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| Rhyacoglanis rapp-pydanielae Shibatta, Rocha & de Oliveira, 2021 |
Abstract
A new species of Rhyacoglanis is described from the rapids of Jatobal, Pará State, Brazil. This species differs from the congeners by fusing hypurals 3, 4, and 5 (vs. hypural 5 free). It also differs from the other species, except for Rhyacoglanis epiblepsis, by the color pattern with numerous dark spots on the body, short post-cleithral process, rounded pectoral and caudal fins, and incomplete lateral line. This species is known only from the type locality, which is currently flooded by the Tucuruí reservoir.
Keywords: Biodiversity; Bumblebee catfish; Ostariophysi; Systematics; Taxonomy
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Rhyacoglanis rapp-pydanielae, holotype, INPA 8060, 37.5 mm SL, rio Tocantins, state of Pará, Brazil. |
Rhyacoglanis rapp-pydanielae, new species
Diagnosis. Rhyacoglanis rapp-pydanielae is diagnosed from congeners by presenting the hypural bones 3, 4, and 5 fused (vs. hypural 5 free; Fig. 5). The new species also differs from its congeners, except for Rhyacoglanis epiblepsis, by the short post-cleithral process, with only a tiny visible tip after the opercular membrane (vs. elongated, more than half length visible after opercular membrane; Fig. 2), body scattered with numerous dark brown spots of diameter approximately equal to that of the eye (vs. few dark brown spots or absent), rounded pectoral and caudal fins (vs. pointed fins), and incomplete long lateral line (vs. complete). Rhyacoglanis rapp-pydanielae is distinguished from R. epiblepsis by the more tapered shape of the caudal peduncle’s dark brown band and the thin caudal fin’s dark brown band.
Geographical distribution. Rhyacoglanis rapp-pydanielae is known only from the type locality, Jatobal rapids, lower rio Tocantins basin, Pará, Brazil (Fig. 6). Unfortunately, collectors did not determine the exact geographic localization. However, the coordinates 04º28’26.5”S 49º27’18.24”W were recovered with Google Maps to Jatobal, Goianésia do Pará municipality, state of Pará.
Etymology. The specific name rapp-pydanielae is a homage to the Brazilian ichthyologist Lucia H. Rapp Py-Daniel for her outstanding contribution to Neotropical fishes’ systematics. She is the founder and current curator of the fish collection at Instituto Nacional de Pesquisas da Amazônia (INPA), whose scientific importance is recognized by the national and international communities.
Oscar A. Shibatta, Marcelo S. Rocha and Renildo R. de Oliveira. 2021. New species of Rhyacoglanis (Siluriformes: Pseudopimelodidae) from rio Tocantins basin, northern Brazil. Neotrop. ichthyol. 19(4); DOI: 10.1590/1982-0224-2021-0083
Resumo: Uma nova espécie de Rhyacoglanis é descrita das corredeiras de Jatobal, estado do Pará, Brasil. Essa espécie difere das congêneres pela fusão dos hipurais 3, 4 e 5 (vs. hipural 5 livre). Também difere das demais espécies, exceto de Rhyacoglanis epiblepsis, pelo padrão de colorido com inúmeras pintas escuras no corpo, processo pós-cleitral curto, nadadeiras peitoral e caudal arredondadas, e linha lateral incompleta. Essa espécie é conhecida apenas da localidade tipo, que atualmente se encontra inundada pelo reservatório de Tucuruí.
Palavras-chave: Bagrinho; Biodiversidade; Ostariophysi; Sistemática; Taxonomia