[Ichthyology • 2025] Characidium dumonti • A New Species of Characidium (Characiformes: Crenuchidae) from the Iguaçu National Park, Rio Iguaçu Basin, Paraná, Brazil

 

 Characidium dumonti 

Stabile, Reis, Oliveira & Graça, 2025

DOI: doi.org/10.1111/jfb.70035

Abstract

A new species of Characidium is described from the Iguaçu National Park, Brazil. The new species can be diagnosed from the congeners by the absence of conspicuous vertical bars, blotches and spots along the sides of the body, the presence of a scaled isthmus and adipose fin, a series of scales below lateral line and the presence of a thin dark midlateral stripe. The reticulated colour pattern of melanophores along the posterior edge of scales found in the new species is similar to that found in C. xanthopterum, with which it presents 4.2% of genetic distance. Morphological and molecular analyses showed that it is a new species, supported by multiple species delimitation methods (Assemble Species by Automatic Partitioning, the General Mixed Yule Coalescent method, and the Poisson Tree Process and its Bayesian implementation). The new species is a sister group of C. itarare, a species that occurs in the Paranapanema river basin (upper Paraná river). Despite being located within a conservation unit, the new species is known from only two creeks, raising concerns about its long-term conservation.

Keywords: COI, conservation unit, freshwater fish, integrative taxonomy, south American darters

Live specimens of Characidium dumonti before fixation, sampled in Córrego Carlos Giovanni, tributary of Rio São João, Rio Iguaçu basin, Lower Rio Paraná.

 Photograph by Natália de Paula Lopes.

  Characidium dumonti, sp. nov.

Diagnosis: Characidium dumonti can be distinguished from its congeners, except Characidium bolivianum Pearson 1924, C. chicoi da Graça, Ota & Domingues 2019, C. iaquira Zanata, Ohara, Oyakawa & Dagosta 2020, C. kamakan Zanata & Camelier 2015, C. lanei Travassos 1967, C. nana Mendonça & Netto-Ferreira 2015, C. samurai Zanata & Camelier 2014, C. summus Zanata & Ohara 2015, C. tapuia Zanata, Ramos & Oliveira-Silva 2018, and C. xanthopterum Silveira, Langeani, da Graça, Pavanelli & Buckup 2008 by the absence of conspicuous dark-brown vertical bars, blotches and spots along the sides of body (vs. presence of conspicuous dark-brown vertical bars, blotches and spots along the sides of body in the remaining congeners). Characidium dumonti can be distinguished from C. bolivianum, C. iaquira, C. kamakan, C. lanei and C. summus by the scaled isthmus (vs. scaleless isthmus). From C. chicoi and C. nana by the presence of adipose fin (vs. absence of adipose fin). From C. xanthopterum by the presence of five scales series below lateral line (vs. four). From C. samurai and C. tapuia by the presence of a thin dark midlateral stripe occupying half scale height in vertical through dorsal-fin origin and one scale height on caudal peduncle (vs. broad lateral stripe occupying at least one scale height). The new species can be further distinguished from all congeners except C. xanthopterum by the presence of a reticulated colour pattern, with melanophores along the posterior edge of the scales (vs. absence of a reticulated colour pattern, without melanophores along the posterior edge of the scales) and from C. xanthopterum by the shorter dorsal and pelvic-fin height, 19.1%–23.7% and 12.1%–18.1% of Ls (vs. 24.9%–32.2% and 21.6%–27.4% of Ls), and shorter predorsal distance 44.5%–48.0% of Ls (vs. 49.2%–56.7% of Ls).

Etymology: The specific name dumonti was chosen in honour of Alberto Santos-Dumont (1873–1932), who is regarded as the father of aviation. In 1916, Dumont visited the area around the Iguaçu Falls and worked to convince the government to create a natural park there. His efforts were essential for the establishment of the Iguaçu National Park, a place that protects the type locality of Characidium dumonti and home of many other species. A genitive.

  

Map of the distribution of Characidium dumonti, inside Iguaçu National Park (INP-orange), Rio Iguaçu, lower Rio Paraná basin, Paraná, Brazil. The yellow circles represent localities of paratypes and the red star represents the type locality.

 

Bruno H. M. Stabile, Renan B. dos Reis, Alessandra V. de Oliveira and Weferson J. da Graça. 2025. A New Species of Characidium (Characiformes: Crenuchidae) from the Iguaçu National Park, Rio Iguaçu Basin, Paraná, Brazil. Journal of Fish Biology. DOI: doi.org/10.1111/jfb.70035 [09 April 2025]

[Ichthyology • 2023] Characidium fleurdelis • A New sexually dichromatic Miniature Characidium (Characiformes: Crenuchidae) from the rio Guaporé, rio Madeira Basin, Brazil, with Remarkable Morphological Novelties to the Genus

Characidium fleurdelis

 Zanata, Oliveira-Silva & Ohara, 2023

DOI: 10.1590/1982-0224-2022-0059   

Abstract

A new miniature species of Characidium is described from the midde rio Guaporé, rio Madeira basin, Rondônia, Brazil. The new species can be readily distinguished from all congeners by the sexual dichromatism, with females having narrow dark bars on body absent in males, and by the presence, in both sexes, of a black midventral dashed line extending from area between contralateral pectoral fins to at least the anal-fin origin. It can also be diagnosed from congeners by having strongly tricuspid teeth, with well developed and similar sized cusps in the premaxilla and outer series of dentary, and short lateral line with 6–8 perforated scales. Morphological novelties to Characidium observed in the new species include a rounded process on the first pleural rib near the vertebra, three or four haemal spines of the first caudal vertebrae distinctly elongate, neural and haemal spines of the antepenultimate vertebra not reaching origins of dorsal and ventral procurrent rays nor the origin of the caudal-fin rays.

Keywords: Amazon fishes; First rib; Haemal spine; Sexual dimorphism; Tricuspid teeth

Characidium fleurdelis:
 A. Holotype, MZUSP126956, female, 21.6 mm standard length, lateral view;
 B. Paratype, UFBA 9234, female, 22.9 mm SL, lateral, dorsal and ventral views;
C. Paratype, UFBA 9234, female, 23.8 mm SL, lateral view; D. Paratype, UFBA 9234, male, 20.6 mm SL, lateral view; E. Paratype, UFBA 9233, juvenile, 17.4 mm SL, lateral view.
All from rio Guaporé sub basin, rio Madeira basin, Rondônia, Brazil.

Characidium fleurdelis, paratypes, INPA 59848, lateral view:
A. Freshly preserved specimens, top male, 22.2 mm SL; bottom mature female with ovocytes seen by transparency on belly as a yellowish area, 24.1 mm SL;
B. Live specimens, top male, 20.6 mm SL; bottom mature female, 24.0 mm SL. All from rio Guaporé sub basin, rio Madeira basin, Rondônia, Brazil.

Characidium fleurdelis, new species

 

 Diagnosis. Characidium fleurdelis differs from congeners, except C. longum, C. pellucidum, and C. pteroides by having teeth in the premaxilla and outer series of dentary strongly tricuspid, with three well developed and similar sized cusps (Fig. 2) (vs. teeth uni- or if tricuspid with median cusp distinctly larger; e.g., Agudelo-Zamora et al., 2020, Fig. 4; Melo et al., 2021; Figs. 3A,B). The new species differs from the aforementioned congeners by the presence of a dark (occasionally interrupted) narrow midlateral stripe on the body (vs. absence of dark midlateral stripe), the presence of a black midventral dashed line extending from area between contralateral pectoral fins to at least the anal-fin origin (Fig. 1B) (vs. absence of interrupted black line throughout ventral midline of body in C. longum and C. pteroides, and midventral black line restricted to the area posterior to pelvic fins in C. pellucidum), and the presence of sexual dichromatism, with females having narrow dark bars on laterals of body and males without it (Figs. 1, 5) (vs. sexual dichromatism absent). Characidium fleurdelis also differs from the three aforementioned species and remaining congeners, except C. bahiense Almeida, 1971, C. cacah Zanata, Ribeiro, Araújo-Porto, Pessali & Oliveira-Silva, 2020, C. chicoi Graça, Ota & Domingues, 2019, C. interruptum Pellegrin, 1909, C. laterale (Boulenger, 1895), C. mirim Netto-Ferreira, Birindelli Buckup, 2013, C. nana Mendonça & Netto-Ferreira, 2015, C. nupelia Graça, Pavanelli & Buckup, 2008, C. rachovii Regan, 1913, C. stigmosum Melo & Buckup, 2002, and C. xavante Graça, Pavanelli Buckup, 2008, by having a short lateral line with 6–8 perforated scales (vs. lateral line with more than 14 perforated scales). The new species can be distinguished from C. cacah, C. chicoi, C. mirim, C. nana, C. nupelia, C. stigmosum, and C. xavante by the presence of adipose fin (vs. absence), from C. bahiense and C. laterale by having two dentary teeth rows (vs. one), from C. rachovii by the absence of roundish black marks on the pelvic, dorsal, and anal fins (vs. presence) and from C. interruptum by having 12 circumpeduncular scales (vs. 14). Other features useful to diagnose the new species from most congeners includes: first pleural rib with a rounded process posteriorly directed near the vertebra (Fig. 3A) (vs. absence of such a process or, if present, triangular or L shaped); neural and haemal spines of the antepenultimate vertebra not reaching origins of dorsal and ventral procurrent rays, respectively, nor the origin of the caudal-fin rays (Fig. 3B) (vs. neural and haemal spines of the antepenultimate vertebra reaching origins of procurrent rays or the origin of the caudal-fin rays); and three to four haemal spines of caudal vertebrae anterior to the anal fin flattened and distinctly elongate (Figs. 3C, D) (vs. haemal spines anterior to the first anal-fin proximal radial with tapered tip, comparatively shorter than the neural spine of the same vertebra and similar in length or rarely longer than the haemal spines situated above the anal fin). See “Discussion” for additional comments.

Dentary of Characidium fleurdelis, UFBA 9234, paratype, male, 21.0 mm SL, outer view.

Etymology. Named in allusion to the similarity of the three pointed flower-like teeth of the species with a stylized flower called fleur-de-lis. Géry, (1960) was the first author, apparently, to point out the resemblance of such form of teeth with a fleur-de-lis in his description of Microcharacidium eleotrioides (Géry, 1960). Lily or iris, the flower upon which the emblem fleur-de-lis is historically related, was the flower of Hera, the Greek moon goddess, being the symbol of purity. Also, the fleur-de-lis is often related with the sacred lotus symbol for “plant” meaning “Tree of Life”. A noun in apposition.

A. Map with part of the rio Madeira basin, Brazil, showing the type locality (black star) of Characidium fleurdelis; symbol may represent more than one locality or lot.
B. Sampling locality of Characidium fleurdelis, Rondônia, Corumbiara town, Vitória da União district, stream tributary of rio Oimerê, tributary of rio Corumbiara, rio Guaporé sub basin, rio Madeira basin.

 

Angela Maria Zanata, Leonardo Oliveira-Silva and Willian M. Ohara. 2023. A New sexually dichromatic Miniature Characidium (Characiformes: Crenuchidae) from the rio Guaporé, rio Madeira Basin, Brazil, with Remarkable Morphological Novelties to the Genus.  Neotrop. ichthyol. 21(1); DOI: 10.1590/1982-0224-2022-0059    

Resumo: Uma nova espécie miniatura de Characidium é descrita do médio rio Guaporé, bacia do rio Madeira, Rondônia, Brasil. A nova espécie pode ser facilmente distinguida de todas as congêneres pelo dicromatismo sexual, com barras escuras estreitas no corpo das fêmeas ausentes nos machos, e por ter uma linha preta mediana ventral tracejada em ambos os sexos, que se estende da área entre as bases das nadadeiras peitorais até pelo menos a origem da nadadeira anal. A espécie também pode ser diagnosticada das congêneres por ter dentes fortemente tricúspides, com cúspides bem desenvolvidas e de tamanho semelhante no pré-maxilar e série externa do dentário, e linha lateral curta com 6–8 escamas perfuradas. Novidades morfológicas para Characidium observadas na nova espécie incluem presença de um processo arredondado na primeira costela pleural próximo à vértebra, três ou quatro espinhos hemais das primeiras vértebras caudais distintamente alongados, espinhos neurais e hemais da antepenúltima vértebra não atingindo as origens dos raios procorrentes dorsal e ventral, nem a origem dos raios da nadadeira caudal.

Palavras-chave: Dentes tricuspidados; Dimorfismo sexual; Espinho hemal; Peixes amazônicos; Primeira costela

[Ichthyology • 2022] Poecilocharax callipterus & P. rhizophilus • The Monophyly of Crenuchinae and Description of Two New Species of Poecilocharax (Characiformes: Crenuchidae) based on Phenotypic and Genotypic Evidence

Poecilocharax callipterus   

Ohara, Pastana & Camelier, 2022

 

DOI: 10.1093/zoolinnean/zlac026 

 twitter.com/NMNH 

Abstract

Crenuchinae is a subfamily of the fish family Crenuchidae distributed in the Amazon Basin with pronounced sexual dimorphism and exuberant colour patterns. Recent fieldwork in the tributaries of the Rio Aripuanã drainage, a large tributary of the Rio Madeira (Amazon Basin), resulted in the discovery of two distinctive, undescribed species of the crenuchin genus Poecilocharax, which are formally described herein, combining morphological and molecular data. These are the first representatives of Crenuchinae discovered after a gap of 57 years and the first records of Poecilocharax from the tributaries of the right bank of the Rio Amazonas draining the Brazilian crystalline shield. Based on a taxonomic review including all species of the subfamily, we provide an expanded morphological diagnosis for Crenuchinae. This now includes characteristics related to the lateral-line canals of head and body, the number of dorsal-fin rays and sexually dimorphic traits. In addition, we review previous characteristics used to diagnose Crenuchus and Poecilocharax, providing comments on their polarity and distribution across the subfamily. A dichotomous key is provided for the first time for species of Crenuchinae.

Amazon, COI gene, DNA, freshwater fishes, lateral line, phylogeny, taxonomy, tetras

Poecilocharax callipterus

Poecilocharax rhizophilus

 

Willian M. Ohara, Murilo Pastana and Priscila Camelier. 2022. The Monophyly of Crenuchinae and Description of Two New Species of Poecilocharax (Teleostei: Crenuchidae) based on Phenotypic and Genotypic Evidence. Zoological Journal of the Linnean Society. zlac026. DOI: 10.1093/zoolinnean/zlac026

 twitter.com/NMNH/status/1526225093541642240

[Ichthyology • 2020] Characidium iaquira • A New Rheophilic South American Darter (Characiformes: Crenuchidae: Characidium) from the rio Juruena Basin, Brazil, with Comments on Morphological Adaptations to Life in Fast‐flowing Waters

Characidium iaquira

Zanata, Ohara, Oyakawa & Dagosta, 2020

 DOI: 10.1111/jfb.14485

 Researchgate.net/publication/343505882 

 Abstract

Characidium iaquira, a new species from the upper rio Juruena, rio Tapajós basin, Brazil, is described. The new species can be promptly distinguished from all congeners by having a unique v‐shaped dark mark lying along the caudal‐fin extension, in medium‐ and large‐sized specimens, and a remarkable iridescent green colouration in life. Characidium iaquira is closely related to Characidium crandellii and Characidium declivirostre by sharing unambiguous synapomorphies such as branchiostegal membranes united to each other across the isthmus, a scaleless area extending from the isthmus to the pectoral girdle, and dermal flaps surrounding anterior and posterior naris independent, but touching each other distally. Morphological specializations of the paired fins in the three riffle‐dwellers species are discussed, including the wing‐like shape, robustness, and inclination of the pectoral fin.

Keywords: Amazon, Characidium crandellii, Characidium declivirostre, Characiformes, pectoral fin

 

Live specimens of Characidium iaquira from rio Juruena sub basin, upper rio Tapajós basin, Mato Grosso, Brazil:
 (a) holotype, MZUSP 125780, 64.6 mm standard length, lateral and dorsal views;
 (b) paratype, MZUSP 125644, 48.4 mm standard length, lateral view. 

Aquarium specimens of Characidium iaquira

 

(a) Characidium iaquira, holotype, MZUSP 125780, 64.6 mm standard length, rio Juruena sub basin, upper rio Tapajós basin, Mato Grosso, Brazil, ventral view of the anterior portion of the body.
(b) Characidium cf. declivirostre, MZUSP 122324, 68.8 mm standard length, rio Juma basin, Amazonas, Brazil, ventral view of the anterior portion of the body.
(c) Characidium iaquira, holotype, dorsal view of the pectoral fin, white arrow indicates swollen membrane covering basal portion of fin and black arrow indicates posteriormost rays abutting body wall.

  Characidium iaquira sp. n.

Etymology: The specific name iaquira comes from the Tupi language, meaning green (Miranda, 1942), in allusion to the remarkable iridescent green colouration of body of the species in life. A noun in apposition.

Angela M. Zanata, Willian M. Ohara, Osvaldo T. Oyakawa and Fernando C. P. Dagosta. 2020. A New Rheophilic South American Darter (Crenuchidae: Characidium) from the rio Juruena Basin, Brazil, with Comments on Morphological Adaptations to Life in Fast‐flowing Waters. Journal of Fish Biology. DOI: 10.1111/jfb.14485 

Researchgate.net/publication/343505882_A_new_Characidium_from_the_rio_Juruena_basin_Brazil

[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

ni.bio.br/1982-0224-2020-0152

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 

[Ichthyology • 2021] Redescription of the Guiana Shield Darter Species Characidium crandellii and C. declivirostre (Characiformes: Crenuchidae) with Descriptions of Two New Species: Characidium duplicatum & C. wangyapoik

Characidium crandellii Steindachner, 1915; C. declivirostre Steindachner, 1915; 

Characidium duplicatum & C. wangyapoik 

 Armbruster, Lujan & Bloom, 2021

 DOI: 10.1643/i2019299 

  twitter.com/IchsAndHerps 

  twitter.com/DrNathanLujan 

Abstract  

Based on collections made in the western Guiana Shield over the last 21 years, Characidium crandellii and C. declivirostre are redescribed and two similar species are described from Guyana. These species all have enlarged paired fins with three to four rays thickened ventrally on the pectoral fin and two rays thickened on the pelvic fin. The species can be separated from all other Characidium and Melanocharacidium by having the venter unscaled from the isthmus to the pelvic origin. Characidium crandellii is found in the Essequibo and Takutu River systems and in an isolated population above Tencua Falls in the Ventuari River and the upper Paragua River (Orinoco River basin). Characidium declivirostre is found throughout the right-bank, shield tributaries of the Orinoco River system and in the upper Negro River. Characidium duplicatum, new species, appears to be rare but widely distributed in the Essequibo River system. Characidium wangyapoik, new species, is only known from the upper Ireng River, Branco River basin, along the border between Brazil and Guyana.

Characidium crandellii Steindachner, 1915

Characidium declivirostre Steindachner, 1915

Characidium duplicatum, new species

Distribution.—(Fig. 9) Found throughout the Essequibo River basin, but has been rarely encountered during our surveys. Most locations are in the lower Potaro and Kuribrong, but two localities are in the upper Essequibo upstream of the mouth of the Kuyuwini River.

Etymology.—Duplicatum is Latin for double and is a neuter adjective. In reference to the presence of two unbranched anal-fin rays.

 

Characidium wangyapoik, new species

Distribution.—(Fig. 9) Characidium wangyapoik is only known from the upper Ireng River basin (Amazon River) along the Brazil/Guyana border (known as the Rio Mau in Brazil). Specimens were collected from below Orinduik Falls to the upper falls on the Ireng and its equal tributary, the Sukwabi River, but not above the Uluk Tuwuk or Wotawanda falls of the upper Ireng and Sukwabi Rivers (see Lujan et al., 2020, for a more detailed map and description of this area).

Etymology.—Wangyapoik is the Patamona word for the species, and it is used as a noun in apposition. Wang means ‘honey' and yapoik means ‘seated,’ perhaps in reference to the yellowish color. The Patamona also refer to the species by the English common name of “fallsfish.”

Jonathan W. Armbruster, Nathan K. Lujan and Devin D. Bloom. 2021. Redescription of the Guiana Shield Darter Species Characidium crandellii and C. declivirostre (Crenuchidae) with Descriptions of Two New Species. Ichthyology & Herpetology. 109(1); 102-122. DOI: 10.1643/i2019299 

  twitter.com/IchsAndHerps/status/1376589176653680647

  twitter.com/DrNathanLujan/status/1376935828862173187

[Ichthyology • 2016] Characidium clistenesi • A New Species of Characidium Reinhardt, 1867 (Characiformes: Crenuchidae) from the Chapada Diamantina, Bahia, Brazil

Characidium clistenesi 

 Melo & Espíndola, 2016  

DOI:  10.11646/zootaxa.4196.4.5 

Abstract  

A new species of Characidium Reinhardt, 1867 endemic to tributaries of the upper rio Paraguaçu in the Chapada Diamantina, Bahia, Brazil, is described. The new species can be distinguished from its congeners except C. bahiense, C. bimaculatum, C. laterale, C. nana, C. nupelia, and C. xavante, by having a conspicuous peduncular blotch in addition to the basicaudal spot on the base of the middle caudal-fin rays. Among other features, the new species differs from C. bahiense, C. laterale, C. nana, C. nupelia, and C. xavante by having a complete lateral line with 32–36 perforated scales (vs. lateral line short, with 9–11 perforated scales), and from C. bimaculatum by the body pigmentation pattern, with secondary bars present (vs. absent), total bars 11–16 (vs. 10–12), peduncular blotch rounded (vs. horizontally elongated), and mature males not having a darker dorsal fin (vs. proximal third of dorsal fin darker in mature males). Characidium bimaculatum, a poorly known species from Northeastern Brazil, is redescribed.

Keywords: Pisces, Northeastern Brazil, rio São Francisco, Bacia do Nordeste Oriental, Caatinga, semiarid biome

Field underwater photographs of Characidium clistenesi sp. nov. taken in rio São José (voucher MZUSP 120487)

DOI:  10.11646/zootaxa.4196.4.5

Characidium clistenesi, new species 

Piaba-charuto, charutinho 

Characidium bimaculatum (non Fowler, 1941): Leitão & Buckup, 2014: 21 (material examined, in part. MNRJ 23757, 23764, both from rio São José, Lençóis, Bahia). 

Characidium cf. bimaculatum (non Fowler, 1941): Santos, 2003: 27, 75, 77, 78 (checklist and estimative of abundance of species from rio Paraguaçu, Chapada Diamantina).

Etymology. The specific name is dedicated to our colleague Dr. Alexandre Clistenes de Alcântara Santos, in recognition of his long time of dedication in researching the natural history of the ichthyofauna of the Chapada Diamantina, Bahia, Brazil.

Marcelo R.S. Melo and Vinicius C. Espíndola. 2016. Description of A New Species of Characidium Reinhardt, 1867 (Characiformes: Crenuchidae) from the Chapada Diamantina, Bahia, and Redescription of Characidium bimaculatum Fowler, 1941.

  Zootaxa.   4196(4); 552–568. DOI:  10.11646/zootaxa.4196.4.5