Loricaria nimairaco, new species from the upper Amazon in Colombia

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Loricaria nimairaco

Londoño-Burbano, A., Urbano-Bonilla, A., Thomas, M.R., & M.R. Britto. (2023). A new species of Loricaria (Loricariidae: Loricariinae) from the upper Amazon River basin, Colombia. Neotrop. Ichthyol., 21(3):e230008. https://doi.org/10.1590/1982-0224-2023-0008

Abstract
A new species of Loricaria is described from the upper Amazon River basin, Colombia. The new species is distinguished from its congeners primarily by having the dorsal portion of head with uniform black or dark brown coloration extending to three or four plates posterior to dorsal fin base, or with two longitudinal bands from tip of the snout to origin of dorsal fin; abdominal plates tightly joined and completely covering the median abdominal space and pectoral girdle; and pectoral and dorsal fins totally black or dark brown, without bands, spots, or blotches. The new species is further distinguished by plate counts, and body measurements. An analysis of genetic distances using the cytochrome oxidase c subunit 1 marker of the mitochondrial genome showed a clear differentiation between the new species and Loricaria cataphracta (5.8–7.6%), L. nickeriensis (5.7–6.1%), and L. simillima (2.7–7.0%). Species delimitation analyses were carried out, which further supported the new species as a divergent lineage within the genus. Fish species diversity of the upper Amazon River basin and taxonomic issues related to L. simillima are included as part of the discussion.

Keywords: COI; Orteguaza River; Putumayo River; Species delimitation analyses

FIGURE 1. Holotype of Loricaria nimairaco, ICN-MHN 24398, 185.8 mm SL, Colombia, Amazonas, Leticia, Amazonas River. Scale bar = 10 mm. Photos: Gabriel Cortés.

FIGURE 2. Loricaria nimairaco, paratype, MPUJ 17399, 180.4 mm SL, Colombia, Putumayo, Puerto Asís, Putumayo River. Scale bar = 10 mm. Photos: Omar E. Melo-Ortiz.

FIGURE 6. Lateral view of head showing size of post-orbital notch in: A. Loricaria nimairaco, holotype, ICN-MHN 24398, 185.8 mm SL; and B. Loricaria nickeriensis, holotype, ZMA-PISC 107561, 116.4 mm SL.

FIGURE 7. Dorsal view of Loricaria nimairaco male, showing a slightly hypertrophied pectoral spine indicating sexual dimorphism, paratype, ICN-MHN 9156, 190.9 mm SL, Colombia, Amazonas, Leticia, Amazonas River system, Laguna Yahuarcaca. Photo: Alexander Urbano-Bonilla.