv(1), xxv(2),xxvii (1), or xxx (3).

Pectoral fin trapezoidal, distal margin slightly circular, i,5 (48*) or i,6(6)rays,first ray inserted immediately below posterior margin of opercle,extending beyond margin as filament.Dorsal fin semicircular,i,6(1), i,7(3),ii,5(3),ii,6(19*),ii,7(19),iii,5(1)or iii,6 (7) rays, second or third ray not branched and first branched ray longer than others. Anal fin semicircular, slightly shorter than dorsal fin, origin on transversal line at base of first branched dorsal-fin ray, i,5 (1), i,6 (2), ii,4 (2) ii,5 (42*), ii,6 (2), iii,4 (2), or iii,5 (2) rays, last ray not branched and first two branched ones longer than others. Pelvic fin roughly rectangular,distal margin circular,anterior to dorsal-fin origin, completely covering urogenital opening, not reaching analfin origin (rarely, 2 ex.), i,2(1), i,3 (25),or i,4(28*)rays,second and third longer than others, base of medial rays of opposite fins close but not in contact.Caudal margin with circular edges and rounded borders, when expanded distally higher than at base of rays,i,5/6,i(4),i,5/5,ii(8),ii,3/5,ii(1),ii,4/5,i(1),ii,4/6,i(6), ii,4/5,ii(29*), ii,4/6,ii (1), ii,5/4,ii (2), or ii,5/5,ii (2), dorsal and ventral outer rays not branched, branched rays branching twice,but only in juveniles exclusively in central rays.Dorsalprocurrent rays 5-11* externally visible in specimens preserved in ethanol (15-19 in c&s), posterior ones long, gradually becoming short anteriorly. Ventral-procurrent rays 13-14 (visible in c&s specimens), 5-7* externally visible, posterior ones long, gradually becoming short anteriorly.Anal and urogenital openings at half distance between pelvic-fin base and anal-fin origin.

Free vertebrae 38-40.Precaudal vertebrae 17-19.Abdominal vertebrae 14-17. Caudal vertebrae 20-22.Ribs 2 or 3 pairs,first and second thickest, third thinner or absent. Dorsal-fin pterygiophores 7-8, first pterygiophore inserting anterior to neural spine of 24 th or 25 th free vertebrae.Anal pterygiophores 6, first pterygiophore anterior to hemal spine of 23 rd to 25 th free vertebrae. None (3) or one (2) vertebrae between first dorsal-fin pterygiophore and first anal-fin pterygiophore. Caudal skeleton pleurostyle, fused parahypural and hypurals 1+2; 3; 4+5 or 3+4+5.

Color in recently fixed individuals. General color gray on ground color light brown, darker on dorsal and anal-fin bases, and over dorsal midline region of head, trunk, and caudal peduncle.Gradually clearer ventrally.Abdomen white.Vertical bar over base of the caudal-fin rays, distinctly thicker and darker on the central rays. Dorsal, anal and caudal fins with tiny chromatophores scattered just over rays, larger and more evident on caudal fin.

Color in ethanol. Ground color usually light cream.Superficially, light brown pigmented,similar in small and large specimens ( Fig. 3 ); darker on dorsal midline region of head, trunk and caudal peduncle, gradually clearer ventrally. Region between eye, opercle and interopercle slightly pale,similar to region immediately lateral to eye (cheek). Upper and lower lips gray; lower lip distinctly clearer than upper lip, slightly dark in medial region. Nasal and maxillary barbels with dark gray bases,gradually light distally, until light cream color tips; maxillary barbel darker on dorsal surface than on ventral one.Rictal barbel paler than nasal and maxillary barbels,with dark gray base,gradually light distally; darker on dorsal surface than on ventral one. Rictal lobes pale, with small scattered chromatophores.Region between rictal lobes light gray, gradually light posteriorly, toward isthmus. Ventrolateral region of head light gray, gradually light medially, with sparse chromatophores forming small patches on gill membrane in medial region. Abdomen light cream, sometimes gray over posterior half. Fins pale; dorsal fin densely pigmented over thick skin on base of rays, tiny chromatophores scattered only over rays, translucent margin; anal fin similar to dorsal fin but slightly lighter; pectoral fin white, with tiny chromatophores only on rays, denser at base and over outer unbranched ray, gradually more scattered towards the margin completely translucent, ventral surface slightly lighter than dorsal surface; pelvic fin with few chromatophores only at base of rays of dorsal surface, denser on outer ray, ventral surface without or with few chromatophores at base of unbranched ray; caudal fin slightly darker than other fins, with chromatophores only on rays, dense at base, gradually sparse and small distally, toward completely translucent margin. Discreet, but distinct, vertical dark bar over base of caudal-fin rays from dorsal to ventral fold margins, distinctly thicker and darker on the central rays.

Geographic distribution. Ituglanis ina is known from tributaries of rio Parauapebas,a tributary of the rio Itacaiúnas, which is in turn a tributary of the right bank of the rio Tocantins, Serra dos Carajás, State of Pará, Brazil ( Fig. 4 ).

Etymology. The specific epithet “ ina ” is in reference to the term “inã”, which means person, a self-designation of the Karajás (Carajás) indigenous people that inhabit the Serra dos Carajás. Macro-Gê linguistic trunk, Carajás linguistic family.A noun in apposition.

Comparative material. Bullockia maldonadoi : MZUSP 36958 , 1 c&s, 45.5 mm SL, Chile, Coigüe, rio Bio Bio . Copionodon pecten : MZUSP 48962 , 4 + 3 c&s, 40.5-51.5 mm SL, Brazil, Bahia, Lençois , rio Lençois , tributary of rio Paraguaçu . Glaphyropoma rodriguesi : MZUSP 42466 , 1 c&s, 51 mm SL, paratype, Brazil, Bahia, Mucujê, rio Mucujê . Hatcheria macraei , MZUSP 35687 , 1, 67.4 mm SL, 2 disarticulated c&s, Argentina, Córdoba, Pilar, río Segundo . Ituglanis amazonicus : MPEG 3345 , 1 c&s, 42.0 mm SL, Brazil, Pará, Parauapebas, igarapé do Pojuca , rio Itacaiúnas , rio Tocantins . Ituglanis eichorniarum : MNRJ 780 A, 33.1 mm SL, Lectotype of Trichomycterus eichorniarum Miranda Ribeiro, 1912, Brazil, Mato Grosso, Cáceres, rio Paraguai . MNRJ 780 B, 24.2 mm SL, Paralectotype of Trichomycterus eichorniarum Miranda Ribeiro, 1912, Mato Grosso, Cáceres, rio Paraguai . Ituglanis gracilior : FMNH 53264 , 17.0 mm SL, holotype of Pygidium gracilior Eigenmann 1912 , Guiana, Erukin . Trichomycterus guianensis : FMNH 52676 , 64.2 mm SL, holotype of Pygidium guianensis Eigenmann, 1909 , Guiana, Aruataima Falls, upper rio Potamoro . Ituglanis laticeps : CAS 32458 , 1, 66.8 mm SL, Ecuador, Imbabura below Parabama . Ituglanis metae : CAS 118214 , 1, 76.5 mm SL, Peru, Loreto, Pebas, Cano near Pebas . CAS 124227 , 1, 70.9 mm SL, Loreto, Pebas, Cano Del Chancho near Pebas . Ituglanis parahybae : FMNH 58576 , 27.8 mm SL, holotype of Pygidium proops parahybae Eigenmann, 1918 , Brazil, Rio de Janeiro, São João da Barra, rio Paraíba . Ituglanis parkoi : MNRJ 3849 , 143.0 mm SL, holotype of Pygidium parkoi Miranda Ribeiro, 1944, Brazil, Amazonas, Benjamin Constant, rio Iticoaí . Ituglanis proops : MNRJ 781 B, 49.4-63.1 mm SL, 3 paralectotypes of Trichomycterus proops Miranda Ribeiro, 1908, Brazil, São Paulo, Iguape, rio Ribeira do Iguape . Ituglanis sp. : MNRJ 11489 , 2, 52.4-60.9 mm SL, c&s, Brazil, Goiás, Minaçu, córrego Pontilhão . Pseudostegophilus sp. : MPEG 3315 , 103.7 mm SL, Brazil, Rondônia, rio Madeira , Boca do Aripuanã . Stegophilus sp. : MPEG 3749 , 48.6 mm SL, Brazil, Pará, Belém, Igarapé Tucunduba . Trichogenes longipinnis : MZUSP 63478 , 12 + 3 c&s, 36.7-57.7 mm SL, Brazil, São Paulo, Ubatuba, Cachoeira da Piscina do Amor . Trichomycterus albinotatus : MZUSP 35817 , 2, 43.0-44.0 mm SL, Brazil, Rio de Janeiro, Visconde de Mauá, rio Preto , Cachoeira da Maromba . Trichomycterus alternatus : FMNH 58082 , 66.1 mm SL, holotype of Pygidium alternatum Eigenmann, 1917 , Brazil, rio Doce . FMNH 58083 , 31.6-59.1 mm SL, 12 paratypes of Pygidium alternatum Eigenmann, 1917 , rio Doce . Trichomycterus areolatus : CAS 15649 , 8, 66.9-95.5 mm SL, Chile, Los Lagos, río Petrohue . Trichomycterus bahianus : MZUSP 38636 , 1 paratype c&s, 50.7 mm SL, Brazil, Bahia, Una, Ribeirão Caveira . Trichomycterus brasiliensis : MZUSP 37145 , 2, 62.4-71.2 mm SL, Brazil, Minas Gerais, Nova Lima, riacho afluente do córrego Mutuca . Trichomycterus castroi : MHNCI 7643 , 1, 120.6 mm SL (1 c&s disarticulated), Brazil, Paraná, Pinhão, foz do córrego da Divisa . Trichomycterus chiltoni : CAS 57596 , 149.0 mm SL, holotype of Pygidium chiltoni Eigenmann, 1928 , Chile, Bio Bio, Concepcion, río Andalien . CAS 57597 , 40.5-138.0 mm SL, 68 paratypes of Pygidium chiltoni Eigenmann,1928 , Estero Nonguen . Trichomycterus crassicaudatus : MPEG 7931 , 1 paratype, 113.0 mm SL, Brazil, Paraná, Foz do Jordão, rio Jordão . MPEG 13057 , 1 paratype, 34.1 mm SL, Paraná, Candói, rio Jordão . Trichomycterus davisi : FMNH 60309 , 41.7 mm SL, holotype (X-ray) of Pygidium davisi Haseman, 1911 , Brazil, Paraná, Serrinha, rio Iguaçu system . Trichomycterus igobi : MPEG 13352 , holotype, 90.1 mm SL, Brazil, Paraná, Candói, rio Jordão . MPEG 13353 , 2 paratype, 72.4-82.7, Paraná, Candói, rio Sobradinho . Trichomycterus iheringi : CAS 64585 , 139.6 mm SL, holotype of Pygidium iheringi Eigenmann, 1917 , Brazil, São Paulo, Santos . CAS 64586 , 117.6-128.0 mm SL, 3 paratypes of Pygidium iheringi Eigenmann, 1917 , São Paulo, Santos . FMNH 58074 , 125.7-134.1 mm SL, 2 paratypes of Pygidium iheringi Eigenmann, 1917 , São Paulo, Sapina . Trichomycterus itatiayae: MZUSP 44501 , 4, 47.7-82.9 mm SL, c&s, Brazil, Rio de Janeiro, Resende, Bairro da Serrinha, rio Pomba , tributary of rio Pirapitinga , road to Camping Club do Brasil . Trichomycterus longibarbatus : MZUSP 67915 , 3 c&s, 44.1-56.1 mm SL, Brazil, Espírito Santo, Santa Tereza, Reserva de Nova Lombardia . Trichomycterus mboycy : MPEG 6695 , holotype, 125.7 mm SL, Brazil, Paraná, Foz do Jordão, rio Jordão . MPEG 6698 , 1 + 1 c&s paratypes, 68.2-82.3 mm SL, Paraná, Pinhão, Rio dos Touros . Trichomycterus meridae : CAS 147809 , 6, 29.4-49.0 mm SL, Venezuela, tributary of río Chama . UMMZ 145374 , 5, 74.7-95.6 mm SL, río Alberrigas at Merida . Trichomycterus mimonha : MZUSP 49486 , 3, 44.8-102.9 mm SL c&s, Brazil, São Paulo, Araçariguama, stream tributary of rio Tietê , near MAJ and BP companies . Trichomycterus mirissumba : MZUSP 44500 , 3 c&s, 60.0-83.9 mm SL, Brazil, Rio de Janeiro, Rezende, rio Pomba . Trichomycterus punctulatus : MZUSP 67826 (ROM 51725), 2, 68.3-89.8 mm SL, Peru, Cajamarca, just W of Chilete, río Jequetepeque . Trichomycterus rivulatus : MZUSP 67827 (ROM.ICH 40769), 1 c&s, 134.3 mm SL, Bolivia, La Paz District, lago Titicaca , less than 500 meters from shore . Trichomycterus stawiarski : NUPELIA J1103 , 127.7 mm SL, Brazil, Paraná, Foz do Jordão, Jordão reservoir . Trichomycterus striatus : FMNH 7579 , 71.9 mm SL, holotype of Pygidium striatum Meek & Hildebrand, 1913 , Panamá, Darien, Cana, río Cana . FMNH 26660 , 1 paratype, 53.9 mm SL, Darien, Cana, rio Cana . FMNH 26661 , 66.3 mm SL, 1 paratype of Pygidium striatum Meek & Hildebrand, 1913 , Darien, Cana , río Cana . FMNH 26662 , 43.4 mm SL, 1 paratype of Pygidium striatum Meek & Hildebrand, 1913 , Darien, Cana , río Cana . FMNH 55233 , 53.8 mm SL, 1 paratype of Pygidium striatum Meek & Hildebrand, 1913 , Darien, Cana, Cana . Trichomycterus taroba : MPEG 6689 , holotype, 52.7 mm SL, Brazil, Paraná, Foz do Jordão, Jordão reservoir . MPEG 6690 , 15 paratypes, 30.7-58.7 mm SL, Paraná, Foz do Jordão, Jordão reservoir . Trichomycterus triguttatus : MZUSP 44543 , 3, 52.1-77.7 mm SL, c&s, Brazil, São Paulo, Silveiras, rio da Bocaina , Bairro Bom Jesus da Bocaina . Trichomycterus zonatus : FMNH 58573 , 54.0 mm SL, holotype Pygidium zonatum Eigenmann, 1918 , Brazil, São Paulo, rio Água Quente . FMNH 58574 , 43.0-48.5 mm SL, 2 paratypes of Pygidium zonatum Eigenmann, 1918 , São Paulo, rio Água Quente .

Figures

Fig. 1. Ituglanis ina, MPEG 19613,holotype, 62.0 mm SL, inverted lateral view of the right side;Brazil,Pará,Parauapebas,Serra dos Carajás, tributary of the Parauapebas, tributary of the rio Tocantins.

Fig. 2. Ituglanis ina, MPEG 19613, holotype; (a) dorsal and (b) ventral view of the head. Scale bar = 5 mm.

Fig. 3. Ituglanis ina, paratypes, MPEG 17388. Left lateral view showing the gray color pattern and the vertical dark bar on the base of the caudal-fin rays, in large to small specimens. Black spots over body are nematodes’ cysts. Scale bar = 1 cm.

Fig. 4. Map of part of the northern and northeastern South America showing the distribution of Ituglanis ina. Star represents the type locality.