Guilherme Moreira Dutra

Trichomycterus anhanga, a new species of miniature catfish related to T. hasemani and T. johnsoni (Siluriformes: Trichomycteridae) from the Amazon basin, Brazil

Trichomycterus anhanga is described from the Amazon basin, northern Brazil. The species is diagnosed by the latero-sensory system which is restricted to LL1 and LL2, the pectoral fin with two branched rays, the absence of pelvic fins and girdle, the reduced jaws and pharyngeal dentition, the presence of six to seven interopercular odontodes, the absence of a lateral series of spots, the presence of a small dark spot on the ventral surface of the mandibular symphysis, the narrow comma-shaped palatine, the absence of procurrent rays anterior to the dorsal and anal fins, the position of insertion of the first dorsal-fin pterygiophore and the presence of a single pair of pleural ribs. Trichomycterus anhanga shares with T. hasemani and T. johnsoni a wide cranial fontanel which occupies most of the skull roof. Miniaturization as well as synapomorphies for the T. hasemani group are discussed.

The South American Electric Glass Knifefish Genus Distocyclus (Gymnotiformes: Sternopygidae): Redefinition and Revision

Electric glass knifefishes of the genus Distocyclus, family Sternopygidae, are reviewed. Features previously utilized to diagnose Distocyclus were found uninformative as to whether the two species originally assigned to the genus are sister taxa. Distocyclus goajira was found to lack the derived features present in the type-species of the genus, D. conirostris and instead shares derived features with Archolaemus, Eigenmannia, and/or Japigny; however, the relationships of Distocyclus goajira among those genera cannot be resolved. In light of this evidence, Distocyclus is restricted to its type species, D. conirostris, which is defined on a series of derived characters, and D. goajira is assigned as incertae sedis in the Eigenmanniinae under a new combination of “Eigenmannia” goajira. Distocyclus conirostris is redescribed on the basis of multiple samples from across the Amazon, Essequibo, and Orinoco river basins. Os peixes elétricos do gênero Distocyclus, família Sternopygidae, são revisados. Os caracteres diagnósticos previamente propostos para Distocyclus se mostraram não informativos em relação as duas espécies originalmente alocadas neste gênero como espécies irmãs. Distocyclus goajira não apresenta os caracteres derivados presentes na espécie tipo do gênero, D. conirostris, e ainda compartilha caracteres derivados em diferentes combinações com Archolaemus, Eigenmannia e Japigny. Baseado na presente evidência, Distocyclus é restringido a sua espécie tipo, D. conirostris que é definido por uma série de caracteres derivados e D. goajira é considerada incertae sedis em Eigenmanniinae, sob a nova combinação de “Eigenmannia” goajira. Distocyclus conirostris é redescrito com base em várias amostras ao longo das bacias dos rios Amazonas, Essequibo e Orinoco.

Two new species of Cyphocharax (Teleostei: Characiformes: Curimatidae) from headwaters of the Jequitinhonha and São Francisco river basins, Minas Gerais, Brazil

Two new species of Cyphocharax from southeastern Brazil are described. Both new species share with C. punctatus, and C. vanderi the presence of a midlateral series of irregular patches of dark pigmentation along the lateral line. Cyphocharax jagunco, new species, from Rio Jequitinhonha basin, is distinguished from C. lundi, C. punctatus, and C. vanderi by the number of patches of dark pigmentation along lateral line; the number of pored scales posterior to the hypural joint; the number of scales in the lateral line; and the number of scales rows above lateral line. Cyphocharax lundi, new species, from Rio São Francisco basin, is distinguished from C. jagunco, C. punctatus, and C. vanderi by the presence of dark spots above the lateral line; and the number of scales in the lateral line. Comments on the relationships of the new species within Cyphocharax are presented.

A New Species of the Electric Fish Genus Hypopygus (Gymnotiformes: Hypopomidae) from the Lower Amazon Basin, Brazil

Hypopygus benoneae, new species, is described from streams in the lower Rio Anapu, in the eastern portion of the Amazon basin, Brazil. The new species is diagnosed from all congeners by a unique set of characters, including the absence of the sixth infraorbital bone and 115–134 total anal-fin rays. Hypopygus benoneae, new species, is a member of a clade also comprising H. hoedemani, H. lepturus, and H. minissimus. The description of H. benoneae, new species, brings the number of species in Hypopygus to nine. A dichotomous key to the species of Hypopygus is provided. Hypopygus benoneae, nova espécie, é descrita para igarapés do baixo Rio Anapu, na porção oriental da bacia Amazônica, Brasil. A nova espécie é diagnosticada de todos os congêneres por uma combinação única de caracteres, tais como a ausência do sexto osso infraorbital e o número total de raios da nadadeira anal 115–134. Hypopygus benoneae, nova espécie, é um membro do clado que também inclui H. hoedemani, H. lepturus, and H. minissimus. A descrição de H. benoneae, nova espécie, eleva o número de espécies em Hypopygus para nove. Uma chave dicotômica para as espécies de Hypopygus é fornecida.

A New Species of the Glass Electric Knifefish Genus Eigenmannia Jordan and Evermann (Teleostei: Gymnotiformes: Sternopygidae) from Río Tuíra Basin, Panama

A new species of Eigenmannia is described from the Río Pucuro, Río Tuíra basin, Panama. It is diagnosed from all congeners by the position of the mouth, the color pattern, the number of anal-fin rays, the number of scales on lateral line, the number of scales rows above the lateral line, the number and arrangement of teeth on the dentary, the number of precaudal vertebrae, the relative depth of the posterodorsal expansion on infraorbitals 1+2, and the relative size of coronomeckelian bone. The new species is the first Eigenmannia described from Central American drainages, and the northernmost species of the genus. Una nueva especie de Eigenmannia es descrita del río Pucuro, que pertenece a la cuenca del Río Tuíra, Panamá. Esta diagnosticada de las demás especies del género por la posición de la boca, el padrón de coloración, el número de radios de la aleta anal, el número de escamas de la línea lateral, el número de hileras de escamas arriba de la línea lateral, el número y disposición de los dientes en el hueso dentario, el número de vertebras pre-caudales, el tamaño relativo de la expansión postero-dorsal del hueso infraorbital 1+2 y el tamaño relativo del hueso corono-meckeliano. Esta nueva especie es la primera Eigenmannia descrita de las cuencas de América Central y además es la especie con la distribución más boreal del género.

A new species of Eigenmannia Jordan & Evermann (Teleostei: Gymnotiformes: Sternopygidae) from Río Ventuari, Venezuela

A new species of Eigenmannia is described from the Río Ventuari, Río Orinoco basin, Venezuela. It is distinguished from congeners by the presence of a bony dorsolateral flange on the dentary, the presence of teeth attached along a bony dorsolateral flange, and by the first premaxillary teeth attached to the anteroventral margin of the premaxilla. It is further distinguished from all remain congeners by a combination of characters, including a subterminal mouth, 99-107 scales along the lateral line until the end of the anal fin, and ii, 16-17 pectoral-fin rays.

A new annual fish of the genus Simpsonichthys (Cyprinodontiformes: Cynolebiidae) from the upper Rio Jequitinhonha basin, Brazil

A new species of Simpsonichthys is described from the upper rio Jequitinhonha basin, Minas Gerais, eastern Brazil. It is diagnosed from all congeners by presenting an A-patterned frontal squamation. Additionally, males of the new species differs from all congeners by the color pattern of body, the color of iris, the absence of contact organs in the pectoral fin, presence of scales on anal-fin base, pectoral-fin length, caudal fin length, and eye diameter. Females of the new species can be diagnosed from remaining congeners by the pectoral-fin length. The conservation status of the new species is evaluated. Comments on the relationships of the new species within the genus Simpsonichthys are presented.

A new species of Pimelodella (Siluriformes: Heptapteridae) from the Guiana Shield, Brazil

A new species of Pimelodella is described from the Rio Ipitinga, Rio Jari basin, a left bank tributary of the Rio Amazonas in Brazil. The new species is diagnosed from all congeners by having a dark oval mark on the humeral region. It also differs from all congeners by a unique set of characters, including the presence of 47 to 49 total vertebrae, unpigmented areas dorsally and ventrally adjacent to the dark midlateral stripe, and maxillary barbels reaching at least to vertical through caudal fin insertion. Faunal similarities between the southern part of the eastern Guiana Shield and coastal drainages in the Guianas and Suriname are discussed.