Trichomycterus tupinamba, Wosiacki & Oyakawa, 2005

Wosiacki, Wolmar Benjamin & Oyakawa, Osvaldo Takeshi, 2005, Two new species of the catfish genus Trichomycterus (Siluriformes: Trichomycteridae) from the rio Ribeira de Iguape Basin, Southeastern Brazil, Neotropical Ichthyology 3 (4), pp. 465-472 : 466-469

Trichomycterus tupinamba , new species Figs. 2-4

Holotype. MZUSP 62382 , 86.5 mm SL, Brazil, São Paulo: rio Betari, tributary of rio Ribeira de Iguape, in front of the camping area of Núcleo Santana , Parque Estadual Turístico do Alto Ribeira ( PETAR), Iporanga, P. Gerhard, R. Moraes & J. Sturve, 22 Jan 2000.

Paratypes. Brazil. São Paulo: MZUSP 84094 , 4 , 28.2–70.6 mm SL, collected with holotype ; MZUSP 67911 , 2 (C&S), 44.4-54.0 mm SL, rio Betari , PETAR, Iporanga, P. Gerhard & S. Buck, Mar 1999 ; MZUSP 63495 , 1 , 38.2 mm SL, rio Betari, Iporanga, S. Buck , 26 Jul 1996 ; MZUSP 62362 , 1 , 43.1 mm SL, rio Iporanga, Iporanga , R. Moraes & J. Sturve, 20 Jan 2000 ; MPEG 7895 , 5 , 32.8 – 61.2 mm SL, rio Betari , PETAR, Iporanga, P. Gerhard, S. Buck, Sílvia, Jura, Anésio & R. Moraes, Mar 1999 .

Diagnosis. Trichomycterus tupinamba differs from all other species of the subfamily Trichomycterinae by the following unique combination of characters: first pectoral-fin ray not prolonged as a filament (vs. prolonged), caudal fin truncate with attenuated edges (vs. rounded), two paired supraorbital pores s6 (vs. pores united as a single supraorbital pore s6), eye dorsally oriented (vs. dorsolaterally oriented), mouth subterminal (vs. terminal), anal and urogenital openings mid-way between pelvic-fin margin and anal-fin origin (vs. nearer to anal-fin origin), dark spot at base of nasal barbel (vs. dark spot absent), longitudinal row of dark spots along midline of flank from opercle to caudal-fin base (vs. longitudinal lateral series of spots absent), pectoral girdle width 13.1-17.7% SL, and caudal peduncle depth 8.7-10.3% SL.

Description. Morphometric data for holotype and paratypes are given in Table 1.

Body elongate, roughly cylindrical close to head and gradually more compressed towards caudal fin. Dorsal and ventral profiles of trunk slightly convex. Dorsal and ventral profiles of caudal peduncle straight ( Figs. 2 and 3). Integument thick, especially over base of dorsal and anal fins.

Head wide and depressed, trapezoidal in dorsal view, slightly longer than wide or as long as wide (75.8-100.9 % HL), width at posterior tip of opercle greater than width at nostril, anterior margin of snout slightly rounded ( Fig. 4 ). Lateral region of eye slightly swollen by jaw muscles in large and small specimens. Dorsal and ventral profiles of head straight. Eye rounded, without well-defined rim, dorsally oriented, covered by thin skin in contact with center from surface of eyeball. Ocular structures readily visible on surface of skin, not deeply sunken. Orbital rim not free. Anterior nostril surrounded by fleshy flap of integument. Posterior nostril surrounded anteriorly by thin flap of integument. Anterior and posterior nostrils approximately same diameter as eye. Gill membranes thick, attached across isthmus only at anteriormost point, forming a small free fold across isthmus. Gill openings not constricted. Branchiostegal rays 7-8 (only 4 or 5 visible externally from below). Mouth subterminal, its corners laterally oriented. Lower lip with conspicuous lateral fleshy lobes, internal to origin of rictal barbel. Anterior margin of upper lip slightly rounded. Small papillae on external surface of upper lip and large papillae on inner surface of upper lip. Upper lip continuous with dorsal surface of head. Barbels long (nasal 35.5-54.2; maxillary 49.7-75.8; and rictal barbel length 41.7-60.6 % HL). Barbels with large base and narrowing gradually towards tip. Nasal barbel reaching to, or slightly beyond, posterior rim of eye; maxillary barbel reaching middle of interopercular patch of odontodes; rictal barbel reaching anterior most interopercular odontodes. Origin of nasal barbel on posterolateral portion of integument flap around anterior nostril. Interopercular patch of odontodes long, with 34-36 conical odontodes covered by thick integument (14-17 externally visible in alcohol specimens), external series smaller and straight, internal series larger, curved medially. Opercular patch of odontodes rounded, with 23-26 conical odontodes, anterior ones smaller and straight, posterior ones larger and curved medially. Sensory canals composed of complete supraorbital canal and incomplete infraorbital canal. Infraorbital anterior section pores i1 and i3, and posterior section pores i10 and i11. Supraorbital pores s1, s2 and s6. Two paired pores s6.

Pectoral-fin margin truncate, 8 rays, only first one unbranched, first the longest without a filamentous extension. Dorsal-fin margin semi circular, 12 rays (9 visible in intact specimens) rays, third through twelfth rays branched, third and fourth the longest. Anal fin slightly elongate in overall shape, smaller than dorsal fin, 9 rays (7 visible in intact specimens), third through ninth branched, third the longest, origin at vertical through seventh dorsal-fin ray. Pelvic-fin origin anterior to dorsal-fin origin, rounded margin, distant one half of its length from urogenital and anal openings, 5 rays, only first one unbranched, second and third rays longest. Caudalfin margin rounded with attenuated edges, distinctly deeper than remaining caudal region, 13 principal rays, dorsal and ventral external principal rays unbranched, branched rays splitting twice. Dorsal lobe procurrent rays 15-16. Ventral procurrent rays 10. Only first dorsal and ventral caudal-fin accessory rays visible. Anal and urogenital openings midway between pelvic-fin margin and anal-fin origin.

Free vertebrae 39-40. Precaudal vertebrae 16-17. Caudal vertebrae 23. Ribs 14-15 pairs, first and second thickest, 13 and 14 longest, last rudimentary free ribs. Dorsal-fin pterygiophores 8, first pterygiophore inserting anterior of neural spine of 19 th or 20 th free vertebrae. Anal pterygiophores 6, first pterygiophore anterior of hemal spine of 23 rd to 25 th free vertebrae. Caudal skeleton pleurostyle, hypurals 4+5, and hypural 3, or hypurals 3+4+5, and fused parahypural and hypurals 1+2.

Color in alcohol. Refer to figures 2 to 4 for general view of color pattern in alcohol. Dorsal surfaces of head, trunk and caudal peduncle gray, darker over occipital region, becoming gradually lighter toward caudal peduncle. Dark stripe running between eye and anterior nostril. Thick skin surrounding opercular patch of odontodes dark. Narrow, dark midlateral stripe formed by closely spaced (sometimes continuous) black spots from opercle to vertical through anal-fin origin, and continuing posteriorly to caudal peduncle as series of irregularly spaced spots. Mid-lateral stripe darker in small specimens (28.2-58.8 mm SL), gradually lighter in larger specimens (59.6-86.5 mm SL). Surface under dark lateral stripe pale, without pigmentation in small specimens (28.2-58.8 mm SL), and with few scattered small spots near anal fin and ventral half of caudal peduncle. Dorsal surface of pectoral-fin base with few chromatophores, gradually scattered towards margin. Ventral surface of pectoral and pelvic fins unpigmented. Base of dorsal and anal fin with chromatophores, more scattered towards margin over rays. Dorsal fin darker than anal fin. Few chromatophores on caudal-fin rays, gradually more scattered towards margin. Base of nasal barbel dark, becoming gradually lighter towards the tip; maxillary barbel pale with few small dusky spots on dorsal surface. Rictal barbel unpigmented. Upper and lower lips unpigmented.

Distribution. Known from the localities of the type series, Etymology. The specific name tupinamba is the name of the rivers Betari and Iporanga, both tributaries of the rio Ribeira indigenous tribe who lived in the eastern region of the São de Iguape. Paulo State in the XVI and early XVII centuries. Tupinamba ,

in Tupy language, meaning the first or the ancient, relationships to the indigenous people. A noun in apposition. It is Table 1. Morphometric and meristic data for Trichomycterus

especially interesting because according to Wosiacki (2002), tupinamba and T. jacupiranga (Hol = Holotype).

Trichomycterus sp. n. (rio Betari) (= T. tupinamba ) is the basalmost species in the assemblage Trichomycterus sensu strictu.

Ecological notes. The rio Betari at PETAR, the type locality of Trichomycterus tupinamba , is a clearwater river with strong to moderate current flowing over rocky beds intercalated with pools in karstic area. The river runs in an alluvial valley bor- dered by adjacent hills, and the riparian vegetation is composed of relatively well-preserved forest. Bellow the PETAR there are several human settlements near the rio Betari which release sewage into the river .

Trichomycterus tupinamba and other siluriforms are found associated with stones and vegetable debris on the bottom. The following species of fish occur syntopically with Trichomycterus tupinamba : T. davisi , Isbrueckerichthys alipionis (Gosline) , Neoplecostomus ribeirensis Langeani , Harttia kronei Miranda-Ribeiro , Rhamdioglanis frenatus Ihering , Chasmocranus lopezi Miranda-Ribeiro , Bryconamericus microcephalus (Miranda-Ribeiro) , and Characidium pterostictum Gomes.

Figures

Fig. 2. Trichomycterus tupinamba, holotype, MZUSP 62382, 86.5 mm, lateral view of the right side.

Fig. 4. Trichomycterus tupinamba, holotype, MZUSP 62382, 86.5 mm, dorsal view of the head. Scale bar = 5 mm.