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Rhyacoglanis annulatus Shibatta & Vari, 2017

Image contributors to this species:

Mark Sabaj Pérez (1)

ScotCat Sources:

Other Sources:

Relevant Information:

Description: Rhyacoglanis annulatus is known solely from the southern portions of the Río Orinoco basin in Venezuela. Rhyacoglanis, a new genus of the South American freshwater catfish family Pseudopimelodidae is described from cis-Andean portions of the continent. Rhyacoglanis is distinguished from other genera of the family by three synapomorphies: presence of a light blotch on the cheek; a connection between the middle of the dark caudal-fin stripe and the dark caudal-peduncle pigmentation; and 30-35 total vertebrae. Species of Rhyacoglanis are rheophilic and strongly associated with rapids and other swift-flowing waters. A phylogenetic analysis based on 41 morphological characters yields a hypothesis of monophyly of the Pseudopimelodidae and Rhyacoglanis. Pimelodus pulcher Boulenger, 1887, from the western Amazon basin is designated as type-species of the new genus and redescribed. Four new species are described: Rhyacoglanis annulatus, from the río Orinoco basin, with a nearly ringed dark band on the caudal peduncle, and a larger distance between anus and anal-fin origin; R. epiblepsis, from the rio Madeira basin, with numerous dark spots scattered on the body, and rounded caudal-fin lobes; R. paranensis from the upper rio Paraná basin, with three distinct dark bands on the body, and 31-33 total vertebrae; and R. seminiger, from the rio Juruena basin, with subdorsal and subadipose dark bands fused anteroposteriorly, and a separate dark band on the caudal peduncle. Aquarium Care: Predatory in the aquarium towards fish that are smaller. Provide plenty of hiding places to hide during the day and best kept in a small group of 2-3. Very secretive in its surroundings. Diet: No problem with eating all types of aquarium fare, flake, tablets, pellets, live and frozen foods. Etymology: The specific name annulatus: Latin adjective meaning ringed, in reference to the caudal-peduncle band with a light inner region.

Common Name:

None

Synonyms:

None

Family:

Pseudopimelodidae

Distribution:

South America: Río Orinoco basin, Venezuela. Type locality: Río Orinoco basin, Río Ventuari, exposed cobble beach along base of Cerro Moriche, about 1 km upstream of Moriche community, 167 km E-NE of San Fernando de Atabapo, 04o45’12.46”N 66o22’21”W

Size:

6.0cm. (2½ins)

Temp:

24-28°C (75-83°F)

p.H.

6.0-7.5.

IUCN Red List

This known distribution of this species is restricted and there is no information on the population status or threats. Therefore, although the species is registered in a protected area and a large part of the upper Orinoco basin is highly conserved, it is assessed as Data Deficient. A review and update of records and specimens in biological collections is recommended, (IUCN 2021).

Reference:

Crispim-Rodrigues JL, Silva GSC, Shibatta OA, Kuranaka M, Oliveira C. Description and phylogenetic position of a new species of Rhyacoglanis (Siluriformes: Pseudopimelodidae) from the Jamanxim River basin. Neotrop Ichthyol. 2023; 21(3):e230051.
Shibatta, O.A. and R.P. Vari, 2017. A new genus of Neotropical rheophilic catfishes, with four new species (Teleostei: Siluriformes: Pseudopimelodidae). Neotropical Ichthyology 15(2):e160132.
Villa-Navarro, F., DoNascimiento, CD, Mojica, J.I., Taphorn, D.C., Usma, S. & Herrera-Collazos, E.E. 2021. Rhyacoglanis annulatus. The IUCN Red List of Threatened Species 2021.

Family: Pseudopimelodidae Back to Ident-A-Cat Click on Thumbnails

Rhyacoglanis annulatus

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