Eigenmannia waiwai, 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 : 410-412

EIGENMANNIA WAIWAI SP. NOV.

( FIGS 23 , 24 ; TABLE 4)

Eigenmannia virescens, Ferreira, 1993: 51 (cheklist).

Diagnosis: Eigenmannia waiwai can be distinguished from other species in the E. trilineata species group by the length of anterodorsal process of maxilla equal to 1.5 times the width of the posterior nostril (versus equal to 50% of the width of posterior nostril in E. antonioi , E. desantanai , E. guairaca , E. muirapinima , E. pavulagem , and E. vicentespelaea , or equal to the width of the posterior nostril in E. matintapereira , E. microstoma , and E. trilineata ; Fig. 4 ). Eigenmannia waiwai also differs from species of the E. trilineata species group, except E. vicentespelaea , by the subterminal mouth (versus terminal mouth). Eigenmannia waiwai sp. nov. can be distinguished from E. vicentespelaea by the nine or ten longitudinal series of scales above the lateral line (versus seven or eight); body depth at the vertical through the tip of longest pectoral-fin ray, 14.9–18.7% LEA (versus 10.5–14.5%); depth of the posterodorsal expansion on infraorbitals 1 + 2 less than 50% of length of infraorbitals 1 + 2 (versus approximately equal to length of infraorbitals 1 + 2); and length of the coronomeckelian bone equal to 20% of the length of Meckel’s cartilage (versus 45% of the length of Meckel’s cartilage).

Description: Morphometric data are presented in Table 4. 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 posteroventrally aligned from anterior margin of lower lip to anal-fin rays 10–20, nearly 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 subterminal. Upper lip overlapping lower lip. Premaxillary teeth, 35(1) or 40(1), distributed in five rows [outermost row with 7(1) or 8(1) teeth; second row with 7(1) or 8(1) teeth; third row with 8(1) or 9(1) teeth; fourth row with 7(1) or 9(1) teeth; innermost row with 6(2) teeth]. Maxilla with sickleshaped anterodorsal process equal to 1.5 times width of posterior nostril. Dentary teeth 37(1) or 38(1), distributed in four rows [outermost row with 7(2) teeth; second row with 11(1) or 15(1) teeth; third row with 8(1) or 15(1) teeth; innermost row with 4(1) or 8(1) teeth]. Dentary teeth similar in size. Coronomeckelian bone equal to 20% of length of Meckel’s cartilage. Endopterygoid with 14(1) or 17(1) teeth, distributed in two rows. Mouth rictus at vertical through anterior nostril or in region between nares. Anterior naris tube-like, with posterior 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 less than 50% of length of infraorbitals 1 + 2. Branchial opening moderately elon- gate. Branchial membrane joined to isthmus. Anus and urogenital papilla shifting anteriorly ontogenetically, 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 112(3), 113(3), 114(4), 115(5), 118(2), 122(3), 123(2), 127(1), or 128*(3) perforated scales to vertical through end of anal fin. Longitudinal series of scales above lateral line, 9(4) or 10*(17). Scales over anal-fin pterygiophores approximately one-half the size of others.

Pectoral-fin rays, ii,13(3), ii,14(9), or ii,15*(12). Distal margin approximately straight. Tip of pectoral-fin reaching vertical through base of anal-fin rays 19–25. Analfin origin immediately posterior to vertical through pectoral-fin base; total anal-fin rays, 167–195 (189*, N = 15; Table 2). Distal margin of anal fin approximately concave. Caudal filament cylindrical, tapering gradually distally, relatively short and approximately 25% LEA in mature specimens.

Precaudal vertebrae, 12(1) or 13(2). Anterior vertebrae, 10(3); transitional vertebrae, 2(2) or 3(1). Displaced haemal spines, 2(1) or 3(1).

Coloration in alcohol: Background colour dark brown. Head dark brown dorsally and gradually becoming lighter ventrally. Lips and suborbital region yellowish. Body dark brown dorsally, gradually becoming lighter to region overlying anal-fin 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. Superior medial stripe thick, two scales deep, tapering from vertical between base of anal-fin rays 26–32 to posterior one-third of body. Inferior medial stripe moderately thick, two scales deep, extending from vertical between base of anal-fin rays 21–32 to posterior one-third of body. Anal-fin base stripe thick, two scales deep, extending from vertical between base of analfin rays 8–28 to last anal-fin ray. Pectoral and anal fins hyaline, with scattered tiny chromatophores on interradial membranes.

Distribution: Eigenmannia waiwai sp. nov. is known from Rio Mapuera, a tributary of the Rio Trombetas basin, Pará, Brazil ( Fig. 6 ).

Etymology: The epithet ‘ waiwai ’ is a reference to the indigenous people whose home territory proximates the type locality for the species.

Material examined

Holotype: Brazil. Pará: INPA 37594, 146.1 mm LEA, Rio Mapuera, Rio Trombetas basin, 01°05′ S, 57°02′ W, collected by E. Ferreira and M. Jégu, 19 April 1985.

Paratypes: Brazil. Pará: INPA 46985 , 24 + 2CS, 94.0– 138.1 mm LEA, collected with holotype . INPA 37597 , 3 + 1CS, 74.9–154.8 mm LEA, Rio Trombetas near Cachoeira Porteira, Município de Oriximiná , 01°04′45″ S, 57°02′39″ W, collected by E. Ferreira and M. Jégu, 19 April 1985 ; MZUSP 116798 , 3 , 95.8–122.29 mm LEA; MPEG 31166 , 3 , 104.2 – 123.43 , collected with holotype .

Comparative material examined

Archolaemus blax: INPA 6424, 4CS, 114.9–227.0 mm LEA, Rio Tocantins above Tucuruí Dam, Pará, Brazil. Archolaemus ferreirai: INPA 6422, 4CS paratypes, 125.8– 203.3 mm LEA, Rio Mucajaí, mouth of Igarapé Traíra, Roraima Brazil. INPA 36379, 1CS paratype, 111.3 mm LEA, Rio Mucajaí, Cachoeira Paredão 2, Roraima, Brazil. Archolaemus janeae: INPA 36380, 2CS paratypes, 114.9–131.0 mm TL, Rio Iriri, just upriver of its mouth into Rio Xingu, Pará, Brazil. Archolaemus luciae: INPA 20964, 2CS paratypes, 135.7–200.0 mm LEA, Rio Trombetas, Cachoeira Porteira, Pará, Brazil. Archolaemus orientalis: FMNH 94418, 1CS paratype, 129.0 mm LEA, Rio São Francisco at Pirapora, Minas Gerais, Brazil. Archolaemus santosi: INPA 36382, 3CS paratypes, 79.1–128.6 mm LEA, Rio Jamari, above site of Usina Hidroelétrica Samuel, Rondônia, Brazil. Eigenmannia goajira: USNM 121596, holotype, 377.0 mm LEA, Río Socuy, Zulia, Venezuela. USNM 121596, paratype, 335.6 mm LEA, Río Socuy, Río Socuy, Zulia, Venezuela. Eigenmannia humboldtii: NMW 64988, 1 syntype (only photo), Río Magdalena, Colombia. IAvH-P 6806, 1CS, 205.7 mm LEA, Yuto, Chocó, Colombia. IAvH-P 7415, 2, 241.0–270.0 mm LEA, Rio Atrato, Colombia. IAvH-P 7823, 1, 264.0 mm LEA, Rio Magdalena, Honda, Colombia. Eigenmannia limbata: INPA 28510, 2 + 1CS, 185.9–222.2 mm LEA, Rio Caeté, left tributary of Rio Purus, Acre, Brazil. MCP 28641, 1, 330.0 mm LEA, Lago Pirapora, Acre, Brazil. MNRJ 1186, holotype, 324.0 mm LEA, Amazonas, Brazil. Eigenmannia macrops: BMNH 1897.8.6.1, holotype, 128.5 mm LEA, Potaro River, British Guiana. USNM 402672, 12 + 2CS, 65.3–165.3 mm LEA, Cuyuni River, Cuyuni-Mazaruni, Guyana. Eigenmannia nigra: AMNH 58642, 3 paratypes, 235.4–296.5 mm LEA, Caño Urami, tributary of Rio Negro, Amazonas, Venezuela. Eigenmannia virescens: MACN 4536, 1, 98.0 mm LEA, Río de La Plata, Argentina. MACN 5122, 8, 162.0– 252.3 mm LEA, Río de La Plata, Argentina. MACN 5965, 15, 76.7–121.8 mm LEA, Río Paraná, Argentina. MACN 6040, 15, 105.9– 144.6 mm LEA, Río de La Plata, Argentina. MACN 6924, 6, 122.5– 184.9 mm LEA, Río Paraná, Argentina. MZUSP 22917, 1CS, 205.4 mm LEA, Río de La Plata, Argentina. Distocyclus conirostris: INPA 28879, 2CS of 19, 108.7–165.0 mm LEA, Carvoeiro, Rio Negro. MZUSP 6982, 2 + 1CS, 156.2–166.0 mm LEA, Rio Madeira. Japigny kirschbaum: FMNH 50185, 3CS, 94.2–108.3 mm LEA, New River drainage, head of Itabu Creek, Guyana. Rhabdolichops caviceps: INPA 20157, 8 + 2CS, 111.1–137.3 mm LEA, Paraná do Xiboquena, Rio Solimões, Amazonas, Brazil. Rhabdolichops eastwardi: MPEG 1189 , 2CS, 115.1–127.8 mm LEA, Rio Goiapi, Ilha do Marajó, Pará, Brazil. Rhabdolichops electrogrammus: INPA 28863, 8 + 2CS of 79,68.2– 164.1 mm LEA, Rio Negro, Amazonas, Brazil. Rhabdolichops lundbergi: INPA 11406, 7 + 3CS of 111, 124.2– 186.1 mm LEA, Rio Coari, tributary of Rio Solimões, Amazonas, Brazil. Rhabdolichops nigrimans: INPA 28862, 11 + 2CS, 109.7–143.8 mm LEA, Rio Negro, Amazonas, Brazil. Rhabdolichops troscheli: MPEG 2604 , 2CS, 93.0– 94.7 mm LEA, Rio Goiapi, Ilha do Marajó, Pará, Brazil. MPEG 2803, 1CS, 222.0 mm LEA, Rio Goiapi, Ilha do Marajó, Pará, Brazil. MPEG 8482, 1CS, 170.1 mm LEA, Tomé-Açu, Pará, Brazil. Sternopygus astrabes: INPA 30502, 2CS of 13, 112.0– 156.2 mm LEA, Igarapé Tucumã, Parque Estadual do Rio Negro, Amazonas, Brazil. Sternopygus macrurus: INPA 4869, 4CS of 6, 31.9–84.1 mm LEA, Paraná Janauacá, Lago Castanho, Amazonas, Brazil. Sternopygus xingu: MPEG 10191, 1CS, 136.0 mm LEA, FLONA Caxiuanã, Município de Portel, Pará, Brazil.

Figures

Figure 4. Schematic illustration of lateral view of maxilla: A, Eigenmannia matintapereira sp. nov. (MZUSP 109618, 118.3 mm LEA); B, Eigenmannia antonioi sp. nov. (MPEG 10182, 88.7 mm LEA). Cartilage represented by grey. Arrow indicates anterodorsal process. Scale bar: 1 mm.

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 23. Lateral view of Eigenmannia waiwai sp. nov., holotype, INPA 37594, 146.1 mm LEA, Rio Mapuera near Cachoeira Porteira, Rio Trombetas basin, Município de Oriximiná, Pará, Brazil, 1°04′60″ S, 57°01′60″ W.

Figure 24. Lateral view of head of Eigenmannia waiwai sp. nov., holotype, INPA 37594, 146.1 mm LEA, Rio Mapuera near Cachoeira Porteira, Rio Trombetas basin, Município de Oriximiná, Pará, Brazil, 1°04′60″ S, 57°01′60″ W.