Ituglanis boitata, new species
Creators: name: Ferrer, Juliano
name: Donin, Laura M.
name: Malabarba, Luiz R.
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Siluriformes
Trichomycteridae
Ituglanis
Ituglanis boitata

description: Ituglanis boitata, new species
(Figs. 1–2–3–4 a–5, Table 1)
Ituglanis sp. Malabarba et al. 2013: 89 (photo, brief description, distribution map).
Ituglanis sp. G Datovo & de Pinna 2014: 3 (listed in comparative material), 11 (remarks on musculature).
Holotype. UFRGS 18455 (tec), 102.9 mm SL, Brazil, Rio Grande do Sul State, Maquiné, rio Maquiné at road RS– 484 between Maquiné and São Francisco de Paula, rio Tramandaí basin, 29°31’26”S 50°18’56”W, 29 Jan 2014, L. R. Malabarba, P. C. Silva & U. Santos.
Paratypes. All from Brazil. Rio Grande do Sul State: MCN 9438, 1, 88 mm SL, Maquiné, rio Maquiné, rio Tramandaí basin, 4 Mar 2000, R. M. Mansan. MCN 18601, 1, 83.2 mm SL, Itati, arroio Bananeiras, rio Tramandaí basin, 29º25’16”S 50º10’05”W, 20 Sep 2006, J. Ferrer, M. A. Azevedo & R. Hirano. MCP 10800, 1, 46.7 mm SL, Três Forquilhas, rio Três Forquilhas, rio Tramandaí basin, 29°32’01”S 50º03’59”W, 25 May 1986, C. A. Lucena, L. R. Malabarba & R. E. Reis. MCP 14153, 1, 50.5 mm SL, Itati, rio Três Forquilhas, rio Tramandaí basin, 29°30’S 50° 04’58”W, 12 Dec 1989, C. Weber, P. Azevedo, S. Muller & Z. M. Lucena. MCP 23673, 2, 42.8–67.9 mm SL, Itati, arroio do Padre, rio Tramandaí basin, 29°29’09”S 50° 07’14”W, 20 Jul 1999, E. H. L. Pereira, J. F. P. da Silva & R. E. Reis. MCP 23694, 1, 50.7 mm SL, Morrinhos do Sul, rio Mengue, rio Mampituba basin, 29°14’55”S 49°55’30”W, 20 Jul 1999, E. H. L. Pereira, J. F.P. da Silva & R. Reis. MCP 25283, 2, 48.9–53.4 mm SL, Terra de Areia, rio Três Pinheiros at road to Itati, rio Tramandaí basin, 29°31’36”S 50°06’21”W, 29 Dec 1999, L. Malabarba, J. F. P. da Silva, T. Borges & V. Bertaco. MCP 25330, 1, 52.0 mm SL, Terra de Areia, rio Três Forquilhas, rio Tramandaí basin, 29°30’43”S 50°05’31”W, 29 Dec 1999, L. Malabarba, J. F. P. da Silva, T. Borges & V. Bertaco. MZUSP 116532, 1, 85.7 mm SL, Maquiné, rio do Ouro at Barra do Ouro, rio Tramandaí basin, 29º35’13”S 50º17’00”W, 14 Jan 2011, C. Vogel, G. Rosa & R. Paesi. MZUSP 116533, 1, 62.4 mm SL, Maquiné, rio Encantado at Barra do Ouro, rio Tramandaí basin, 29º33’39”S 50º15’23”W, 17 Dec 2010, C. Vogel, G. Rosa & L. Artioli. MZUSP 116434, 2, 38.3–56.4 mm SL, Maquiné, rio Encantado at Barra do Ouro, rio Tramandaí basin, 29º33’39”S 50º15’23”W, 14 Oct 2010, B. Meneses, C. Vogel, F. Becker & L. De Fries. UFRGS 3245, 5 (1 ms), 27.7–32.2 mm SL, Três Forquilhas, rio Três Forquilhas, rio Tramandaí basin, 29°31’60”S 50°04’60”W, 20 Aug 1983, UFRGS staff. UFRGS 8833, 1, 82.3 mm SL, Maquiné, rio Amolar Faca at Barra do Ouro, rio Tramandaí basin, 29°32’19”S 50°14’46”W, 6 Jan 2007, C. Fialho, J. Ferrer & L. R. Malabarba. UFRGS 12739, 1, 57.8 mm SL, Três Forquilhas, rio Três Forquilhas, rio Tramandaí basin, 29°28’20”S 50°07’10”W, 24 Feb 2010, R. B. Dala-Corte & V. R. Lampert. UFRGS 16064, 1 (c&s), 49.5 mm SL, Morrinhos do Sul, rio dos Mengues, rio Mampituba basin, 29°23’56”S 49°55’01”W 15 Jul 2008, L. G. Artioli & V. R. Lampert. UFRGS 17080, 1 (c&s), 42.5 mm SL, Maquiné, rio Encantado at Barra do Ouro, rio Tramandaí basin, 29º33’39”S 50º15’23”W, 14 Oct 2010, B. Meneses, C. Vogel, F. Becker & L. De Fries. UFRGS 17081, 2, 45.6–72.8 mm SL, Maquiné, rio Encantado at Barra do Ouro, rio Tramandaí basin, 29º33’39”S 50º15’23”W, 2 Dec 2010, C. Vogel, G. Rosa & J. Ferrer. UFRGS 17082, 1, 63.6 mm SL, Maquiné, rio do Ouro at Barra do Ouro, rio Tramandaí basin, 29º35’13”S 50º17’00”W, 25 Nov 2010, C. Vogel, G. Rosa & R. Paesi. UFRGS 17083, 1, 63.2 mm SL, Maquiné, rio Encantado at Barra do Ouro, rio Tramandaí basin, 29º33’39”S 50º15’23”W, 19 Feb 2011, C. Vogel, R. Paesi & V. Lampert. UFRGS 17084, 1, 122.6 mm SL, Maquiné, rio do Ouro at Barra do Ouro, rio Tramandaí basin, 29º35’13”S 50º17’00”W, 18 Feb 2012, C. Vogel, R. Paesi & V. Lampert. UFRGS 17085, 1, 52.6 mm SL, Maquiné, rio Maquiné at Barra do Ouro, rio Tramandaí basin, 29º38’50”S 50º13’02”W, 8 Oct 2010, B. Meneses, C. Vogel, F. Becker & L. De Fries. UFRGS 17086, 1, 109.6 mm SL, Maquiné, rio do Ouro at Barra do Ouro, rio Tramandaí basin, 29º35’13”S 50º17’00”W, 13 Apr 2011, C. Vogel, G. Rosa & J. R. Barradas. UFRGS 17087, 1, 96.3 mm SL, Maquiné, rio Encantado at Barra do Ouro, rio Tramandaí basin, 29º33’39”S 50º15’23”W, 15 Jan 2011, C. Vogel, G. Rosa & R. Paesi. UFRGS 17617, 5 (1 c&s; 2 tec), 43.0– 66.2 mm SL, Maquiné, arroio Água Parada at Barra do Ouro, rio Tramandaí basin, 29°40’19”S 50°12’12”W, 24 Apr 2013, L. Caetano, J. Gomes & N. Venturelli. UFRGS 19180, 5 (tec), 61.0– 88.7 mm SL, Maquiné, arroio Garapiá at Barra do Ouro, rio Tramandaí basin, 29°30’47”S 50°15’04”W, 19 Oct 2012, B. Meneses, F. Becker & R. B Dala-Corte. Santa Catarina State: MCP 29250, 1, 31.7 mm SL, Praia Grande, unnamed stream tributary to rio Mampituba, 29º12’19”S 49º58’22”W, 25 Mar 2002, J. F. P. Silva. & V. Bertaco. MCP 23633, 1, 65.4 mm SL, Criciúma, rio do Cedro, rio Araranguá basin, 28º42’42”S 49º33’57”W, 22 Jul 2002, E. H. L. Pereira, J. F. P. da Silva & R. Reis. UFRGS 17219, 1 (tec), 75.5 mm SL, Praia Grande, rio do boi, rio Mampituba basin, 29°12’07”S 50°03’01”W, 1 Dec 2012, C. Bartzen, J. Ferrer, P. Lehmann, F. Monte, L. Santos & U. W. E. Schulz.
Hologenetype COI. GenBank accession numbers KR 020519 (voucher tec 3848) on lot UFRGS 18455 (holotype). Paragenetypes COI. GenBank accession numbers KR 020520 (voucher tec 4883B) and KR 020522 (voucher tec 4883A) on lot UFRGS 19180, KR 020521 (voucher tec 4874) on lot UFRGS 19157.
Non-type material. All from Brazil. Rio Grande do Sul State. UFRGS 19157, 1 (tec), 24.8 mm SL, Terra de Areia, rio Sanga Funda at road BR 101 in Km 53, tributary to lagoa dos Quadros, 29°37’55”S 50°06’03”W, 25 Mar 2014, R. Angrizani, J. Ferrer, L. R. Malabarba & U. Santos. Santa Catarina State. MCP 48017, 1, 62.4 mm SL, Santa Catarina State, Treviso, rio Pio, rio Araranguá basin, 28º29’32”S 49º29’19”W, Apr 2013, C. Feltrin.
Diagnosis. Ituglanis boitata is distinguished from congeners with the exception of I. bambui Bichuette & Trajano; I. boticario Rizzato & Bichuette; I. paraguassuensis Campos-Paiva & Costa and I. proops (Miranda Ribeiro) by the supraorbital canal of the cephalic laterosensory system interrupted between nasal and frontal sections and the presence of pore s2 [Fig. 2; vs. supraorbital canal uninterrupted and pore s2 absent (presence of pore s2 is variable in I. bambui; Datovo pers. comm.)]. Ituglanis boitata differs from I. bambui, I. boticario, I. paraguassuensis and I. proops in the larger number of vertebrae (41–42 vs. less than 40 vertebrae). Ituglanis boitata is further distinguished from I. bambui, I. boticario and I. paraguassuensis by the anterior cranial fontanel drop-shaped slightly larger than the posterior fontanel (Fig. 2; vs. the anterior cranial fontanel absent in I. bambui and I. boticario; elongated, distinctly larger than the posterior fontanel in I. paraguassuensis). Ituglanis boitata is further distinguished from I. boticario and I. paraguassuensis in body coloration (Fig. 1; the lateral surface of body with small dark brown blotches equivalent to eye circumference and numerous tiny dark brown dots vs. the lateral surface of body covered with a single layer of black blotches distinctively larger than eye diameter in I. paraguassuensis; with longitudinal stripes in I. boticario). Ituglanis boitata is further distinguished from I. bambui, I. boticario and I. paraguassuensis by the upper caudal plate with hypural 3 autogenous (Fig. 3; vs. the upper caudal plate with hypural 3, 4, and 5 fused). Ituglanis boitata is further distinguished from I. proops in the number of branched rays in dorsal fin [modally seven (observed in 40 of 45 analyzed specimens) vs. modally six (observed in 23 of 24 analyzed specimens)], the absence of a posterolateral process in the tendon-bone supraorbital (Fig. 2; vs. presence), and the length of the interopercular patch of odontodes (Fig. 4, 22.7–31.4 vs. 35.2–43.1 mm of HL).
Description. Morphometric data in Table 1. Body elongate, trunk roughly cylindrical, gradually compressed towards caudal fin. Dorsal profile of trunk convex along anterior half then straight to insertion of dorsal fin. Ventral profile of trunk straight to slightly convex. Dorsal and ventral profile of caudal peduncle straight or with posterior portion deeper.
Head depressed, trapezoidal from dorsal view, wider posteriorly. Dorsal profile straight and ventral profile straight to slightly convex. Snout straight to slightly round from dorsal view. Eyes located in posterior region of head just behind posterior nostril, dorsally oriented but also visible from lateral view; orbital rim not free, eyes covered with skin thin and transparent.
Nostrils slightly smaller than eye diameter. Anterior nostril surrounded by fleshy flap of integument posterolaterally continuous with nasal barbel. Posterior nostril surrounded anterolaterally by thin flap of integument. Gill openings not constricted but united with isthmus anteriorly forming free fold. Mouth subterminal straight or with corners slightly oriented posteriorly. Lower lip with a pair of conspicuous fleshy lobes located medially to origin of rictal barbels (Fig. 4 a). Lips with small papillae; papillae largest on inner surface of upper lip.
Barbels with large bases and tapering gradually towards tip. Nasal barbel origin on posterolateral portion of integument flap around anterior nostril. Nasal barbel long always surpassing pore i10, usually reaching to between pores of preopercularmandibular and pterotic branches. Two specimens with nasal barbel divided on tip. Maxillary barbel always extending to middle of interopercle, usually reaching pectoral-fin insertion.
Mesethmoid with anterior margin straight, cornua covering approximately one third of premaxilla. Anterior cranial fontanel drop-shaped situated between frontals; posterior cranial fontanel restricted to small rounded orifice situated posteriorly in parieto-supraoccipital (Fig. 2). Antorbital elongate with posterior tip almost reaching tendon-bone supraorbital. Tendon-bone supraorbital rod-shaped larger than antorbital. Anterior portion of sphenotic anteriorly directed from dorsal view. Sphenotic, prootic, and pterosphenoid totally fused. Vomer arrowshaped with long posterior process extending to parasphenoid. Parasphenoid with long pointed process extending to basioccipital. Anterior portion of Weberian complex fused to basioccipital. Weberian capsule with small lateral opening.
Premaxilla rectangular with 21–28 conical and pointed teeth (3) distributed with some irregularity in two rows.
Maxilla boomerang-shaped slightly shorter than premaxilla and with anteroventral process. Lower jaw with 31–32 conical, curved and pointed teeth variable in size (1). Teeth range from few teeth at base of coronoid process to three discernible rows near dentary symphysis. Autopalatine with anterior margin straight; mesial margin slightly concave in two specimens (42.5–49.5 mm SL) and notched in one specimen (66.2 mm SL); distal margin slightly concave; large posterior process (Figs. 2–5).
Metapterygoid laminar and connecting with quadrate through cartilage. Hyomandibula well-developed. Preopercle long, narrow, in contact with ventral margins of quadrate and hyomandibula. Opercular patch of odontodes rounded with 13–18 conical odontodes (3). Interopercular patch of odontodes elongate with 16–22 conical odontodes (3) more concentrated posteriorly. Odontodes of both opercular and interopercular patches gradually curving medially, increasing in size posteriorly.
Ventral hypohyal trapezoid-shaped. Anterior ceratohyal elongate, widening at anterior and posterior limits. Posterior ceratohyal notched posteriorly. Branchiostegal rays 7–8 (3) with fifth or sixth branchiostegal rays widest distally. Dorsal hypohyal and interhyal absent. Urohyal with expanded anterior head, bearing two elongate processes with wide bases narrowing distally and bearing pointed tips; posterior process pointed, short and laminar.
Basibranchial 1 absent. Basibranchials 2 and 3 connected to each other, of approximately equal lengths with cartilage at tips. Ossified portion of basibranchial 2 distinctly wider than basibranchial 3. Basibranchial 4 completely cartilaginous. Hypobranchial 1 of similar shape of basibranchial 2 with cartilage at tips. Hypobranchials 2 and 3 with narrow anterolateral ossified processes with large area of cartilage distally. Hypobranchial 4 absent. Five elongate, narrow ceratobranchials with cartilage at tips. Ceratobranchials 1, 2 and 3 with concavity along posterior margins; concavity largest in ceratobranchial 3. Ceratobranchial 5 expanded posteromedially with few conical, elongate, pointed teeth arranged in up to 3 rows. Five epibranchials, first three elongate and narrow with cartilage at tips. Epibranchials 1 and 2 with process along anterior margins; process elongate well developed in epibranchial 1. Epibranchial 3 with robust uncinate process along posterior margin. Epibranchial 4 rectangular. Epibranchial 5 small, narrow, curved, completely cartilaginous. Pharyngobranchials 1 and 2 absent. Pharyngobranchial 3 similar in form but shorter than basibranchial 3 with cartilage at tips. Pharyngobranchial 4 curved and well ossified connected to curved plate with few conical, curved and elongate teeth arranged in up to two rows; teeth increasing in length posteriorly.
Pectoral fin with distal margin rounded, one* (45) unbranched ray prolonged as short filament and 5 (3), 6* (41) or 7 (1) branched rays. Pelvic fin with distal margin rounded, reaching at most anterior margin of urogenital papilla, one* (44) unbranched ray and 3 (1) or 4*(43) branched rays. Inner margin of pelvic fins very close basally. Pelvic girdle with two basipterygia united medially by cartilage with two elongate bifid processes and medial process short. Pelvic splint thin, comma-shaped and parallel to first pelvic-fin ray. Urogenital papilla usually nearer tip of pelvic fin than origin of anal fin.
Dorsal fin with distal margin rounded, semicircular when fin expanded with three unsegmented rays (3), one (5), two* (39) or three (1) unbranched rays and 6 (5) or 7* (40) branched rays. Dorsal-fin origin located at vertical through tip of pelvic fin. Dorsal-fin basal radials 8 (3); first inserting anterior to neural spine of 24th (2) or 25th (1) vertebrae.
Anal fin approximately of same size of dorsal fin with distal margin straight to slightly rounded; three unsegmented rays (3), one (7) or two* (38) unbranched rays and 5* (36) or 6 (8) branched rays. Anal-fin origin located just posterior to dorsal-fin origin. Anal-fin basal radials 6 (3); first inserting anterior to haemal spine of 27th (3) vertebrae.
Caudal fin with distal margin straight or slightly rounded. Procurrent caudal-fin rays 14–16 dorsally and 12–13 ventrally (3) (Fig. 3). Caudal fin usually with one* unbranched ray externally in each caudal plate and 9 (1), 10 (2), 11* (39) or 12 (2) branched rays splitting two or three times. Lower caudal plate with parhypural and hypurals 1 and 2 co-ossified and fused to compound caudal centrum; upper caudal plate with separate uroneural; hypural 3 autogenous; hypurals 4 and 5 fused (Fig. 3).
Vertebrae 41 (1) or 42 (2); ribs 5 (1) or 6 (2); first rib straight and thickest; last rib rudimentary in specimens with six ribs. Anterior free vertebrae with parapophyses directed laterally. First complete haemal arch on seventh (2) or twelfth (1) free vertebrae. First complete haemal spine on 14th (1) or 15th (1) free vertebrae.
Sensory canals on head with simple (non-dendritic) tubes ending in single pore (Fig. 2). Supraorbital sensory canal interrupted between nasal and frontal branches; nasal and frontal branches with two pores (s1 and s2, s3 and s6, respectively). Infraorbital sensory canal divided in two isolated branches; anterior branch with pores i1 and i3 and posterior branch with pores i10 and i11. Postotic canal with preopercularmandibular and pterotic branches short and with one associated pore each. Lateral-line canal very short usually with 2 pores (rarely 3 pores) located above insertion of pectoral fin and just posterior of gill openings.
Coloration in alcohol. Dorsal and lateral surface of body with small dark brown blotches (equivalent to eye circumference) and numerous tiny dark brown dots over light brown background; dark pigmentation more concentrated dorsally; blotches larger near dorsal midline. Belly light yellow devoid of dark pigmentation; ventral surface of body between pelvic and anal fins and along caudal peduncle with very small dark brown dots. Dorsal surface of head dark brown or dark gray; cheek light brown with very small circular black dots visible in dorsal, lateral and ventral views; gular region light yellow, sometimes with scattered small black dots. Nasal and maxillary barbels dark brown pigmented on both dorsal and ventral surfaces; rictal barbel light yellow. Nasal and maxillary barbels with scattered circular dots along its length; usually arranged in two series near their bases and one series distally. Dorsal, caudal, pectoral and anal fins covered with small dark brown dots over light brown background in the caudal and dorsal fins and light yellow background in the pectoral and anal fins. Dots more concentrated in dorsal and caudal fins, becoming less numerous near the distal margin of dorsal fin. Pelvic fin light yellow without marks.
Distribution and ecological notes. Ituglanis boitata is endemic to the Tramandaí–Mampituba ecoregion sensu Abell et al. (2008). This area includes three small freshwater drainages (Fig. 6; the rio Araranguá, rio Mampituba and rio Tramandaí basins) draining from the “Serra Geral” into the coastal plain in Northeastern Rio Grande do Sul and Southeastern Santa Catarina States, southern Brazil. The rio Araranguá and rio Mampituba flows directly into the sea while the rio Tramandaí basin is composed by two main rivers draining the Serra Geral (the rio Três Forquilhas and rio Maquiné) that flows to two large lagoons in the coastal plain. These lagoons are interconnected with a series of smaller lagoons, all flowing to the sea through an estuary known as rio Tramandaí. Ituglanis boitata is usually found associated with clear water, rocky bottom, and small currents streams and rivers in the middle and upper portions of these drainages (Fig. 7) and has never been collected in lagoons or surroundings swamps of the coastal plain.
An area of fish endemism including the rio Maquiné, rio Três Forquilhas and rio Mampituba basins was first mentioned by Malabarba & Isaia (1992). Later, Reis & Schaefer (1999) expanded this area to include the rio Araranguá basin, coinciding with the area latter referred as Tramandaí–Mampituba ecoregion sensu Abell et al. (2008). Bertaco & Malabarba (2013) have recently listed five species of Characidae and some representatives of Loricariidae as endemic to the Tramandaí–Mampituba ecoregion, but we found at least 23 species endemic to this area including recent species descriptions (Bertaco 2014; Reis et al. 2014) and Ituglanis boitata (Table 2).
Etymology. From the indigenous language Tupi-Guarani “boi” (snake) and “tata” (fire) in reference to the orangish coloration and to the species swimming behavior that resembles a snake. “ Boitata ” snake is part of several fictitious tales in the Brazilian culture popularized in the Rio Grande do Sul State by the writer Simões Lopes Neto.
Remarks. Even though the external aspect of Ituglanis boitata and I. proops are very similar, some differences are readily remarkable. These species differ in the number of branched dorsal-fin rays—modally seven in I. boitata (observed in 40 of 45 analyzed specimens) vs. modally six in I. proops (observed in 23 of 24 analyzed specimens); and in the interopercular patch of odontodes length (Fig. 4; 22.7–31.4 vs. 35.2–43.1 mm of HL, respectively). De Pinna & Keith (2003) have already highlighted the large interopercular plate in I proops as “the largest interopercular patch of odontodes in the genus” and stated that “(…) the dorsoposterior margin of the interopercular patch closely approaches the ventral margin of the opercular one”. Subsequently, the unusual interopercular patch of I proops was illustrated and cited as “clearly more elongate than those of many other trichomycterines” by Datovo & Bockmann (2010: fig. 38a).
description: Published as part of Ferrer, Juliano, Donin, Laura M. & Malabarba, Luiz R., 2015, A new species of Ituglanis Costa & Bockmann, 1993 (Siluriformes: Trichomycteridae) endemic to the Tramandaí – Mampituba ecoregion, southern Brazil, pp. 375-389 in Zootaxa 4020 (2) on pages 376-384, DOI: 10.11646/zootaxa.4020.2.8, http://zenodo.org/record/236516