Eigenmannia pavulagem, Peixoto & Dutra & Wosiacki, 2015

Peixoto, Luiz Antônio Wanderley, Dutra, Guilherme Moreira & Wosiacki, Wolmar Benjamin, 2015, The Electric Glass Knifefishes of the Eigenmannia trilineata species-group (Gymnotiformes: Sternopygidae): monophyly and description of seven new species, Zoological Journal of the Linnean Society 175 (2), pp. 384-414 : 403-405

EIGENMANNIA PAVULAGEM SP. NOV.

( FIGS 17 , 18 ; TABLE 3)

Eigenmannia gr. trilineata, Vari et al., 2012: 697 (comparative material).

Diagnosis: Eigenmannia pavulagem can be distinguished from other species in the E. trilineata species group, except E. guairaca and E. microstoma , by the pattern of premaxillary dentition with 13–16 teeth distributed in three rows (outer row with three to five teeth; middle row with five to six; inner row with four to six) [versus eight to 12 teeth distributed in two rows [outer row with 3–6 teeth; inner row with 4–6 teeth] in E. antonioi ; 24 or 25 teeth distributed in four rows [outermost row with 5 teeth; second row with 6–8 teeth; third row with 6 or 7 teeth; innermost row with 7 or 8 teeth] in E. desantanai ; 22–24 teeth distributed in four rows (outermost row with three or four teeth; second row with five or six teeth; third row with seven teeth; innermost with six to eight teeth) in E. matintapereira ; eight to ten teeth distributed in two rows (outer row with three to five teeth; inner row with four to six teeth) in E. muirapinima ; 31–33 teeth distributed in four rows (outermost row with eight or nine teeth; second row with five or six; third row with ten; innermost row with seven to nine teeth) in E. trilineata ; 25–26 teeth distributed in four rows (outermost with five or six teeth; second row with four to seven teeth; third row with seven or eight teeth; innermost row with five to nine teeth) in E. vicentespelaea ; and 35–40 teeth distributed in five rows (outermost row with seven to eight teeth; second row with seven or eight teeth; third row with eight or nine teeth; fourth row with seven to nine teeth; innermost row with six teeth) in E. waiwai ]. Eigenmannia pavulagem can be distinguished from E. guairaca by the ii,13–14 pectoral-fin rays (versus ii,11–12), and by the number of total analfin rays 176–201 (versus 151–170). Eigenmannia pavulagem can be differentiated from E. microstoma by the suborbital depth 19.4–27.4% HL (versus 29.9– 40.8%); the length of anterodorsal process of maxilla equal to 50% the width of the posterior nostril (versus equal to the width of the posterior nostril); and the coronomeckelian bone length equal to 20% the length of Meckel’s cartilage (versus 45% the length of Meckel’s cartilage).

Description: Morphometric data are presented in Table 3. Body elongate and laterally compressed. Dorsal profile of body nearly straight from rear of head to vertical through middle of anal fin, and then posteroventrally aligned with distal portion of caudal filament. Ventral profile of body slightly concave along anterior half of abdominal cavity, then posterodorsally aligned with last anal-fin ray. Ventral margin of caudal filament straight. Greatest body depth at vertical through distal margin of pectoral fin.

Head laterally compressed, with greatest width at opercular region and greatest depth at posterior margin of supraoccipital. Dorsal profile of head slightly convex from upper lip to vertical through branchial opening. Ventral profile of head slightly concave from anterior margin of lower lip to branchial opening. Snout rounded in profile. Mouth terminal. Upper lip slightly overlapping lower lip. Premaxillary teeth, 13(1), 14(1), 15(2), or 16(1), distributed in three rows [outermost row with 3(2), 4(2), or 5(1) teeth; median row with 5(1) or 6(4) teeth; innermost row with 4(2), 5(1), or 6(2) teeth]. Maxilla with sickle-shaped anterodorsal process equal to 50% of width of posterior nostril. Dentary teeth 15(1), 17(1), 20(2), or 21(1), distributed in two rows [outer row 11(1), 12(3), or 16(1) teeth; inner row with 4(1), 5(2), or 8(2) teeth]. Dentary teeth increasing abruptly in size from seventh, ninth, or tenth teeth of outer row towards rictus. Coronomeckelian bone equal to 20% of length Meckel’s cartilage. Endopterygoid with 8(1), 9(1), 10(2), or 11(1) teeth in one or two rows. Mouth rictus at vertical through anterior nostril or in region between nares. Anterior naris tube-like, with posteri- or margin located at vertical through posterior margin of, or in median portion of, rictus. Posterior naris elliptical, without tube, located closer to anterior margin of eye than snout tip. Eye approximately circular, covered by skin, laterally located on anterior half of head. Antorbital and infraorbitals 1–4 in form of enlarged, partial cylinders with slender osseous arches. Fifth and sixth infraorbitals slender and tubular. Depth of posterodorsal expansion on infraorbitals 1 + 2 equals total length of infraorbitals 1 + 2. Branchial opening moderately elongate. Branchial membrane joined to isthmus. Anus and urogenital papilla shifting anteriorly ontogenetically and at vertical through posterior margin of orbit in mature specimens.

Cycloid scales present from immediately posterior to head to distal portion of caudal filament. Lateral line complete with 120(1), 121(2), 125(1), 126(1), 127(1), 128(1), 129(4), 130(1), 131(1), 132(3), 133(2), 134 (1), 135(2), 136(1), 137*(3), 138(1), 139(2), 140(2), 144(1), or 146(1) perforated scales to vertical through end of anal fin. Longitudinal series of scales above lateral line, 8(11), 9*(12), 10(6), 11(3), or 12(2). Scales over analfin pterygiophores approximately one-half the size of others.

Pectoral-fin rays, ii,13*(16) or ii,14(22). Distal margin of fin slightly rounded. Tip of pectoral fin reaching vertical through base of anal-fin rays 14–18. Anal-fin origin immediately posterior to vertical through pectoral-fin base; total anal-fin rays, 176–201 (192*, N = 38; Table 2). Distal margin of anal fin approximately concave. Caudal filament cylindrical, tapering gradually distally, relatively long and approximately 50% of LEA in mature specimens.

Precaudal vertebrae, 13(1), 14(3), or 15(1). Anteri- or vertebrae, 10(1), 11(3), or 13(1); transitional vertebrae, 1(1), 3(3) or 4(1). Displaced haemal spines, 3(5).

Coloration in alcohol: Background colour dark yellow. Dorsal region of head darkened; gradually becoming lighter ventrally. Lips and suborbital region clear yellow. Dorsal region of body yellowish, gradually lighter in region overlying anal-fin ray pterygiophores. Four longitudinal dark stripes along body. Lateral-line stripe thin, one scale deep, extending from first perforated lateral-line scale to distal portion of caudal filament.

EIGENMANNIA TRILINEATA SPECIES-GROUP 405

Superior medial stripe thick, two scales deep, tapering from vertical between base of anal-fin rays 25–30 to posterior one-third of body. Inferior medial stripe moderately thick, two scales deep, extending from vertical between base of anal-fin rays 14–30 to posterior one-third of body. Anal-fin base stripe thick, two scales deep, extending from vertical between base of analfin rays 10–20 to last anal-fin ray. Pectoral and anal fins hyaline, with scattered tiny chromatophores on interradial membranes.

Distribution: Eigenmannia pavulagem sp. nov. is known from small tributaries of the Rio Capim, Rio Guamá basin, north-eastern Pará, Brazil ( Fig. 6 ).

Etymology: The epithet ‘ pavulagem ’ is a tribute to the cultural movement created in the state of Pará, ‘Arraial do Pavulagem’, characterized by music of a unique traditional style that originated in Amazon region.

Material examined

Holotype: Brazil. Pará: MPEG 6887, 176.6 mm LEA, Igarapé Paraquequara, tributary of Rio Capim, Rio Guamá basin, Município de Paragominas , 3°14′50″ S, 47°45′50″ W, collected by A. Souza, 16 April 2003.

Paratypes: Brazil. Pará: MPEG 7307 , 2 , 120.8 – 133.1 mm LEA, Igarapé Paraquequara, tributary of Rio Capim, Rio Guamá basin, 3°16′05″ S, 47°46′05″ W, collected by A. Souza, 13 December 2002 . MPEG 7308 , 6 , 63.1– 94.9 mm LEA, Igarapé Paraquequara, tributary of Rio Capim, Rio Guamá basin, 3°16′05″ S, 47°46′05″ W, collected by V. Sena, 13 December 2002 . MPEG 9524 , 3 CS, 90.7–108.5 mm LEA, Igarapé Anuera-Grande, tributary of Rio Capim, Rio Guamá basin, 2°30′2.9″ S, 48°16′52.6″ W, collected by A. Souza, 30 June 2005 . MPEG 9535 , 10 , 42.6–102.7 mm LEA, Igarapé Arrainha, tributary of Rio Capim, Rio Guamá basin, 02°25′11.1″ S, 48°12′13.1″ W, collected by L. Montag, 1 July 2005 . MPEG 29490 , 17 , 26.2–176.6 mm LEA; MZUSP 116797 , 2 , 118.4 – 152.8 mm LEA, collected with the holotype ; INPA 46984 , 2 , 90.2–113.4 mm LEA, collected with holotype. NUP 17104, 2, 82.7–114.7 mm LEA, collect- ed with holotype.

Figures

Figure 6. Map of South America showing the distribution of Eigenmannia antoinoi sp. nov., Eigenmannia desantanai sp. nov., Eigenmannia guairaca sp. nov. sp. nov., Eigenmannia matintapereira sp. nov., Eigenmannia microstoma (1 = type locality), Eigenmannia muirapinima sp. nov., Eigenmannia pavulagem sp. nov. (2 = type locality), Eigenmannia trilineata (3 = type locality), Eigenmannia vicentespelaea, and Eigenmannia waiwai sp. nov. Some symbols represent more than one lot and/or locality.

Figure 17. Lateral view of Eigenmannia pavulagem sp. nov., holotype, MPEG 6887, 176.6 mm LEA, Igarapé Paraquequara, Rio Capim, Rio Guamá basin, Município de Paragominas, Pará, Brazil, 3°14′50″ S, 47°45′50″ W.

Figure 18. Lateral view of head of Eigenmannia pavulagem sp. nov., holotype, MPEG 6887, 176.6 mm LEA, Igarapé Paraquequara, Rio Capim, Rio Guamá basin, Município de Paragominas, Pará, Brazil, 3°14′50″ S, 47°45′50″ W.