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| Sternopygus sabaji Torgersen & Albert, 2022 DOI: 10.1643/i2022013 |
Abstract
Sternopygus sabaji, new species, is described from the Atlantic drainages of the Guiana Shield region of South America using traditional methods of morphometrics and meristics and microcomputed tomography (µCT) scans for osteological analysis. The new species is diagnosed from all other species of Sternopygus by the lack of dentition on the anteroventral surface of the endopterygoid and by the possession of a wider mouth. It further differs from its congeners by the following combination of characters: reduced humeral spot with low-contrast and poorly defined margins, possession of a light-colored mid-lateral stripe along posterior portion of lateral line, possession of 1–3 dark saddle-like markings along dorsum of smaller individuals, and a relatively low precaudal vertebrae count. This work provides the first description of a species of Sternopygus that is endemic to the Guiana Shield, joining S. astrabes and S. macrurus in elevating the species richness of the clade in that region to three species and the total number of valid Sternopygus to ten species.
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| Sternopygus sabaji, holotype, ANSP 208090 (374 mm TL). (A) Full body view; (B) closeup of head. Position of anus and urogenital papilla indicated by arrow. Scale bar = 1 cm. |
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| Paratype specimen of Sternopygus sabaji ANSP 189018 (146 mm TL). (A) Specimen with live coloration, photo taken after collection in 2007. (B) Same specimen with preserved coloration photographed in 2021. Scale bar = 1 cm. Photo of specimen with live coloration by Mark Sabaj. |
Sternopygus sabaji, new species
Etymology.—This species is named in honor of Dr. Mark
Henry Sabaj, of the Academy of Natural Sciences, Philadelphia, for his many contributions to the exploration and
understanding of Neotropical aquatic diversity. The authors
also acknowledge his role in collecting and photographing
the specimens of the type series and his help to the authors
in obtaining specimen loans for this study.
Distribution.— Sternopygus sabaji is known from the Marowijne (Maroni) and Essequibo drainage basins where it is
found sympatrically with S. macrurus and possibly another
undescribed member of the genus (Fig. 10).
Kevin T. Torgersen and James S. Albert. 2022. A New Species of Sternopygus (Gymnotiformes: Sternopygidae) from the Atlantic Coast of the Guiana Shield. Ichthyology & Herpetology. 110(4), 714-727. DOI: 10.1643/i2022013
