Farlowella wuyjugu, Dopazo & Wosiacki & Britto, 2023

Dopazo, Manuela, Wosiacki, Wolmar B. & Britto, Marcelo R., 2023, New species of Farlowella (Siluriformes: Loricariidae) from the rio Tapajós basin, Pará, Brazil, Neotropical Ichthyology (e 220097) 21 (1), pp. 1-17 : 4-11

Farlowella wuyjugu , new species urn:lsid:zoobank.org:act:FA22FB00-B26F-45C0-A121-2BD8FB00B523

( Figs. 2–3 ; Tab. 1)

Holotype. MPEG 26178, 143.4 mm SL, Brazil, Pará State , Juruti municipality, lower rio Tapajós , rio Amazon basin, igarapé Rio Branco, 02°20’58.6”S 56°01’26.4”W, 27 Nov 2012, M. B. Mendonça.

Paratypes. All from Brazil, Pará State , Juruti municipality, rio Arapiuns basin, lower rio Tapajós , rio Amazon basin. INPA 59894 , 2 , 124.8 – 128.9 mm SL, igarapé Mutum , affluent of rio Aruã, tributary of Rio Branco, 02°36’44.5”S 56°11’37.3”W, 8 Sep 2002, W. B. Wosiacki. MNRJ 53691 , 2 , 127.3 – 130.9 mm SL, same locality as INPA 59894. MPEG 10062 , 5 , 112.0– 121.6 mm SL, same locality as INPA 59894, 3 Mar 2006, L. F. A. Montag. MPEG 12865 , 5 , 90.9–123.2 mm SL, same locality as INPA 59894, 11 Dec 2006, L. F. A. Montag & A. Hercos. MPEG 15900 , 12 , 2 cs, 97.6–136.5 mm SL, same locality as INPA 59894, 8 Sep 2002, W. B. Wosiacki. MPEG 10857 , 5 , 111.7 – 128.2 mm SL, igarapé São Francisco, 02°34’52”S 55°54’10.8”W, 19 Aug 2006, A. Hercos. MPEG 32191 , 4 , 94.3–133.9 mm SL, same locality as MPEG 10857, 14 Sep 2014, M. B. Mendonça. MPEG 12684 , 5 , 1 cs, 122.8–144.7 mm SL, igarapé São Francisco, 02°34’50.7”S 55°50’13.8”W, 14 Dec 2006, L. F. A. Montag .

Non-types. All from Brazil, Pará State , Juruti municipality, rio Arapiuns basin, lower rio Tapajós , rio Amazon basin. MPEG 10055 , 4 , 102.9 – 124.3 mm SL, MPEG 10062 , 13 , 70.0– 109.7 mm SL, igarapé Mutum , affluent of rio Aruã , tributary of Rio Branco , 02º36’44.5”S 56º11’37.3”W, 3 Mar 2006, L. F. A. Montag. MPEG 10851 , 1, 119.2 mm SL, MPEG 10852 , 3 , 79.5–116.1 mm SL, MPEG 10853 , 1, 121.9 mm SL, igarapé São Francisco, 02°34’50.7”S 55°54’13.8”W, 19 Aug 2006, A. Hercos. MPEG 10855 , 4 , 46.7–88.7 mm SL, MPEG 10856 , 7 , 54.2–108.4 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’44.5”S 56°11’35.5”W, 17 Aug 2006, A. Hercos. MPEG 10857 , 11 , 65.1–145.8 mm SL, MPEG 10858 , 2 , 106.2 – 112.8 mm SL, MPEG 10859 , 4 , 64.4–128.3 mm SL, MPEG 10861 , 1, 113.7 mm SL, igarapé São Francisco, 02°34’50.7”S 55°54’13.8”W, 19 Aug 2006, A. Hercos. MPEG 10860 , 1, 128.6 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’44.5”S 56°11’35.5”W, 17 Aug 2006, A. Hercos. MPEG 10862 , 3 , 49.6–54.6 mm SL, igarapé São Francisco, 02°34’50.7”S 55°54’13.8”W, 19 Aug 2006, A. Hercos. MPEG 10956 , 1 , 26.2 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of rio Branco , 02°36’44.5”S 56°11’35.5”W, 17 Aug 2006, A. Hercos. MPEG 12491 , 4 , 18.6–45.8 mm SL, igarapé Mutum, 02°36’44.8”S 56°11’37.3”W, 9 Sep 2002, W. B. Wosiacki. MPEG 12865 , 4 , 69.8–93.4 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02º36’44.5”S 56º11’37.3”W, 11 Dec 2006, L. F. A. Montag & A. Hercos. MPEG 13040 , 2 , 35.7–38.4 mm SL, MPEG 13043 , 2 , 20.6–30 mm SL, MPEG 13050 , 2 , 11.0– 118.4 mm SL, igarapé São Francisco, 02°34’50.7”S 55°54’13.8”W, 19 Aug 2006, L. F. A. Montag. MPEG 13041 , 1 , 56.3 mm SL, MPEG 13044 , 5 , 56.8–93.2 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’44.5”S 56°11’35.5”W, 12 Dec 2006, L. F. A. Montag. MPEG 13042 , 3 , 48.1 – 45.5 mm SL, igarapé São Francisco, 02°34’50.7”S 55°54’13.8”W, 14 Dec 2006, L. F. A. Montag. MPEG 13045 , 1 , 92.7 mm SL, igarapé São Francisco, 02°34’50.7”S 55°54’13.8”W, 14 Dec 2006, L. F. A. Montag. MPEG 13046 , 1, 101.7 mm SL, igarapé São Francisco, 02°34’50.7”S 55°54’13.8”W, 15 Dec 2006, L. F. A. Montag. MPEG 13048 , 5 , 50.2–80.8 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’44.5”S 56°11’35.5”W, 11 Dec 2006, L. F. A. Montag. MPEG 13731 , 2 , 63.9–69.4 mm SL, MPEG 14143 , 7 , 61.9–136.5 mm SL, igarapé São Francisco, 02°34’50.7”S 55°54’13.8”W, 15 May 2007, A. Hercos. MPEG 14271 , 1 , 42.8 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’44.5”S 56°11’35.5”W, 27 Nov 2007, A. Hercos. MPEG 14711 , 13 , 46.2–126.3 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’44.5”S 56°11’35.5”W, 11 May 2007, A. Hercos. MPEG 15900 , 8 , 56.6–95.8 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’44.5”S 56°11’37.3”W, 8 Sep 2002, W. B. Wosiacki. MPEG 16955 , 1, 120.7 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’33.2”S 56°11’33.4”W, 19 Feb 2008, W. B. Wosiacki. MPEG 26172 , 13 , 71.8–129.8 mm SL, MPEG 26173 , 4 , 61.5–94.5 mm SL, MPEG 26333 , 1 , 86.4 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’45.8”S 56°11’36.8”W, 28 Nov 2012, M. B. Mendonça. MPEG 26179 , 19 , 43.5–156.4 mm SL, igarapé Rio Branco , 02°20’58.6”S 56°01’26.4”W, 27 Nov 2012, M. B. Mendonça. MPEG 29996 , 2 , 112.7 – 117.4 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’45.8”S 56°11’36.8”W, 6 Dec 2013, M. B. Mendonça. MPEG 26997 , 9 , 100.5 – 129.9 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’45.8”S 56°11’36.8”W, 7 Dec 2013, M. B. Mendonça. MPEG 26998 , 1 , 88.9 mm SL, igarapé São Francisco, 02°34’52”S 55°54’10.8”W, 11 Dec 2013, M. B. Mendonça. MPEG 26999 , 5 , 51.9–138.1 mm SL, igarapé Rio Branco , 02°20’58.6”S 56°01’26.4”W, 12 Dec 2012, M. B. Mendonça. MPEG 32191 , 4 , 93.7– 136.6 mm SL, MPEG 32192 , 2 , 55.6–115.1 mm SL, igarapé São Francisco, 02°34’52”S 55°54’10.8”W, 19 Sep 2014, M. B. Mendonça. MPEG 32193 , 15 , 32.9–124.2 mm SL, MPEG 32194 , 14 , 61.4–127.3 mm SL, igarapé Mutum, affluent of rio Aruã , tributary of Rio Branco , 02°36’45.8”S 56°11’36.8”W, 22 Sep 2014, M. B. Mendonça. MPEG 32195 , 1, 135.1 mm SL, igarapé Rio Branco , 02°20’58.6”S 56°01’26.4”W, 18 Sep 2014, M. B. Mendonça. MPEG 32507 , 72.4–113.1 mm S, MPEG 32508 , 11 , 49.0– 116.5 mm SL, igarapé Mutum, affluent of rio Aruã, tributary of Rio Branco, 02°36’45.8”S 56°11’36.8”W, 20 Mar 2015, M. B. Mendonça .

Diagnosis. Farlowella wuyjugu can be diagnosed from its congeners by lack of plates in gular region (vs. gular plates present) ( Fig. 3 ). The new species can be distinguished from its congeners, except Farlowella altocorpus Retzer, 2006 , F. azpelicuetae Terán, Ballen, Alonso, Aguilera & Mirande, 2019 , F. gianetii Ballen, Pastana & Peixoto, 2016 , F. gracilis Regan, 1904 , F. guarani Delgadillo, Maldonado & Carvajal-Vallejos, 2021 , F. hasemani Eigenmann & Vance, 1917 , F. isbrueckeri Retzer & Page, 1997 , F. jauruensis Eigenmann & Vance, 1917 , F. myriodon , F. nattereri Steindachner, 1910 , and F. odontotumulus Retzer & Page, 1997 , by having five lateral series of plate rows on anterior region of body (vs. four). Additionally, F. wuyjugu differs from F. altocorpu s and F. azpelicuatae by having a smaller body width at dorsal origin (4.3–5.5 vs. 6.4–8.1% SL); from F. gianetti by number of caudal-fin rays (i,11,i or i,12,i vs. i,10,i); from F. gracilis by having head triangular in dorsal view (vs. head square); from F. guarani by interorbital width (12.0–16.0 vs. 28.6– 44% HL) and eye diameter (3.6–5.8 vs. 6.6–13.3% HL); from F. hasemani by all fin rays uniformly pigmented (vs. fin rays not pigmented); from F. isbruckeri and F. odontotumulus by having the ventromedian row of anterior plates keeled (vs. ventromedian row of anterior plates unkeeled); from F. jauruensis by having five branched pelvic-fin rays (vs. four branched pelvic-fin rays); from F. myriodon by having dark brown lateral stripe on each side of snout (vs. absence of such stripe, snout completely dark); and from F. nattereri by having a short pectoral fin, not reaching the pelvic-fin base (vs. long pectoral fin, reaching the pelvic-fin base).

Description. Dorsal, lateral, and ventral views of holotype in Fig. 2 . Morphometric and meristic data for holotype and paratypes summarized in Tab. 1. Body slender and very elongated, completely covered by dermal plates, except in gular portion. Head triangular and elongate in dorsal and ventral views. Rostrum slender and flat in ventral view. Orbit circular, dorsolaterally placed, visible in dorsal view and not visible in ventral view. Preorbital ridge present. Mouth ventral. Dorsal profile of head concave from snout tip to anterior margin of nares, relatively straight to convex from point to posterior margin of nares to posterior margin of parieto-supraoccipital and slightly concave to dorsal-fin origin. Posterior profile of margin of dorsal-fin origin slightly concave and straight profile to end of caudal peduncle. Ventral profile slightly straight from tip of snout to anal-fin origin, slightly concave in anal-fin base and straight profile to end of caudal peduncle.

Mouth ovoid, lower lip longer than upper lip; wide oval papillae on upper lip and round papillae on lower lip, decreasing in size from oral aperture to lip margin; lip margin papillose. Bicuspid slender teeth, each premaxilla with 22(2), 23*(1), 29(1), 31(1), 33(1), 36(1), 37(3), 39(1), 40(2), 41(1), 42(3), 43(2), 44(1), 46(3), 47(4), 48(4), 49(4), 51(2), 53(1) or 55(1) teeth and each dentary with 18*(3), 22(1), 23(1), 26(2), 28(1), 29(2), 30(2), 32(3), 33(3), 34(1), 35(4), 36(3), 37(1), 38(4), 39(2), 40(2), 41(1), 42(1) or 43(2) teeth; premaxilla larger than dentary. Two maxillary barbels small and projecting slightly from mouth margin.

Five lateral plate rows on body, with 31(6), 32*(30) or 33(3) dorsal plates; 6(1), 7*(5), 8(23) or 9(10) dorsomedian plates; 7(1), 8*(5), 9(20) or 10(13) median plates; 14*(7), 15(27) or 16(5) ventromedian plates; 35(3), 36(7), 37*(15), 38(9), 39(3) or 40(2) ventral plates; 5(14), 6*(18), 7(6) or 8(1) dorsomedian+median plates; 18(12), 19(20) or 20*(7) coalescent plates; 8*(39) predorsal plates; 23(6), 24*(30) or 25(3) postdorsal plates; 20(2), 21(14), 22*(21), 23(1) or 24(1) postanal plates; 2 plates at the base of caudal fin and one preanal plate. Abdomen covered with two lateral rows with 6(6), 7*(19), 8(11), 9(2), 11(1) lateral abdominal plates (left) and 6(10), 7*(14), 8(8) or 9(7) lateral abdominal plates (right), and one midabdominal incomplete (23)* row or when complete (16) row with 2(1), 3(2), 4*(2), 5(1), 6(5), 7(7), 8(7), 9(3), 10(3), 11(2), 12(3), 13(2) or 16(1) midabdominal plates.

Lateral line complete; reaching up to last caudal peduncle coalesced plate. Preopercular canal passing through infraorbital six with two pores. Terminal exit of parietal branch in frontal bone curved. Canal-bearing cheek plate in ventral position. Nasal slightly curved in anterior portion with pore opening laterally.

Pectoral-fin rays i,6*(39); posterior margin slightly concave; unbranched ray longest. Dorsal-fin rays i,6*(39); posterior margin straight to slightly concave; three* or four plates along its base; unbranched ray longest. Pelvic-fin rays i,5*(39); posterior margin straight; unbranched ray longest. Anal-fin rays i,5*(39); posterior margin straight to slightly concave; unbranched ray longest; three* or four plates along its base. Caudal-fin rays i,11,i(2) or i,12,i*(37); posterior margin deeply concave; dorsal and ventral lobes similar in size; filaments on upper and lower unbranched rays. All fin rays with odontodes; more developed odontodes on unbranched first ray.

Mesethmoid long; lateral expansion of anterior portion absent; mesethmoid ventral posterior process present. Nasal rectangular irregular bone curved laterally. Frontal wide, occluded from dorsal border of orbit. Orbit anteriorly delimited by dermal plate, dorsally by frontal bone, dorsolaterally by sphenotic, and ventrally by infraorbital series. Sphenotic quadrate in shape, contacting frontal bone anterolaterally, parieto-supraoccipital dorsally, infraorbital six ventrally, and pterotic-extrascapular posteriorly. Pterotic-extrascapular with large perforations. Parieto-supraoccipital wide and oval, contacting first predorsal plate posteriorly. Anterior contact of hyomandibula with metapterygoid and quadrate, and ventral with preopercle. Symphyseal cartilage between quadrate and hyomandibula. Anterior margin of quadrate articulation with anguloarticular. Dentary almost twice the size of anguloarticular. Autopalatine irregular, rod-like shape. Anterior margin of autopalatine articulation with maxilla and posterior contact posteriorly with vomer and metapterygoid. Preopercle long and partially exposed; anterior process reaching at least half of quadrate length. Suspensorium rectangular in overall shape. Three branchiostegal rays. Hypohyal anterior border straight, without anterior projection. Urohyal triangular and posterior margin rounded, with medial foramen. Anterohyal and posterohyal partially separated by cartilage. Anterior margin of anterohyal greatly expanded. Basibranchial 2, 3 and 4 present; basibranchial 2 and 3 elongated; basibranchial 2 equal to basibranchial 3; basibranchial 2 and 3 ossified and basibranchial 4 cartilaginous. Two hypobranchials; hypobranchial 1 ossified and hypobranchial 2 cartilaginous. Four epibranchials with similar size. Five ceratobranchials; ceratobranchial 1 with accessory flange; ceratobranchial 5 triangular; ceratobranchial teeth restricted to mesial area of plate. Upper pharyngeal plate clubshaped, completely covered with fine teeth. Vertebral count 39(1) and 40(1); five thin pleural ribs directly attached to centra 8, 9, 10, 11 and 12(1) and four thin pleural ribs directly attached to centra 9, 10, 11 and 12(1); parapophysis of complex vertebra well developed (two specimens).

Coloration in alcohol. Ground color of dorsum and head pale or dark brown. Light brown color with diffuse and scattered dark brown spots on predorsal portion, from tip of parieto-supraoccipital and extending to all plates. Five to six rounded spots between the second and third infraorbital, extending to opercle. One dark brown lateral stripe on each side, that runs from snout to caudal peduncle. Ventral portion of head brown; yellow between lower lip and anterior portion of anal fin. Dorsal profile in posterior portion of anal fin light brown with diffuse and scattered dark brown spots along the plates, same to dorsal portion, more delimited in some individuals. Upper lip with scattered chromatophores. Pectoral, dorsal, pelvic, and anal fin rays with hyaline membranes and pigmented brown rays, sometimes forming dark bands. First rays markedly dark. Caudal fin almost completely dark brown, membranes and rays pigmented, in some individuals with area of hyaline membrane ( Fig. 4 ).

Geographical distribution. Farlowella wuyjugu is known only from small, forest creeks near Juruti, Pará State, tributaries of rio Arapiuns, rio Tapajós in its lower portion, rio Amazon basin, Brazil ( Fig. 5 ).

Etymology. The specific epithet refers to the combination of the words Wuy jugu, which is the self-denomination of indigenous people known in Brazil as Munduruku. This ethnic group is part of the Tupi trunk and they are located in different regions and territories in the states of Pará, Amazonas, and Mato Grosso. In the region of the lower Tapajós River, in recent years some communities in the process of their ethnic identity have recognized themselves as Munduruku ( Ramos, 2022). A noun in apposittion.

Conservation status. Farlowella wuyjugu is known from four collection stations [igarapé Rio Branco ( Fig. 6 ), igarapé Mutum, and igarapé São Francisco] in Juruti municipality, Pará State, Brazil. Using the GeoCAT we calculate the extent of occurrence (EOO) of the species in 4,921 km 2, suggesting a threatened category of Endangered (EN). Farlowella wuyjugu is sampled in few localities in the Juruti municipality, impacted by a large bauxite extraction project, deteriorating their habitats. Following the recommendations by the IUCN (IUCN Standards and Petitions Committee, 2022), F. wuyjugu should be categorized as Nearly Threatened (NT), following criterions B2:EN (EOO <5,000 km 2), b(iii) (decline of quality of habitat by bauxite extraction).

Variation of abdominal plates within Farlowella wuyjugu . Abdominal plates are usually termed as lateral abdominal plates, which are transversely elongated plates between the pectoral-fin axilla and the pelvic-fin insertion, and midabdominal plates, which cover the abdomen between the lateral ones ( Londoño-Burbano, Reis, 2021). The midabdominal plates, in Farlowella , can be absent or present and when present can be incomplete or complete. Ballen et al. (2016b) described Falowella mitoupibo Ballen, Urbano-Bonilla & Zamudio, 2016 and proposed as diagnostic for the species an incomplete median disjunct row of abdominal plates, divided at the center by plates belonging to the lateral rows of abdominal plates (vs. two or three complete rows of abdominal plates or an incomplete median row of one or two plates anteriorly that never reach to the level of the prepelvic plate). Although the authors proposed this character as a diagnosis for the species, in recent examinations of the type material of F. mitoupibo , it was possible to observe two completes rows of abdominal plates in one specimen (M. Dopazo, pers. obs.). Farlowella wuyjugu have midabdominal plates and can be an incomplete or complete midabdominal series ( Fig. 3 ). An incomplete midabdominal series can be a disjunct row as described for F. mitoupibo or an incomplete median row of plates anteriorly that do not reach to the level of the prepelvic plate ( Figs. 3A, B ). Retzer, Page (1996) proposed the number of rows of abdominal plates as a diagnostic character to differentiate species group of Farlowella : two rows ( F. acus ( Kner, 1853) group and F. amazonum Günther, 1864 group) and three rows ( F. curtirostra Myers, 1942 group, F. mariaelene Martín Salazar, 1964 group, F. nattereri group, F. knerii (Steindachner, 1882) group and unassigned species group). Although Retzer, Page (1996) proposed the number of rows of abdominal plates as a diagnostic character to differentiate species groups of Farlowella , both states were found in F. wuyjugu and F. mitoupibo , rendering that character not be useful to differentiate groups because they are variable within Farlowella species. A phylogenetic analysis of the genus (including the species described here) is being carried out and aims to test if these characters (proposed by Retzer, Page, 1996) are in fact phylogenetically informative.

Figures

FIGURE 2 | Dorsal, lateral and ventral view of Farlowella wuyjugu, holotype, 143.4 mm SL, MPEG 26178, Brazil, Pará State, Juruti municipality, igarapé Rio Branco, lower rio Tapajós, rio Amazon basin.

FIGURE 3 | Gular region and variation of abdominal plates in specimens, ventral view of Farlowella wuyjugu. A. MPEG 26178, 143.4 mm SL; B. INPA 59894, 128.9 mm SL; C. MPEG 12684, 125 mm SL.

FIGURE 4 | Caudal fin coloration of Farlowella wuyjugu. MPEG 31191, 119.9 mm SL.

FIGURE 5 | Geographic distribution of Farlowella wuyjugu in lower rio Tapajós. Star = holotype; circles = paratypes localities.

FIGURE 6 | Igarapé Rio Branco, type-locality of Farlowella wuyjugu.