Endemicity Analysis of the Ichtyofauna of the Rio Doce Basin, Southeastern Brazil.

The Rio Doce is a very important freshwater system in Brazil running through the Atlantic Forest, however available information about its biodiversity is scarce. In 2015, the Rio Doce basin was damaged by a burst of Fundão tailing dam in Mariana (Minas Gerais) causing an extraordinary environmental damage, with consequences still incompletely known. In the present paper we analyzed 6042 latitude/longitude records of 208 fish species from the Rio Doce deposited in collections prior to November 2015, in order to identify areas of endemism in the river before the burst. Several areas of endemism were identified along the basin, most of them describing small and novel patterns. Our analyses helped to identify areas of major diversity along the basin as well as information gaps concerning fish sampling. We hope this contribution will help obtaining quantitative measures on the impact caused by the Fundão dam catastrophe on fish biodiversity and will be useful to orient general actions towards the restoration of the basin.

A new species of driftwood catfish emCentromochlus/em Kner, 1858 (Siluriformes, Auchenipteridae, Centromochlinae) from Tocantins-Araguaia River drainage.

The genus Centromochlus includes eight catfish species in the Amazon and Orinoco river systems: C. schultzi from Xingu and Tocantins-Araguaia rivers; C. melanoleucus from Tapajós and Teles Pires rivers; C. macracanthus from Negro River; C. orca from Nhamundá River; C. heckelii and C. existimatus from Amazon and additionally at the Essequibo rivers; C. carolae and C. musaica from Orinoco River system. Recent field expeditions and collection examination revealed an undescribed species of Centromochlinae that has compatible features with Centromochlus. We herein describe a new species of Centromochlus from the Tocantins-Araguaia River drainage, diagnosed among most Centromochlinae by having a vermiculated color pattern on the dorsum and included in Centromochlus by sharing the derived features: ventrolateral position of eye socket; sphenotic notched for the exit of infraorbital canal; and posterior serrations along pectoral-fin spine numerous. The new species is diagnosed from congeners by having the pectoral-fin spine with dark bars, alternating with light bars (vs. pectoral-fin spine with light and uniform color in all Centromochlus); and it is further distinguished from its congeners (except C. carolae) by the ventral surface of head moderate to largely pigmented (vs. ventral surface of head unpigmented in C. heckelii, C. existimatus, C. orca, C. musaicus, C. schultzi, with few scattered dark chromatophores in C. macracanthus and C. melanoleucus; see diagnosis). A discussion about the systematics of the genus, plus the conservation status of the new species, and an identification key to species of Centromochlus, are also provided.

Description of a new species of Tatia from rio Tocantins drainage, central Brazil, with notes on Tatia simplex Mees, 1974 (Siluriformes, Auchenipteridae)

Tatia comprises twenty-five valid species, distributed in the main inland watersheds of South America, including the Orinoco, Essequibo, and coastal rivers of Suriname, Amazon, upper rio Paraná and São Francisco basins. A new species is described from tributaries of upper rio Manuel Alves on uplands of Serra Geral do Tocantins plateau, Tocantins State, Brazil. It is promptly distinguished from all congeners, except Tatia britskii, due to absence of an adipose fin. It differs from T. britskii by the longer caudal peduncle length (24.1-30.5% SL, mean 25.3 vs. 20.0-22.7, mean 20.9); caudal peduncle depth (10.9-16.8 SL, mean 14.1 vs. 9.4-10.5, mean 9.8), and anterior cranial border with mesethmoid width equals its length (vs. width approximately three times its length in T. britskii). Additionally, information regarding the poorly known species Tatia simplex originally described from rio das Mortes, is provided.(AU)

Tatia abriga vinte e cinco espécies válidas distribuídas nos maiores sistemas fluviais de águas interiores da América do Sul, como o Orinoco, Essequibo, e rios costeiros do Suriname, Amazonas, alto Paraná e São Francisco. Uma espécie nova é descrita para tributários do alto rio Manuel Alves, nos contrafortes da Serra Geral do Tocantins, estado do Tocantins, Brasil. A espécie nova é facilmente distinguida de todos os congêneres, exceto Tatia britskii, pela ausência de nadadeira adiposa. Difere de T. britskii pelo maior comprimento do pedúnculo caudal (24,1-30,5% CP, média 25,3 vs. 20,0-22,7% CP, média 20,9); altura do pedúnculo caudal (10,9-16,8 SL, mean 14,1 vs. 9,4-10,5, mean 9,8) e margem craniana anterior com largura do mesetmoide igual a seu comprimento (vs. largura aproximadamente três vezes no seu comprimento em T. britskii). Adicionalmente, são fornecidas informações sobre Tatia simplex, uma espécie pouco conhecida, descrita para o rio das Mortes.(AU)

Distribution, morphological notes and conservation status of the psammophilus Microcambeva catfishes (Siluriformes: Trichomycteridae).

Sarcoglanidinae and Glanapteryginae catfishes are among the most unusual elements of the Neotropical freshwater fish fauna. Microcambeva ribeirae, M. barbata and M. draco are miniaturized Sarcoglanidinae known to occur in sandy microhabitats in drainages of the Brazilian Atlantic Forest. Due to their specific habitats, specimens of Microcambeva are rare in fish collections, and new records are considered noteworthy to warrant report. Recently, specimens of this genus were newly found in the Rio Doce basin in Minas Gerais and Espírito Santo States. Such new records expand the known geographic distribution of Microcambeva. Further records of Microcambeva for Rio Peruípe in south Bahia State are also reported. Comments on the distribution of Microcambeva species along the Atlantic Forest coastal basins and suggestions on its conservation status are also offered.

A new species of Characidium Reinhardt (Ostariophysi: Characiformes: Crenuchidae) from coastal rivers in the extreme south of Bahia, Brazil.

Characidium helmeri, a species of the family Crenuchidae apparently endemic to rivers draining the extreme south of Bahia, Brazil, is described. The new species is easily distinguished from congeners by having dark, vertically elongated, irregular spots or dashes on flanks, usually more evident over midlateral stripe and/or ventral half of body, where it may present a somewhat curved or zigzag-shape. Characidium helmeri can be further distinguished from most congeners by having lateral line reduced to 13-22 pored scales, adipose fin absent, isthmus naked on its anteriormost portion, 14 scales around caudal peduncle, 4 scales above lateral line and 4 below, two series of dentary teeth, supraorbital absent or extremely reduced, and basicaudal black spot well defined. The occurrence of reductive characters in Characidium is briefly discussed.

Redescription of moenkhausia doceana (Steindachner, 1877) (ostariophysi: characiformes): a characid from the northeastern mata atlântica ecoregion, Brazil

Moenkhausia doceana is redescribed from the northeastern mata atlântica ecoregion drainages in Espírito Santo, Minas Gerais, and Bahia states. The species is distinguished from its congeners by a long anal fin, with 29-34 (mode 32) branched rays; 4-7 (mode 5) maxillary teeth; and 7-8 (mode 7) scale rows above lateral line at dorsal-fin origin. Phylogenetic hypothesis about its relationships among the Characidae is also presented and commented.

Moenkhausia doceana é redescrita das drenagens da ecorregião mata atlântica Nordeste nos estados do Espírito Santo, Minas Gerais e Bahia. A espécie distingue-se das demais congêneres por apresentar uma nadadeira anal longa, com 29-34 (moda 32) raios ramificados; 4-7 (moda 5) dentes maxilares e 7-8 séries horizontais de escamas acima da linha lateral até a origem da nadadeira dorsal. Hipótese filogenética sobre suas relações em Characidae é também apresentada e comentada.

Trichomycterus payaya, new catfish (Siluriformes: Trichomycteridae) from headwaters of rio Itapicuru, Bahia, Brazil

Trichomycterus payaya, new species, is described from tributaries to the upper rio Itapicuru basin, northern Bahia State, Brazil. The new species is distinguished from congeners by having the head rounded anteriorly in dorsal view and slightly depressed in lateral view, supraorbital pores s6 paired, opening laterally on the supraorbital sensory branch, not emerging from an epiphyseal branch, lateral process of the urohyal distally sharp and with pointed tip, interopercular patch of odontodes longer than deep, with 21-26 odontodes, small number of pleural ribs (5-6 ribs), and dorsal fin in a posterior position. This is the first record of a Trichomycterus from the semiarid region of northeastern Brazil.

Trichomycterus payaya, espécie nova, é descrita de tributários do alto rio Itapicuru, norte do Estado da Bahia, Brasil. A espécie nova distingue-se dos congêneres por ter cabeça arredondada anteriormente em vista dorsal e ligeiramente deprimida em vista lateral, poros supraorbitais s6 pares, abrindo-se lateralmente no ramo sensorial supraorbital, não emergindo a partir de um ramo epifiseal, processo lateral do urohial afilado distalmente e com extremidades pontiagudas, placa de odontódeos interoperculares mais longa que larga, com 21-26 odontódeos, baixo número de costelas pleurais (5-6 costelas) e nadadeira dorsal em posição posterior. Este éo primeiro registro de um Trichomycterus para o semi-árido do nordeste do Brasil.

Ituglanis cahyensis, a new catfish from Bahia, Brazil (Siluriformes: Trichomycteridae)

A new trichomycterid catfish of the genus Ituglanis is described from the rio Palmares, a tributary of the rio Cahy in southeast Bahia State, Brazil. Ituglanis cahyensis is distinguished from all other congeners through a combination of characters, as the supraorbital laterosensory canal branch with pores s3 and s6 present, the low count of branched pectoral fin rays, and low number of paired ribs. It is further distinguished in proportional measurements, such as elongate nasal, maxillary, and rictal barbels, and small eye diameter.

É descrito um novo trichomycterídeo do gênero Ituglanis, capturado no rio Palmares, um tributário do rio Cahy, na costa sudeste do estado da Bahia, Brasil. Ituglanis cahyensis distingue-se das demais espécies congêneres por uma combinação de caracteres, como o canal laterosensorial supraorbital com os poros s3 e s6 presentes, um pequeno número de raios ramificados nas nadadeiras peitorais, e um pequeno número de costelas. Distingue-se ainda quanto a proporções morfométricas, como os barbilhões nasal, maxilar e rictal alongados, e o pequeno diâmetro ocular.