Monday, September 7, 2026

[Ichthyology • 2026] Petulanos jasteri • A New Species of Petulanos (Characiformes: Anostomidae) from the Rio Araguari, Amapá State, Brazil

 

Petulanos jasteri
Birindelli, Lima & Gama, 2026


Abstract
The Neotropical family Anostomidae comprises over 150 valid species, though its true diversity remains underestimated. The genus Petulanos currently includes four species distributed across northern South America, all characterized by upturned mouths, compressed multicuspid dentition, and distinctive color patterns. In this study, we describe Petulanos jasteri, a new species apparently endemic to the rio Araguari, Amapá state, Brazil. Despite hosting extensive protected areas, Amapá remains poorly surveyed, and its ichthyofauna is still insufficiently documented. The new species is readily distinguished from congeners by its color pattern, consisting of three vertically elongated dark blotches on the posterior half of the trunk (without pale margins) combined with eight to ten dark vertical bars. It lacks the horizontal stripes that characterize P. brevior, as well as the rounded blotch above the pectoral fin present in P. intermedius, P. plicatus, and P. spiloclistron, and has 38 or 39 lateral-line scales (vs. 40 to 42 in P. spiloclistron). Osteological characters confirm its assignment to Petulanos, sharing synapomorphies such as four branchiostegal rays, bicuspid symphyseal premaxillary tooth, symplectic with a distinctive triangular ventral lamina, and open cranial fontanel. Petulanos jasteri, new species, is the first species of the genus reported from the rio Araguari. Its discovery emphasizes the underestimated diversity of the Anostomidae and highlights the need for further surveys and integrative studies in poorly explored basins of northern Brazil.

Petulanos jasteri.
(A) Holotype, IEPA 6078, 72.9 mm SL, Amapá, Ferreira Gomes, rio Mutum, tributary to rio Araguari, at Parque Nacional Montanhas do Tumucumaque.
(B) Paratype, ZUEC 14774, 83.7 mm SL, Amapá, Ferreira Gomes, rio Araguari.
(C) Paratype, ANSP 211099 (ex. IEPA 6079), 64.1 mm SL, rio Mutum, tributary to rio Araguari, at Parque Nacional Montanhas do Tumucumaque, photographed alive.
Scale bar = 10 mm. 

Petulanos jasteri, a new species 

Etymology.—The specific name jasteri honors Dr. Christoph Bernhard Jaster, formerly chief of the Tumucumaque National Park and the Amapá National Forest, for having made possible many field expeditions in these Conservation Units for the IEPA Ichthyology team, being a great supporter of basic science and biological surveys at Amapá State.


José L. O. Birindelli, Flávio C. T. Lima, Cecile S. Gama. 2026. New Species of Petulanos (Characiformes, Anostomidae) from the Rio Araguari, Amapá State, Brazil. Ichthyology & Herpetology. 114(3):451-460. DOI: doi.org/10.1643/i2025080 [28 August 2026]