Eigenmannia magoi, Lopes E Silva & Andrade & Maltoni & Lannes, 2020

Herrera-Collazos, Edgar Esteban, Galindo-Cuervo, Aleidy M., Maldonado-Ocampo, Javier A. & Rincón-Sandoval, Melissa, 2020, Three new species of the Eigenmannia trilineata species group (Gymnotiformes: Sternopygidae) from northwestern South America, Neotropical Ichthyology (Cambridge, England) 18 (1), No. 180085, pp. 1-28 : 16-17

Eigenmannia magoi , new species

urn:lsid:zoobank.org:act:29463771-B47A-4C39-AD8D-352C85CE0E6B

( Figs. 7–8 ; Tab. 9 )

Holotype. ICN-MHN 2318, 1, 13.1 mm LEA, (COI: GenBank MN200122 ), Colombia, Norte de Santander, La Gabarra, Catatumbo river, Catatumbo basin, 8°59’55.28”N 72°54’08.64”W, J. I. Mojica & M. Camargo.

Paratypes. IAvH-P 15913, 19–20.5, 1c&s, 171.4 mm LE, Colombia, Norte de Santander, Zulia river, Agualasal gully, Catatumbo Basin , 8°13’24.89”N 72°32’00.70”W, Carlos DoNascimiento, J. G. Albornoz-Garzón & M. H. Sabaj. IAvH-P 11768, 25, 81.0– 141.0 mm LEA, Colombia, Norte de Santander, La Gabarra , Catatumbo river , Catatumbo basin, 8°59’55.28”N 72°54’08.64”W, A. Ortega-Lara. ICN-MHN 2383, 1 c&s, (COI: GenBank MN200109 ) 17.5 mm LE, Colombia, Norte de Santander, La Gabarra, Tigre creek , Catatumbo basin, 9°01’00.98”N 72°51’57.52”W, G. Gálvis & M. Camargo .

Non-types. CZUT EV _ T 63, 12, 8.6–16.7 mm LEA, Colombia, Norte de Santander, Agualasal gully, Catatumbo basin, 8°13’05.00”N 72°32’31.20”W.

Diagnosis. Eigenmannia magoi can be distinguished from its congeners of the E. trilineata species group, except E. trilineata and E. zenuensis by the number of premaxillary teeth: 32 in 4 rows (vs. 8–10 in 2 rows in E. muirapinima ; 8–12 in 2 rows in E. antonioi ; 9–10 in 2 rows in E. guairaca ; 11–15 in 3 rows in E. loretana ; 13–16 in 3 rows in E. pavulagem ; 16 in 3 rows in E. microstomus ; 17 in 3 rows in E. sayona ; 17–20 in 3 rows in E. correntes ; 18–29 in 3–4 rows in E. besouro ; 22–24 in 4 rows in E. matintapereira ; 24–25 in 4 rows in E. desantanai ; 25–26 in 4 rows in E. vicentespelaea ; 27 in 3–4 rows in E. camposi and 35–40 in 5 rows in E. waiwai ); it can further be distinguished from E. trilineata and E. zenuensis by the number of teeth in the dentary: 35–39 in 2–3 rows (vs. 23 in 2 rows in E. trilineata and 56–60 in 4–5 rows in E. zenuensis ); finally it can further be distinguished from E. zenuensis by the shape of the vomer with extensions separated at the posterior end (vs. vomer extensions forming an inverted ridge in E. zenuensis ) and by the lower number of teeth in the upper pharyngeal plate 5–6 (vs. 7 in E. zenuensis ).

Description. Morphometric and meristic data is presented in Tab. 10 . Total Length (mm): 158.0–298.9. Ovoid scapular foramen. 74 vertebrae; 14 precaudal vertebrae. 32 premaxillary teeth in 4 rows. 11 endopterygoid teeth in 2 rows. 35–39 teeth in dentary in 2–3 rows. Suture between parietal and frontal bones serrated with variable teeth size. Three or more foramina on the opercular opening of the frontal bone. Posterior-most arm of the lateral ethmoid bone elongated, articulates with anterior-most prolongation of frontal bone forming window. Orbitosphenoid bone wide. Pterosphenoid bone wide. Posterior edge of pterotic bone not rounded, instead oval and extended. Branchiostegal rays 5 in total, 1–2 of similar length, 3–5 with wide extensions, branchiosteal 4 the largest. Operculum upper edge rounded. Endopterygoid with long ascendant process. Basihyal length approximately 1/2 of length of first ceratobranchial, slightly wider in anterior region, almost rectangular. In all ceratobranchials width is conserved. 4 basibranchials, 1–2 well ossified, 3 lightly ossified. Four hypobranchials, first 3 well ossified. Tooth plate of the upper pharyngeal with 5–6 teeth. Tooth of the lower pharyngeal plate with 12 teeth. 10 cartilaginous gill rakers.

Coloration in alcohol. Background color pales white to pale yellow. Head dark, darker on the dorsal region getting lighter gradually to the ventral region. Upper lip usually darker than the lower lip, but generally slightly dark; suborbital region dark with concentrated chromatophores. Body with four visible dark horizontal stripes. Above the lateral-line stripe, dispersed chromatophores present along myomeres, making them more observable. Lateral-line stripe thin narrow, one scale deep, the first half portion of the stripe light in color in the anterior half of body, darker on posterior half; stripe starts on the first perforated scale and extends posteriorly to base of the caudal filament. Superior medial stripe very light-colored, made up of dispersed chromatophores, more visible on posterior two-thirds of the body. Inferior medial stripe dark and thick wide, two scales thick wide, originating above anus and extending along length of the anal fin. Stripe along anal-fin base thin narrow, one scale thick wide, dark, extending along the base of the complete entire anal fin. Pectoral fin slightly dark-colored, mainly hyaline, darker near its base. Anal fin hyaline. Humeral spot present, dark brownish. Nape dark.

Geographic distribution. Eigenmannia magoi is known only from the Catatumbo river basin, which drains into Lake Maracaibo in Colombia and Venezuela ( Fig. 7 ).

Etymology. The specific epithet “ magoi ” is assigned to the new species in honor of Francisco Mago Leccia (1931–2004), for his contributions to our knowledge of gymnotiform fishes.

Figures

FIGURE 7 | Map illustrating the known geographic distribution of Eigenmannia camposi (circles), E. zenuensis (squares), and E. magoi (triangles). Red symbols indicate type localities.

FIGURE 8 | Holotype ICN-MHN 2318 for Eigenmannia magoi, scale bar 1 cm.