Wednesday, July 14, 2021

[Ichthyology • 2021] Characidium kalunga • A New Species of Characidium (Characiformes: Crenuchidae) from the Chapada dos Veadeiros, Goiás, Brazil


  Characidium kalunga 
Melo, Bouquerel, Masumoto, França & Netto-Ferreira, 2021


Abstract​ 
A new species of Characidium is described from the tributaries of the rio Tocantinzinho, rio Tocantins basin, located in the southern portion of the Chapada dos Veadeiros, at about 1,200 meters of elevation, Goiás, Brazil. The new species can be diagnosed by an unusual combination of two apomorphic features present in distinct clades of Characidium, the presence of a scaleless isthmus in allied to with a single row of dentary teeth. Additionally, the new species has a unique color pattern of inconspicuous vertical bars disconnected from the dorsal midline, forming seven to nine square blotches along body sides, and the presence of a dark saddle-shaped mark at the dorsal-fin base. Osteologically, it can be diagnosed by having the first and second anal-fin proximal radials fused and contacting the third hemal spine, which is branched. The new species also has a peculiar, unusual variation of fin-ray counts among its congeners.

Keywords: Cerrado, Characidium stigmosum, Endemism, Rio Tocantins basin, Taxonomy.

FIGURE 1: Characidium kalunga in lateral (top), ventral (middle) and dorsal (bottom) views, holotype, MZUSP 125824, 40.5 mm SL, rio Almécegas at Cachoeira de Almécegas, Chapada dos Veadeiros, Alto Paraíso de Goiás, Brazil.

Characidium kalunga, new species

Diagnosis. Characidium kalunga can be distinguished from its cis-Andean congeners, except C. alipioi Travassos, 1955, C. amaila Lujan, Agudelo-Zamora, Taphorn, Booth & López-Fernández,2013, C. boavistae Steindachner, 1915, C. bolivianum Pearson, 1924, C. crandellii Steindachner, 1915, C. duplicatum Ambruster, Lujan & Bloom, 2021, C. cricarense Malanski Sarmento-Soares, Silva-Malanski, Lopes, Ingenito & Buckup, 2019, C. declivirostre Steindachner, 1915, C. fasciatum Reinhardt, 1867, C. gomesi Travassos, 1956, C. grajahuense Travassos, 1944, C. hasemani Steindachner, 1915, C. helmeri Zanata, Sarmento-Soares & Martins-Pinheiro, 2015, C. iaquira Zanata, Ohara, Oyakawa & Dagosta, 2020, C. japuhybensis Travassos, 1949, C. kamakan Zanata & Camelier, 2015, C. lauroi Travassos, 1949, C. macrolepidotum (Peters, 1868), C. oiticicai Travassos, 1967, C. pterostictum Gomes, 1947, C. purpuratum Steindachner, 1882, C. schubarti Travassos, 1955, C. tamata Agudelo-Zamora, Tavera, Murillo & Ortega-Lara, 2020, C. timbuiense Travassos, 1946, C. travassosi Melo, Buckup & Oyakawa, 2016, C. vidali Travassos, 1967, and C. wangyapoik Ambruster, Lujan & Bloom, 2021, by lacking scales on the isthmus (vs. isthmus completely scaled), from C. alipioi, C. amaila, C. boavistae, C. bolivianum, C. crandellii, C. cricarense, C. declivirostre, C. fasciatum, C. gomesi, C. grajahuense, C. hasemani, C. helmeri, C. iaquira, C. japuhybensis, C. kamakan, C. lauroi, C. macrolepidotum, C. oiticicai, C. pterostictum, C. purpuratum, C. schubarti, C. tamata, C. timbuiense, C. travassosi, C. vidali by having a single row of dentary teeth (vs. dentary teeth in two rows, internal row with minute conical teeth), and from C. duplicatum and C. wangyapoik by having the scalelles are extending from isthums to anterior margin of cleithra (vs. scalelles extending on isthmus, area between pectoral fins and part of belly to level of pelvic fins). It can be further distinguished from its congeners, except C. heirmostigmata da Graça & Pavanelli, 2008, C. papachibe Peixoto & Wosiacki, 2013, C. satoi Melo & Oyakawa, 2015, and C. serrano Buckup & Reis, 1997, by having vertical bars on body that are disconnected dorsally, and from those species by having the bars on body as deep as wide, forming blotches two to four scales wide (vs. blotches vertically elongated, and of one scale width in C. heirmostigmata, C. papachibe, and C. serrano, or blotches forming oval dots, V-shaped, W-shaped, or diamond-shaped marks along and ventral to the lateral line in C. satoi), and bars not obliquely oriented (vs. bars oblique in C. heirmostigmata, C. papachibe, and C. serrano), and from all congeners by the presence of a saddle mark at the base of the second to eighth dorsal-fin rays. Osteologically, C. kalunga is diagnosed by having the first and second anal-fin proximal radials fused and contacting the third hemal spine (vs. separated and intercalated with the hemal spines), and by the third hemal spine branched (vs. all hemal spines unbranched).

FIGURE 6: Underwater photography of Characidium kalunga in the rio Preto, at the Parque Nacional da Chapada dos Veadeiros, Goiás, Brazil (not collected).

Ecological notes. Characidium kalunga is a bottom dweller species, known from localities with elevation of about 1,200 meters. It inhabits rivers with fast flowing, cold, black water with rocky bottom, characterized by the presence of many rapids, canyons, and relatively large waterfalls, alternating with pools with sandy bottom. Those rivers are often impacted by sudden water flow increase caused by precipitation runoff in the watershed. The Cerrado vegetation is restricted to the margins, with no aquatic plants present in the river channel (Fig. 8).

Etymology. The specific name honors the Comunidade Quilombola Kalunga, a resilient community of Afro-Brazilians that lives in the Chapada dos Veadeiros area, helping to protect its natural resources. Kalunga also means a sacred place in the African Bantu language. A noun in apposition.
 

Marcelo R. S. Melo, Bárbara B. Bouquerel, Flávia T. Masumoto, Rayane S. França and André L. Netto-Ferreira. 2021. A New Species of Characidium (Characiformes: Crenuchidae) from the Chapada dos Veadeiros, Goiás, Brazil.  Neotropical Ichthyology. 19(2) ni.bio.br/1982-0224-2020-0152