Editorial Type:
Article Category: Research Article
 | 
Online Publication Date: 11 Dec 2024

Four New Species of Phenacogaster (Characiformes: Characidae) and a Review of Its Diversity in Colombia

and
Page Range: 619 – 644
DOI: 10.1643/i2023094
Save
Download PDF

The taxonomy of the genus Phenacogaster is reviewed in Colombia, and nine species are recognized in the country. This study includes the description of four new species using morphological data. The new species are: Phenacogaster yari, new species, from the Amazon River basin that differs from its congeners by the combination of an incomplete lateral line, the relative posterior position of the humeral spot, 29–32 branched anal-fin rays, six gill-rakers on the lower limb of the first gill arch, presence of bony hooks on pelvic-fin rays of males, absence of hooks on pectoral-fin rays of mature males, and a relatively shorter standard length (adult males with 25 mm SL); Phenacogaster nukak, new species, from the Orinoco River basin that differs from the other species by the combination of an incomplete lateral line, humeral spot far from the psedotympanum, 8–11 perforated scales in the lateral line, 29–30 teeth in the maxilla, 32–34 branched anal-fin rays, body height 28.8–43.3% SL, and pre-ventral length 37.4–41.7% SL; Phenacogaster tukano, new species, from the Amazon River basin that differs from the other species by the posteriorly displaced humeral spot and a complete lateral line; and Phenacogaster guayupe, new species, from the Orinoco basin is recognized by an incomplete lateral line, a large and round humeral spot near the pseudotympanum in females with width greater than half the ocular diameter, 2–3 large tricuspid teeth in the outer row of the premaxilla, and a pre-ventral length 36.4–43.3% SL. A taxonomic key for the identification of species is provided, together with distribution maps of all species in the genus in Colombia.

Copyright: © 2024 by the American Society of Ichthyologists and Herpetologists
Fig. 1.
Fig. 1.

Phenacogaster yari. (A) Holotype, MPUJ 17569, 25.0 mm SL, male, palm swamp tributary to the Yarí River, Caquetá River basin, Caquetá, Colombia. (B) Coloration in life, MPUJ 12212, photograph copyright A. Urbano-Bonilla.

Fig. 2.
Fig. 2.

Geographic distribution of Phenacogaster yari. Amazon and Yarí River basins are highlighted in gray.

Fig. 3.
Fig. 3.

Type localities. (A) Palm swamp tributary of Yarí River (Amazon Basin), collecting locality for Phenacogaster yari, photograph copyright A. Urbano-Bonilla. (B) Bonito Stream tributary of Inírida River (Orinoco Basin), collecting locality for P. nukak, photograph copyright A. Urbano-Bonilla. (C) Azul Stream tributary of Vaupés River (Amazon Basin), collecting locality for P. tukano, photograph copyright A. Urbano-Bonilla. (D) Abrote Stream tributary of Guaviare River (Orinoco Basin), collecting locality for P. guayupe, photograph copyright Josue Ocampo.

Fig. 4.
Fig. 4.

Phenacogaster nukak. (A) Holotype, MPUJ 17570, 34.95 mm SL, female, tributary of Grande River, Inírida River basin, Guaviare Department, Colombia. (B) Coloration in life of MPUJ 17768, 40.0 mm SL, paratype, Bonito Stream, tributary of Grande River, Inírida River basin, Guaviare Department, Colombia, photograph copyright A. Urbano-Bonilla.

Fig. 5.
Fig. 5.

Male bony hooks in branched rays of anal fin. (A) Phenacogaster nukak (MPUJ 12656, 30.7 mm SL) with small bony hooks from first to eleventh branched ray. (B) P. tukano (MPUJ 12648, 32.7 mm SL) with bony hooks from first or second to maximum thirteenth branched ray. (C) P. guayupe (MPUJ 10537, 32.9 mm SL) with bony hooks from first to twenty-first branched ray. From the eleventh branched ray, the hooks are noticeably larger. (D) P. napoatilis (MPUJ uncatalogued, 30.5 mm SL) with bony hooks from first to nineteenth branched ray, photograph copyright Omar Melo.

Fig. 6.
Fig. 6.

Geographic distribution of Phenacogaster nukak. Green symbol refers to the holotype locality, and red symbols to the paratype localities. Orinoco/Inírida River basins highlighted in gray.

Fig. 7.
Fig. 7.

Phenacogaster tukano. (A) Holotype, MPUJ 17571, 34.0 mm SL, female, tributary of Unilla River, Upper Vaupés River basin, Guaviare Department, Colombia. (B) Non-type, MPUJ 14364, 34.7 mm SL, male, tributary of the lower Vaúpes River basin, Vaupés Department, Colombia. (C) Life coloration, MPUJ 18195, 38.4 mm SL, paratype, Bálsamo Stream, tributary of Unilla River, upper Vaupés River basin, Guaviare Department, Colombia, photograph copyright A. Urbano-Bonilla.

Fig. 8.
Fig. 8.

Geographic distributions of Phenacogaster tukano. Green symbol refers to the holotype locality, red symbols to the paratypes localities, and black symbols to non-type localities. Amazon/Vaupés-Guainía River basins highlighted in gray.

Fig. 9.
Fig. 9.

Linear regression for morphometric parameters, comparing Phenacogaster tukano in lower and upper Vaupés River basins, with statistically significant differences according to ANOVA test P < 0.05. (A) Body height against standard length, (B) pre-dorsal length against standard length, (C) snout length against head length, and (D) orbital diameter against head length.

Fig. 10.
Fig. 10.

Phenacogaster guayupe. (A) Holotype, MPUJ 17572, 35.4 mm SL, female, Abrote Stream tributary to Ariari River, Guaviare River basin, Orinoco Basin, Colombia. (B) Paratype, male, MPUJ 10572, 38.4 mm SL, Hondo Stream, tributary of Guaviare River basin, Colombia. (C) Coloration in life, MPUJ 10572, 38.4 mm SL, Hondo Stream, tributary of Guaviare River basin, Colombia, photograph copyright A. Urbano-Bonilla.

Fig. 11.
Fig. 11.

Geographic distribution of Phenacogaster guayupe. Green symbol refers to the type locality, and red symbols to the paratype localities. Orinoco and Guaviare River basins are highlighted in gray.

Fig. 12.
Fig. 12.

Diversity of species of the genus Phenacogaster in Colombia. Detail of the humeral spot in relation to pseudotympanum. pt: pseudotympanum; hs: humeral spot; pr: pleural ribs after the pseudotympanum. (A) Phenacogaster yari, MPUJ 12212, 25.0 mm SL. (B) Phenacogaster nukak MPUJ 12656, 34.9 mm SL. (C) Phenacogaster tukano, MPUJ 12638, 34.0 mm SL. (D) Phenacogaster guayupe, MPUJ 10534, 35.4 mm SL. (E) Phenacogaster maculoblonga (Meta basin), MPUJ 11771, 42.4 mm SL. (F) Phenacogaster maculoblonga (Guaviare basin), MPUJ 9644, 39.0 mm SL. (G) Phenacogaster napoatilis, MPUJ uncatalogued, 37.8 mm SL, photograph copyright Omar Melo. (H) Phenacogaster pectinata, MPUJ 3456, 29.5 mm SL. (I) Phenacogaster prolata, IAvH 6164, 35.1 mm SL, photograph copyright Susana Bernal. (J) Phenacogaster retropinnus, MPUJ 14373, 38.5 mm SL.

Fig. 13.
Fig. 13.

Geographic distributions of all species of the genus Phenacogaster in Colombia. Cross: P. yari. Star: P. nukak. Asterisk: P. tukano. Triangle: P. guayupe. Pentagon: P. retropinnus. Circle: P. maculoblonga. Semicircle: P. napoatilis. Square: P. pectinata. Diamond: P. prolata.

Fig. 14.
Fig. 14.

Linear regression comparing populations of P. maculoblonga for morphometric parameters with statistically significant differences according to ANOVA test P < 0.05. (A) Body height against standard length, (B) occipital–dorsal length against standard length, and (C) head length against standard length.

Fig. 15.
Fig. 15.

Linear regression comparing P. napoatilis and P. guayupe for morphometric parameters with statistically significant differences according to ANOVA test P < 0.05. (A) Caudal-peduncle height against standard length, (B) pectoral-fin length against standard length, (C) pelvic-fin length against standard length, (D) head length against standard length, and (E) maxillary length against head length.

Fig. 16.
Fig. 16.

Linear regression comparing P. yari and P. nukak for morphometric parameters with statistically significant differences according to ANOVA test P < 0.05. (A) Caudal-peduncle length against standard length, (B) pelvic–anal length against standard length, and (C) orbital diameter against head length.

Contributor Notes

1  Universidad El Bosque, Facultad de Ciencias, Programa de Biología, Carrera 9na No. 131 A-2, Bogotá, Colombia; ORCID: 0000-0002-5156-2383; Email: bromerof@unbosque.edu.co. Send correspondence to this address.
2  Laboratorio de Ictiología, Unidad de Ecología y Sistemática (UNESIS), Departamento de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana, Carrera 7 No. 43-82, Bogotá D.C., Colombia; ORCID: 0000-0001-5901-1634; Email: pitiago@javeriana.edu.co

Associate Editor: R. E. Reis.

Received: 15 Nov 2023
Accepted: 29 Aug 2024
  • Download PDF