Landscape dynamics and diversification of the megadiverse South American freshwater fish fauna.

Landscape dynamics are widely thought to govern the tempo and mode of continental radiations, yet the effects of river network rearrangements on dispersal and lineage diversification remain poorly understood. We integrated an unprecedented occurrence dataset of 4,967 species with a newly compiled, time-calibrated phylogeny of South American freshwater fishes-the most species-rich continental vertebrate fauna on Earth-to track the evolutionary processes associated with hydrogeographic events over 100 Ma. Net lineage diversification was heterogeneous through time, across space, and among clades. Five abrupt shifts in net diversification rates occurred during the Paleogene and Miocene (between 30 and 7 Ma) in association with major landscape evolution events. Net diversification accelerated from the Miocene to the Recent (c. 20 to 0 Ma), with Western Amazonia having the highest rates of in situ diversification, which led to it being an important source of species dispersing to other regions. All regional biotic interchanges were associated with documented hydrogeographic events and the formation of biogeographic corridors, including the Early Miocene (c. 23 to 16 Ma) uplift of the Serra do Mar and Serra da Mantiqueira and the Late Miocene (c. 10 Ma) uplift of the Northern Andes and associated formation of the modern transcontinental Amazon River. The combination of high diversification rates and extensive biotic interchange associated with Western Amazonia yielded its extraordinary contemporary richness and phylogenetic endemism. Our results support the hypothesis that landscape dynamics, which shaped the history of drainage basin connections, strongly affected the assembly and diversification of basin-wide fish faunas.

Parotocinclus jacksoni, a new hypoptopomatine catfish (Siluriformes: Loricariidae) from the Rio Mamanguape basin, north-eastern Brazil.

A new species of Parotocinclus is described from the Rio Mamanguape basin, in the State of Paraíba, north-eastern Brazil. The new species can be distinguished from all of its congeners, except for P. bahiensis, P. cesarpintoi, P. jumbo, P. nandae and P. spilosoma, by the presence of an abdomen covered by a few small and dispersed platelets (vs. an abdomen entirely covered by large plates in adult individuals or the absence of plates in that region). The new species differs from those mentioned above with respect to several features, such as an exposed pectoral girdle and supporting odontodes medially and laterally, the number of premaxillary and dentary teeth, odontodes covering only the lateral portion of the cleithrum and the absence of irregular golden lines on the head and body (colour in vivo). The new species was collected only in the upper and middle portions of the Rio Mamanguape basin, suggesting a geographic distribution restricted to the Caatinga biome.

Updated checklist and DNA barcode-based species delimitations reveal taxonomic uncertainties among freshwater fishes from the mid-north-eastern Caatinga ecoregion, north-eastern Brazil.

The mid-north-eastern Caatinga is a semiarid freshwater ecoregion in North-eastern Brazil that is dominated by temporary rivers and is currently classified as one of the least ichthyologically-known ecoregions in the world. The present study aimed to provide an updated checklist of mid-north-eastern Caatinga ecoregion (MNCE) freshwater fish species and evaluate their taxonomic identity using morphology, DNA barcoding and multiple species delimitation approaches. After reviewing published studies and ichthyological collections, 119 species were identified. Among these were 94 putatively valid native and 14 non-native species, five undescribed native species, four new records for the MNCE, 11 potential cases of misidentification and 14 species listed as inquirenda. Additionally, 252 individuals from 49 species were barcoded, revealing three potential taxonomic synonyms. The combined molecular approaches estimated a total of 91 native species, although a finalized species list for the MNCE awaits additional taxonomic revisions and field surveys. This study provides the most up-to-date species checklist for the MNCE and a molecular reference database for identifying MNCE fishes with DNA barcodes. Results highlight the need to integrate traditional taxonomy with molecular approaches to correctly identify species, especially in taxonomically problematic ecoregions such as the MNCE.

Spotting mistakes: Reappraisal of Spotted Drum Stellifer punctatissimus (Meek & Hildebrand, 1925) (Teleostei: Sciaenidae) reveals species misidentification trends and suggests latitudinal sexual dimorphism.

A major part of the described species is understudied, falling into the Linnean shortfall. This is a major concern for cryptic species, which require integrative approaches to better evaluate their diversity. We conducted morphological analyses using specimens of Stellifer punctatissimus, S. gomezi, and S. menezesi to reassess their taxonomical identity. We evaluated the allometric and sexual components of the morphology of the Stellifer punctatissimus species complex, and tested and discussed species hypotheses. The combined evidence of our work and previous studies agrees with the current morphological hypothesis of three species, as opposed to the two-lineage molecular hypothesis. However, as cryptic species, they overlap in most their traits, especially females and juveniles. Previously unaccounted variation of allometric and sexually dimorphic characters in this species complex revealed a confounding effect that might explain past and current taxonomic errors. Taxonomical practice of using body depth as a diagnostic character had led to juveniles and females being, respectively, described as a different species or wrongfully identified. Hence, taxonomical studies demand better assessment of allometric and sexual dimorphism components. Herein, we present new characters in a key to the Atlantic species of Stellifer, which disclose size and sexual variation unnoticed in previous studies. The contrasting growth patterns among these species could imply distinct habitat use. As a result, it could be suggested that such species are under different threats, which highlights the need of differential management and conservation strategies.

Molecular delimitation of the seasonal killifishes of the Hypsolebias antenori species group (Cyprinodontiformes, Rivulidae), with description of two new species from the Caatinga coastal basins, northeastern Brazil.

Hypsolebia antenori is a seasonal killifish considered to be broadly distributed along the Caatingas basins of northeastern Brazil, with records in the coastal drainages of the rio Pacoti, rio Jaguaribe, crrego Virglio and rio Apodi-Mossor basins. Based on morphological characters and molecular phylogenetic reconstructions, it was possible to diagnose two new species and restrict H. antenori to the rio Jaguaribe basin. Hypsolebias gongobira new species is described from a temporary pool in the rio Pacoti basin in Cear State, in syntopy with the species threatened H. longignatus. Hypsolebias bonita new species occurs in the floodplains of the rio Apodi-Mossor basin and in the crrego Virglio microbasin in the Furna Feia National Park, in Rio Grande do Norte State. We also discuss the conservation status of these new species and how the So Francisco Interbasin Water transfer, and the agricultural and urban expansion in the semiarid may be adversely affecting these seasonal killifishes.

Redescription of Parotocinclus haroldoi Garavello, 1988 (Siluriformes: Loricariidae), Northeastern Brazil.

Parotocinclus haroldoi is separated from most of its congeners by having an abdomen covered by relatively large plates (vs. naked abdomen or with small plates). This species occurs in Parnaíba River basin with two other congeners, P. cabessadecuia and P. cearensis. Parotocinclus haroldoi is distinguished from P. cabessadecuia for having developed adipose fin (vs. rudimentary or absent adipose fin) and P. cearensis, for having abdomen covered by entirely plates (vs. almost naked abdomen with small sparse plates). Parotocinclus haroldoi is known from the Parnaíba river basin in the state of Piauí, Maranhão-Piauí.

A new species of Characidium (Characiformes: Crenuchidae) from the rio Parnaíba basin, northeastern Brazil.

Characidium tapuia, a new species apparently endemic to the rio Parnaíba basin, Brazil, is described. The new species is easily distinguished from congeners, except C. lanei, C. nana, and C. samurai, by having a broad and conspicuous dark lateral stripe, extending from the tip of snout to the end of caudal peduncle and by the absence of dark vertical bars on body of specimens larger than 23.0 mm SL. Characidium tapuia differs from the aforementioned species by a series of features, including 12 circumpeduncular scales (vs. 13 or 14 in C. lanei and C. samurai), presence of parietal branch of the supraorbital canal (vs. absence in C. lanei and C. nana), complete lateral line and adipose fin present (vs. lateral line incomplete and adipose fin absent in C. nana), and midlateral stripe with irregular borders (vs. lateral stripe with overall straight borders in C. samurai).

Phenacorhamdia cabocla, a new heptapterid from the Parnaíba River basin, Northeastern Brazil (Siluriformes: Heptapteridae).

Phenacorhamdia Dahl, 1961 comprises 11 valid species of small demersal and solitary catfishes which occur mainly along riverbeds and are widely distributed throughout rivers of South America. The genus is included within the Nemuroglanis subclade, and species of Phenacorhamdia can be separated from other heptapterid catfishes through external and internal characters. Diagnostic characters include a prognathous mouth, first ray of dorsal and pectoral fins flexible, eight or nine branched rays in the lower lobe of caudal fin, and optic foramen reduced. A new species of Phenacorhamdia is described herein from the upper Parnaíba river basin. Phenacorhamdia cabocla sp. nov is distinct from its congeners by: total vertebrae 44, nine of which with pleural ribs; bifid neural spines until vertebrae 13; last precaudal vertebrae lacking pleural ribs; 7-8 branchiostegal rays; pectoral-fin rays i+6; first pterygiophore of dorsal-fin associated to the neural spine of twelfth vertebrae; dorsal-fin pterygiophores associated to vertebrae 12 to 16; anal-fin with nine branched and 3-4 unbranched rays; upper and lower lobes of caudal fin with 8-9 branched rays each; adipose fin corresponding to 14.9%-18.1% of standard length; and snout length corresponding to 30.0%-35.9% of head length.

Filling in a biogeographic gap: the first Trichomycteridae from the Parnaíba River basin (Siluriformes: Trichomycteridae)

Trichomycterid catfishes have long been considered as absent in the Parnaíba River basin, Northeastern Brazil, in what constitutes their most conspicuous gap in geographic distribution. Herein we report on the first occurrence of the family in that basin. The new species is described from the riacho da Volta, right tributary to the upper rio Parnaíba, Piauí State. It is distinguished from its congeners by the combination of two or three pairs of ribs; 36­38 post Weberian vertebrae; a color pattern composed of round, similar-sized, non-coalescent spots; I,5 pectoral-fin rays; the first haemal arch on the 5th or 6th vertebrae; and the first completely fused (to the tip) haemal spine on the 15th vertebra. A putative autapomorphy is the partial (minimally 50% of their length) or total fusion between the anterior arms of the basipterygium. Preliminary evidence suggests that the new species can be related to northern South American forms, a pattern that fits the general Amazonian relationships of the fishes in the Parnaíba River drainage. Although the new species fills in an important qualitative gap in trichomycterid continental distribution, the taxon is apparently rare and extremely restricted in distribution, with the type series being its only record so far. The paucity of trichomycterids in the Parnaíba remains a puzzling biogeographical phenomenon.(AU)

Os bagres tricomicterídeos têm estado surpreendentemente ausentes na bacia do rio Parnaíba, Nordeste do Brasil, no que constitui sua lacuna mais evidente na distribuição. Relatamos a primeira ocorrência da família na bacia. A espécie nova é descrita do riacho da Volta, tributário do lado direito do alto rio Parnaíba em Uruçuí, Piauí. Ela é distinguida de suas congêneres pela combinação de dois ou três pares de costelas; 36­38 vértebras pós weberianas; padrão de coloração composto de manchas arredondas, de tamanhos semelhantes e não coalescentes; I,5 raios nas nadadeiras peitorais; o primeiro arco haemal na 5° ou 6° vértebra, e o primeiro espinho haemal completamente fusionado (até a extremidade) na 15° vértebra. Uma possível autapomorfia é a fusão parcial (mínimo de 50% do seu comprimento) ou total entre os braços anteriores do basiopterígio. Evidências preliminares sugerem que a espécie nova pode estar relacionada com as formas do norte da América do Sul, padrão que se encaixa nas relações amazônicas dos peixes da drenagem do rio Parnaíba. Embora a espécie nova preencha uma importante lacuna na distribuição continental dos tricomicterídeos, o táxon é aparentemente raro e extremamente restrito em distribuição, sendo a série-tipo seu único registro até o momento.(AU)

Description of three new species of Eigenmannia (Gymnotiformes: Sternopygidae) from the rio Mearim and rio Parnaíba basins, Northeastern Brazil

Three new species of Eigenmannia belonging to the E. trilineata species-group are described. The first species is described from rio Mearim basin and can be diagnosed by lateral line stripe restricted to last two thirds of body, superior midlateral stripe present, 176-205 anal-fin rays, 10-15 scales rows above lateral line, 109-125 lateral line scales, 19-23 premaxillary teeth, 20-29 dentary teeth, 6-10 endopterygoid teeth, and 13-14 precaudal vertebrae. The second species is described from upper rio Parnaíba, and can be diagnosed by lateral line stripe restricted to last two-thirds of body, ii,11-13 pectoral-fin rays, 180-196 anal-fin rays, 12-15 scales rows above lateral line, 10-14 premaxillary teeth, 15-21 dentary teeth, 8-10 endopterygoid teeth, and 14 precaudal vertebrae. The third species is widespread in rio Parnaíba basin, and can be diagnosed by absence of lateral line stripe, absence of superior midlateral stripe, 182-228 anal-fin rays, 12-15 scales rows above lateral line, 107-131 lateral line scales, 32-34 premaxillary teeth, 35-44 dentary teeth, 9-12 endopterygoid teeth, and 13 precaudal vertebrae. A dichotomous key and the conservation status for the three species are provided.(AU)

Três espécies novas de Eigenmannia pertencentes ao grupo E. trilineata são descritas. A primeira espécie é descrita para a bacia do rio Mearim e pode ser diagnosticada por apresentar faixa da linha lateral restrita aos últimos dois terços do corpo, faixa médio lateral superior presente, 176-205 raios na nadadeira anal, 10-15 fileiras de escamas acima da linha lateral, 109-125 escamas na linha lateral, 19-23 dentes pré-maxilares, 20-29 dentes no dentário, 6-10 dentes no endopterigóide, e 13-14 vértebras pré-caudais. A segunda espécie é descrita do alto rio Parnaíba, e pode ser diagnosticada por apresentar faixa da linha lateral restrita aos últimos dois terços do corpo, ii,11-13 raios na nadadeira peitoral, 180-196 raios na nadadeira anal, 12-15 fileiras de escamas acima da linha lateral, 10-14 dentes pré-maxilares, 15-21 dentes no dentário, 8-10 dentes no endopterigóide, e 14 vértebras pré-caudais. A terceira espécie está amplamente distribuída na bacia do rio Parnaíba, e pode ser diagnosticada pela ausência de faixa na linha lateral, ausência da faixa médio lateral superior, 182-228 raios na nadadeira anal, 12-15 fileiras de escamas acima da linha lateral, 107-131 escamas na linha lateral, 32-34 dentes pré-maxilares, 35-44 dentes no dentário, 9-12 dentes no endopterigóides, e 13 vértebras pré-caudais. Uma chave dicotômica e o status de conservação para as três espécies são fornecidas.(AU)

Review of the armoured catfish genus Hypostomus (Siluriformes: Loricariidae) from the Parnaíba River basin, Northeastern Brazil, with description of a new species

The species of Hypostomus from the Parnaíba River basin were reviewed through molecular and morphological analysis. Five species were found in the basin, including a new species herein described. The distribution of H. pusarum was expanded to this basin, and a closely related species was recorded (H. aff. pusarum), also the presence of H. johnii and H. vaillanti was confirmed. The new species is distinguished from most congeners by its large number of premaxillary and dentary teeth, a wide dental angle of 115° to 135°, presence of a rounded dark spots on a lighter background and anteromedial region of the abdomen depleted of plaques (vs. anteromedial region of the abdomen covered by platelets and odontodes in H. johnii, H. pusarum, H. aff. pusarum and H. vaillanti). Furthermore, an identification key of the species from the Maranhão-Piauí ecoregion and maps with the geographic distribution of these species are presented. The species of Hypostomus in the Parnaíba River basin have different geographic distributions, suggesting different niches or geographical barriers, providing an opportunity for ecological and evolutionary studies.(AU)

As espécies de Hypostomus da bacia do rio Parnaíba foram revisadas por meio de análises moleculares e morfológicas. Cinco espécies foram encontradas na bacia, incluindo uma nova espécie aqui descrita. A distribuição de H. pusarum foi expandida para esta bacia, uma espécie intimamente relacionada foi registrada (H. aff. pusarum), e a presença de H. johnii e H. vaillanti foi confirmada. A nova espécie se distingue da maioria das congêneres por seu grande número de dentes nos pré-maxilares e dentários, um amplo ângulo do dentário de 115° a 135°, presença de manchas escuras arredondadas em um fundo mais claro e região anteromedial do abdômen sem placas (vs. região anteromedial do abdômen coberta por placas e odontódios em H. johnii, H. pusarum, H. aff. pusarum e H. vaillanti). Além disso, é apresentada uma chave de identificação das espécies da ecorregião Maranhão-Piauí e mapas com a distribuição geográfica dessas espécies. As espécies de Hypostomus na bacia do rio Parnaíba apresentam diferentes distribuições geográficas, sugerindo diferentes nichos ou barreiras geográficas, proporcionando oportunidade para estudos ecológicos e evolutivos.(AU)

Ichthyofauna of Ceará-Mirim River basin, Rio Grande do Norte State, northeastern Brazil.

Ichthyological studies in coastal basins of the Mid-Northeastern Caatinga ecoregion were first conducted in the early 20th century, including collections from the Ceará-Mirim River basin, in northeastern Brazil. Besides a few systematics and ecological studies, the knowledge on fishes from this watershed is still considered partial and restricted to the freshwater portion. Thus, the objective of this paper was to conduct a comprehensive ichthyological survey of the entire Ceará-Mirim River basin, from the headwaters to the estuarine area. Fish surveys were conducted from 2011 to 2016 using varied fishing gear, resulting in the record of 63 native species (24 freshwater, 15 estuarine, and 24 marine species) and two introduced species. Four species are putatively endemic to the ecoregion, and 48 consist of new records for the basin. According to the Brazilian's threatened fish list, three species are currently classified as 'vulnerable' (Megalops atlanticus, Hippocampus reidi and Mycteroperca bonaci), four as 'near threatened' (Kryptolebias hermaphroditus, Dormitator maculatus, Lutjanus sygnagris and L. jocu) and three as 'data deficient' (Cheirodon jaguaribensis, Mugil curema and Sphoeroides testudineus). The Ceará-Mirim River basin does not have any protected areas and has been suffering multiple anthropogenic impacts, however the "Centro Tecnológico de Aquicultura" (Aquaculture Technological Center) of the Universidade Federal do Rio Grande do Norte (CTA/UFRN) at the lower portion of the basin may help in the conservation of the estuarine and estuarine fish species.

A new species of Parotocinclus with reduced adipose fin (Loricariidae: Hypoptopomatinae), from the rio Jacuípe basin, Bahia State, Brazil

A new species of Parotocinclus, apparently endemic to the rio Jacuípe basin, Bahia State, Brazil, is described. The new species is distinguished from congeners, except P. bidentatus, P. cabessadecuia, P. dani, P. halbothi, P. muriaensis, P. pentakelis, P. seridoensis, and P. spilurus, by the presence of a reduced adipose fin. The new species differs from the aforementioned species by the absence of unicuspid accessory teeth, abdomen with broad naked areas between lateral and medial patches of plates, and snout tip completely covered by plates and odontodes. The adipose fin of the new species is restrict solely to the adipose-fin spine, lacking the adipose-fin membrane, a reduction pattern previously described to P. halbothi, a congener from rivers of the Amazonas and Marowijne basins.(AU)

Uma espécie nova de Parotocinclus, aparentemente endêmica da bacia do rio Jacuípe, Estado da Bahia, Brasil, é descrita. A espécie nova se distingue de suas congêneres, exceto P. bidentatus, P. cabessadecuia, P. dani, P. halbothi, P. muriaensis, P. pentakelis, P. seridoensis e P. spilurus, pela presença de nadadeira adiposa reduzida. A nova espécie difere das espécies mencionadas anteriormente pela ausência de dentição acessória unicúspide, abdômen com amplas áreas nuas entre o grupo de placas laterais e o grupo de placas medianas e ponta do focinho completamente coberta por placas e odontódeos. A nadadeira adiposa da nova espécie é restrita somente ao espinho, sem a membrana da adiposa, um padrão de redução descrito para P. halbothi, uma congênere de rios da bacia Amazônica e da bacia do rio Marowijne.(AU)

Freshwater fish richness baseline from the São Francisco Interbasin Water Transfer Project in the Brazilian Semiarid

Among Neotropical freshwater ecoregions, the Mid-Northeastern Caatinga (MNCE) is a fish knowledge gap. Its temporary drainages are receptors of the São Francisco interbasin water transfer project (SFR-IWT) in the Brazilian semiarid. We provide a comprehensive baseline of fish richness of the five SFR-IWT basins. Species richness, shared, endemic, threatened and non-native species were obtained using sampling, ichthyologic collections, literature and online repositories (306 localities). In total 121, species were recorded, 111 of them native, and 16 (14.41%) listed for all basins. Higher richness of native species (78, 70.27%) was recorded in the São Francisco lower-middle stretch (SFRE), including 23 endemic, 61 (54.95%) in MNCE basins (13 endemic), and 28 (25.23%) shared between both ecoregions. In the MNCE, 50 species were recorded in Jaguaribe (JAG), 39 in Piranhas-Açu, 36 in Paraíba do Norte, and 32 in Apodi-Mossoró (APO). The number of species shared between the SFRE and each receptor basin varied from 24 (23.08%, JAG) to 20 (22.22%, APO). JAG contains 81.97% of the receptor basins' species. Its higher richness and endemism deserve special attention regarding the ongoing hydrological changes. This study will help detect possible modifications in the ichthyofauna of the main MNCE drainages.(AU)

Dentre as ecorregiões dulcícolas neotropicais, a Nordeste Médio-Oriental (MNCE) é uma lacuna de conhecimento sobre peixes. Suas drenagens temporárias são receptoras do projeto de transposição do São Francisco (SFR-IWT) no semiárido brasileiro. Fornecemos uma linha de base abrangente da riqueza de peixes das cinco bacias do SFR-IWT. Riqueza de espécies, espécies compartilhadas, endêmicas, ameaçadas e não-nativas foram obtidas através de amostragem, coleções ictiológicas, literatura e repositórios online (306 localidades). No total, foram registradas 121 espécies, 111 nativas e 16 (14,41%) listadas para todas as bacias. A maior riqueza de espécies nativas (78, 70,27%) foi registrada no trecho sub-médio do São Francisco (SFRE), incluindo 23 endêmicas e 61 (54,95%) nas bacias da MNCE (13 endêmicas), e 28 (25,23 %) compartilhadas entre ambas ecorregiões. Na MNCE, foram registradas 50 espécies na Jaguaribe (JAG), 39 na Piranhas-Açu, 36 na Paraíba do Norte e 32 na Apodi-Mossoró (APO). O número de espécies compartilhadas entre SFRE e cada bacia receptora variou de 24 (23,08%, JAG) a 20 (22,22%, APO). JAG contém 81,97% das espécies das bacias receptoras. Sua maior riqueza e endemismo merecem atenção especial em relação às mudanças hidrológicas em curso. Este estudo ajudará a detectar possíveis modificações na ictiofauna das principais drenagens da MNCE.(AU)

Ichthyofauna of the Mamanguape river basin, Northeastern, Brazil / Ictiofauna da bacia do rio Mamanguape, Nordeste, Brasil

Abstract: The Mamanguape River Basin is located in a peripheral semi-arid area of South America, with its headwaters and middle reaches running through the Caatinga (from wetter to drier) and its lower reaches through the Atlantic Forest. The objective of this study was to inventory the fish fauna of the Mamanguape river basin through a comprehensive sampling and to discuss its ichthyofaunal dominance pattern. Sampling was conducted between 2015 and 2016 at 38 points throughout. The main river course was sampled at 18 fixed points during two expeditions (dry and wet seasons) using traw nets, cast nets, and dip nets, with a standardized effort. The tributaries were sampled during the dry season at 20 points using an adaptaptation of the AquaRAP methodology. A total of 32 freshwater fish species belonging to 26 genera, 16 families and six orders were recorded, predominantly from the order Characiformes and the family Characidae. Astyanax fasciatus had widest distribution and greatest abundance in the basin. Siluriformes were the second most prevalent order, with five species recorded. Cichla cf. monoculus, Poecilia reticulata and Oreochromis niloticus were non-native records for the basin. Apareiodon davisi, an Endangered species, was recorded.

Resumo: A bacia do rio Mamanguape está situada numa área periférica do semiárido, suas nascentes e porção média correndo em área de domínio da Caatinga - de mais úmida a mais seca, e sua porção baixa em área de Mata Atlântica. O estudo teve por objetivo inventariar a fauna de peixes da bacia do rio Mamanguape, através de uma amostragem abrangente de suas drenagens, e discutir o padrão de dominância de sua ictiofauna. O trabalho de coleta foi realizado entre os anos de 2015 e 2016, em 38 pontos distribuídos em toda a bacia. Dezoito pontos foram amostrados ao longo do curso principal do rio (Pontos Fixos), em duas expedições (seca e cheia), através de arrasto, tarrafa e puçá, com esforço padronizado. Os afluentes foram amostrados durante a estação seca, em 20 pontos, utilizando-se uma adaptação da metodologia AquaRap. Foram registradas 32 espécies de peixes de água doce pertencentes a 26 gêneros, 16 famílias e seis ordens, com predominância da ordem Characiformes e da família Characidae, sendo Astyanax fasciatus a espécie de maior distribuição e abundância na bacia. Siluriformes foi a segunda ordem de maior predominância, com cinco espécies. Cichla cf. monoculus, Oreochromis niloticus e Poecilia reticulata constituíram registros de introdução na bacia; foi registrada Apareiodon davisi, uma espécie ameaçada de extinção (Em Perigo).

Continental ichthyofauna from the Paraíba do Norte River basin pre-transposition of the São Francisco River, Northeastern Brazil / Ictiofauna continental da bacia do Rio Paraíba do Norte pré-transposição do rio São Francisco, Nordeste do Brasil

Abstract: Freshwater ichthyofauna from Brazil Northeast region was considered as being poorly known until recent years, with a considerable number of publications becoming available in the last decade. The present study provides an inventory of freshwater fish species from the Paraíba do Norte River basin located in Paraíba State, Brazil. This inventory is intended to contribute to the of knowledge to the regional fish diversity, pre-transposition of the São Francisco River. Collecting data was obtained from ichthyological databases of both national and foreign institutions. A total of 47 freshwater fish species are registered within the Paraíba do Norte River basin, represented by 38 genera, 20 families and six orders. Characiformes, comprising 47% (22 species), Cichliformes, and Siluriformes are among the most representative orders, 19% (9 species) each, of total recorded species. Seven species of Cichliformes are reported as introduced species in this basin. Cyprinodontiformes and Gobiiformes also registered in this region and correspond to 5% (two species) and Gymnotiformes, Perciformes and Synbranchiformes, 2% (one species each) of total recorded species. Paraíba do Norte River basin stands out in the current national scenario as it comprises the first region from the Mid-Northeastern Caatinga freshwater ecoregion to receive water from the transposition of the São Francisco River. The current inventory is important as it provides scientific data related to the ichthyofauna of Paraíba do Norte River basin prior to the commencement of the river transposition process. An identification key is also given for the freshwater fish species of the region.

Resumo: A ictiofauna de água doce do Nordeste brasileiro durante muito tempo foi considerada pouco conhecida. No entanto, este paradigma vem sendo mudado nas últimas décadas com aumento significativo no número de publicações desta ictiofauna. Para contribuir com mais informações sobre a diversidade de peixes do Nordeste brasileiro, o presente estudo realizou um inventário das espécies de peixes de água doce da bacia do rio Paraíba do Norte, localizada no Estado da Paraíba, pré-transposição do Rio São Francisco. Os dados foram provenientes de acervos ictiológicos de instituições nacionais e estrangeiras. Foram registradas 47 espécies, distribuídas em 38 gêneros, 20 famílias e seis ordens de peixes na bacia do rio Paraíba do Norte. As ordens mais representativas foram Characiformes (22 espécies/47% do total), Cichliformes e Siluriformes (9/19%). Sete espécies de Cichliformes são reportadas como introduzidas na bacia. Além das ordens citadas, foram registrados dois Cyprinodontiformes and Gobiiformes (2/5%), e Gymnotiformes, Perciformes e Synbranchiformes (1/2% cada). A bacia do Paraíba do Norte tem se destacado no cenário atual por ser a primeira da região Nordeste Médio-Oriental a receber águas da transposição do rio São Francisco. Com isso, este inventário é de fundamental importância, por apresentar dados da ictiofauna da bacia do rio Paraíba do Norte antes da transposição. Esse trabalho também apresenta uma chave para identificação das espécies de peixes da bacia.

Ichthyofauna of the Nascentes do Rio Parnaíba National Park: watershed divide in the main agricultural encroachment area in the Brazilian Cerrado / Ictiofauna do Parque Nacional Nascentes do Rio Parnaíba: um divisor de bacias hidrográficas na principal área de expansão agrícola do Cerrado Brasileiro

The Nascentes do Rio Parnaíba National Park (NPNP), located in Brazilian Cerrado, protects portions of three river basins: headwaters of Parnaíba, a small portion in upper Tocantins-Araguaia, and tributaries of the middle section of the São Francisco. This protected area is in the boundaries of the states of Maranhão, Tocantins, Piauí, and Bahia, also known as MATOPIBA, a region that has established rapid agricultural expansion associated to land conflicts between corporate agriculture, family agriculture, protected areas, indigenous territories, and quilombola communities. The knowledge of the ichthyofauna in this region is scarce while the impacts on the aquatic environments are increasing. We made a survey of fishes in the NPNP and its surroundings areas, estimating richness, endemics, introduced and shared species between river basins. During 2014, 54 sampling sites were visited, 19 in the NPNP and 35 in the surrounding area. Ninety-five species, 51 genera, 22 families, and six orders were recorded, of which 38 (40%) are in the NPNP. One introduced species were recorded in the Parnaíba River basin and no endangered species were registered. Our data corroborate the importance of the network of protected areas for the preservation of Cerrado fishes, including some possibly undescribed and restricted-range species that may be threatened due to intense agricultural encroachment in the MATOPIBA region.

O Parque Nacional Nascentes do Rio Parnaíba (PNNP), localizado no Cerrado brasileiro, protege diferentes porções de três bacias hidrográficas, as cabeceiras do Parnaíba, uma pequena porção do alto rio Tocantins e tributários do trecho médio do São Francisco. Esta área protegida está localizada nos limites dos estados do Maranhão, Tocantins, Piauí e Bahia, também conhecida como MATOPIBA, região que tem apresentado rápida expansão agrícola associada a conflitos fundiários do agronegócio com agricultura familiar, áreas protegidas, territórios indígenas e comunidades quilombolas. O conhecimento da ictiofauna nessas regiões é escasso, embora os impactos sobre os ecossistemas aquáticos sejam crescentes. Assim, elaboramos um levantamento de peixes do PNNP e em seu entorno, identificando a riqueza, espécies endêmicas, introduzidas e compartilhadas entre bacias hidrográficas. Durante o ano de 2014 foram visitados 54 locais de amostragem, 19 no PNNP e 35 no entorno. Foram coletadas 95 espécies, 51 gêneros, 22 famílias e seis ordens, das quais 38 espécies (40%) estão no PNNP. Uma espécie introduzida foi registrada na bacia do rio Parnaíba e nenhuma espécie ameaçada de extinção foi registrada. Os dados aqui apresentados corroboram a importância da rede de áreas protegidas para a preservação dos peixes do Cerrado, com espécies potencialmente novas e de distribuição restrita, que podem estar ameaçadas devido à intensa expansão agrícola na região do MATOPIBA.

A new species of armored catfish Parotocinclus (Siluriformes: Loricariidae) from the rio Parnaíba basin, northeastern, Brazil

Recent taxonomic studies indicated the presence of several undescribed species in the rio Parnaíba basin. Among those, a new species of Parotocinclus endemic of this drainage is herein described. It differs from most of its congeners, including the sympatric P. haroldoi and P. cearensis, by a vestigial or rudimentary adipose fin (vs. conspicuous adipose fin). This character is also present in P. bidentatus and P. muriaensis (both from the rio Paraíba do Sul basin, southeastern Brazil), P. spilurus (rio Jaguaribe basin, northeastern Brazil), P. seridoensis (rio Piranhas-Açu basin, northeastern Brazil), P. halbothi (rios Trombetas and Marowijne basins, northern Brazil and Suriname) and P. dani (from rio Tapajós in Mato Grosso State, Brazil). The new species differs from these latter species mainly by the abdomen extensively covered by broad dermal plates. It also differs from P. haroldoi and P. cearensis by light bands between the snout tip and the nostrils.(AU)

Estudos taxonômicos recentes indicaram a presença de várias espécies não descritas na bacia do rio Parnaíba. Dentre estas, uma nova espécie de Parotocinclus endêmica desta drenagem é aqui descrita. Ela difere da maioria dos seus congêneres, incluindo as simpátricas P. haroldoi e P. cearensis, por apresentar nadadeira adiposa vestigial ou rudimentar (vs. nadadeira adiposa desenvolvida). Este caráter também está presente em P. bidentatus e P. muriaensis (ambos do rio Paraíba do Sul, sudeste do Brasil), P. spilurus (bacia do rio Jaguaribe, nordeste do Brasil), P. seridoensis (bacia do rio Piranhas-Açu, nordeste do Brasil), P. halbothi (bacias dos rios Trombetas e Marowijne, norte do Brasil e no Suriname) e P. dani (do rio Tapajós no Estado do Mato Grosso, Brasil). A nova espécie difere destas principalmente pelo abdômen extensivamente coberto por placas dérmicas largas. Também difere de P. haroldoi e P. cearensis pela presença de faixas claras entre a ponta do focinho e as narinas.(AU)

Ichthyofauna of Mundaú river basin, Ceará State, Northeastern Brazil / Ictiofauna da bacia do rio Mundaú, Estado do Ceará, Nordeste do Brasil

Abstract Mundaú river basin is located at Center-North Ceará State and occupies a total area of 2,227 km2, including Estuário do Rio Mundaú Environmental Protection Area. This study aimed to catalog the fishes of this basin. Collections were performed with active and passive gear in 35 sampling sites, between 2012 and 2014, in several habitats (main channels, streams, floodplains, permanent and temporary pools, ponds, and dams). A total of 2,545 specimens were collected, belonging to 55 species distributed in 10 orders, 31 families, and 50 genera; 30 of these are strictly freshwater species, and 25 estuarine-marine species. Three species (Hemigrammus guyanensis Gery, 1995, H. rodwayi Durbin, 1909 and Poecilia sarrafae Bragança & Costa, 2011) represent new records for the Mid-Northeastern Caatinga ecoregion. Besides, two cynolebiid species, Hypsolebias sp. and Anablepsoides cearensis (Costa & Vono, 2009), were found and the latter, currently classified as critically endangered, had its occurrence area widened.

Resumo A bacia do Rio Mundaú está situada no centro-norte do Estado do Ceará, e drena uma área de 2.227 km2 de Caatinga, incluindo a Área de Proteção Ambiental do Estuário do Rio Mundaú. Este estudo teve como objetivo realizar um inventário dos peixes desta bacia. As coletas foram realizadas com petrechos ativos e passivos, em 35 pontos amostrais entre 2012 e 2014 em diversos habitats (canal principal, córregos, alagados, poças permanentes e temporárias, lagoas e açudes) ao longo de toda a bacia. Um total de 2.545 indivíduos foram coletados, pertencentes a 55 espécies distribuídas em 10 ordens, 31 famílias e 50 gêneros; destas, 30 são estritamente de água doce e 25 estuarino-marinhas. Três espécies (Hemigrammus guyanensis Gery,1995, H. rodwayi Durbin, 1909 e Poecilia sarrafae Bragança & Costa, 2011) constituem novas ocorrências para a ecorregião do Nordeste Médio-Oriental. Além disso, foram registradas duas espécies de cinolebídeos, Hypsolebias sp. e Anablepsoides cearensis (Costa & Vono, 2009), a última classificada como criticamente ameaçada de extinção, teve sua área de ocorrência ampliada.

Composition of the ichthyofauna in Brazilian semiarid reservoirs / Composição da ictiofauna em reservatórios do semiárido brasileiro

Abstract The scale of impact that the São Francisco River transposition project will have on the drainage basins ichthyofauna is still unclear, however, changes in the fish community diversity and abundance is probable. Surveys and registries of the fish fauna within key systems of the catchment basins are priority actions for the conservation of the aquatic diversity. This study conducted a taxonomic survey of the Epitácio Pessoa (Boqueirão municipality) and Argemiro de Figueiredo (Itatuba municipality), reservoirs ichthyofauna, both belonging to the Paraíba do Norte River basin, important socioeconomic and environmental systems for the transposition project. Monthly sampling was carried out between October/2014 to September/2015 in the upstream and downstream zones of the reservoirs. The specimens were collected using dip nets, drag nets, and sieves, and placed on ice in the field. Later in the laboratory, they were transferred to 10% formaldehyde and then preserved in 70% alcohol. A total of 2,328 specimens were collected representing five orders, 14 families, and 31 species in both systems. At the upstream zones 2057 specimens were collected representing 17 species, and at the downstream zones 271 specimens were collected representing 24 species. Of the 31 species recorded, 13 species are endemic to watersheds that drain rivers from the Brazilian semi-arid region, and seven species (Apareiodon davisi, Characidium bimaculatum, Hypostomus pusarum, Parotocinclus jumbo, P. spilosoma, Pimelodella enochi, and Prochilodus brevis) are endemic to the Mid-Northeastern Caatinga Ecoregion (MNCE). Among the latter, Parotocinclus spilosoma and Pimelodella enochi are endemic to the Paraíba do Norte River. Apareiodon davisi is classified as Endangered according to the current published Brazil's official list of endangered species of fish and aquatic invertebrates. This pre-transposition ichthyofaunistic survey will serve as a basis for future post-transposition analyzes, considering this action will change the scope of the ecosystems diversity.

Resumo A dimensão do impacto que a transposição do rio São Francisco provocará na ictiofauna das bacias receptoras ainda é imprecisa, entretanto, é provável que haja alterações na riqueza e abundância da comunidade de peixes. Levantamentos e registros prévios da fauna íctica em sistemas chaves das bacias receptoras são ações prioritárias para a conservação da diversidade aquática. Este estudo realizou o levantamento taxonômico da ictiofauna dos reservatórios Epitácio Pessoa (município de Boqueirão), e Argemiro de Figueiredo (município Itatuba), ambos pertencentes a bacia hidrográfica do rio Paraíba do Norte, estado da Paraíba, importantes sistemas sócioeconômicos e ambientais para o projeto da transposição. Assim, foram realizadas amostragens mensais de Outubro/2014 a Setembro/2015 nas zonas lacustres e a jusante dos reservatórios. Os espécimes foram coletados com redes de espera, tarrafa, arrasto, peneiras e puçás, em seguida acondicionados em gelo no campo, posteriormente no laboratório, transferidos para o formol a 10% e conservados em álcool 70%. Foram coletados um total de 2328 espécimes distribuídas em 31 espécies, 14 famílias e cinco ordens nos dois sistemas. Nas zonas lacustres foram coletados 2057 espécimes distribuídos em 17 espécies e nas áreas a jusantes foram coletados 271 indivíduos, distribuídos em 24 espécies. Das 31 espécies registradas, 13 são endêmicas das bacias hidrográficas que drenam rios do semiárido brasileiro, destas, sete (Apareiodon davisi, Characidium bimaculatum, Hypostomus pusarum, Parotocinclus jumbo, P. spilosoma, Pimelodella enochi e Prochilodus brevis) são endêmicas do Nordeste Médio Oriental. Dentre estas últimas, P. spilosoma e Pimelodella enochi são endêmicas do rio Paraíba do Norte. Apareiodon davisi é classificada como Em Perigo de acordo com a atual lista oficial de espécies ameaçadas de peixes e invertebrados aquáticos no Brasil. Este levantamento ictiofaunístico pré-transposição servirá de base para análises futuras pós-transposição, considerando que esta ação acarretará mudanças no âmbito de diversidade dos ecossistemas em questão.