Taxonomic revision of the Ophidion holbrookii Putnam, 1874 (Ophidiiformes: Ophidiidae) species complex, with description of a new species from Brazil.

This study integrates morphological and molecular data to redefine the taxonomic limits of Ophidion holbrookii, as well as its geographic ranges, with the description of a new species from the eastern and southeastern coast of Brazil, South America. Ophidion zavalai n. sp. is described based on variations related to ontogeny and sexual development of swim bladder and sonic apparatus, which are likely important traits for species recognition. The description of O. zavalai n. sp. and the redefinition of distribution limits of O. holbrookii corroborate the existence of different complex species in the western Atlantic, revealing important gaps of knowledge regarding morphological variation and species habits. Ophidion zavalai n. sp. is the first species of Ophidion described from the southwestern Atlantic Ocean and contributes to evidence of a distinct coastal fauna in Brazil and surrounding areas of Argentina province.

Review of the Pareques acuminatus (Bloch & Schneider, 1801) species complex, with revalidation of Pareques lineatus (Cuvier, 1830) from the Western Atlantic (Percomorphacea: Sciaenidae).

Recently, different studies have revealed the existence of complexes of marine fish species of several genera from the Western Atlantic (e.g., Bagre, Peprilus, Bairdiella, Pogonias and Menticirrhus), with a correspondence between recognized species and well-established geographic areas such as the Gulf of Mexico, the Caribbean, and Brazil, showing the need to improve the taxonomic knowledge of coastal fishes in the region. In this work, we revalidate and redescribe Pareques lineatus (Cuvier, 1830) described from Brazil, and redescribe and designate a neotype to P. acuminatus (Bloch & Schneider, 1801) to differentiate it properly from its congeners. The recognition of P. acuminatus for the east coast of the USA plus the Gulf of Mexico and of P. lineatus for Brazil, with the West Indies and southern Caribbean as an area of overlap, brings new information about biodiversity in Western Atlantic coastal areas and confirms a previously proposed major biogeographical boundary.

Molecular identification of Brachygenys and Haemulon species (Perciformes: Haemulidae) from the Brazilian coast

The fishes of the Haemulidae family are currently allocated to 19 genera with a worldwide distribution in the tropical and subtropical waters of the world's oceans. Brachygenys and Haemulon are important genera of reef fish in Brazil, as they occur in large shoals, which are both ecologically and commercially valuable. This study identified the Brazilian species of the genera Brachygenys and Haemulon using DNA barcodes. While we found only a single lineage in Brachygenys chrysargyrea, Haemulon melanurum, H. parra, and H. squamipinna, more than one molecular operational taxonomic unit (MOTU) was identified in H. atlanticus, H. aurolineatum, and H. plumieri, indicating the possible existence of discrete populations or cryptic species.(AU)

Os peixes da família Haemulidae estão atualmente distribuídos em 19 gêneros, com distribuição mundial em águas oceânicas tropicais e subtropicais. Brachygenys e Haemulon são importantes gêneros de peixes recifais do Brasil, visto que ocorrem em grandes cardumes, de valores ecológicos e comerciais. Este estudo identificou as espécies brasileiras dos gêneros Brachygenys e Haemulon usando o código de barras de DNA. Embora apenas uma única linhagem de Brachygenys chrysargyrea, Haemulon melanurum, H. parra e H. squamipinna tenha sido encontrada em nosso conjunto de dados, mais de uma unidade taxonômica operacional molecular (MOTU) foi identificada em H. atlanticus, H. aurolineatum e H. plumieri, indicando a possível existência de populações discretas ou espécies crípticas.(AU)

Taxonomic revision of the Menticirrhus americanus (Linnaeus, 1758) and M. littoralis (Holbrook, 1847) (Percomorphacea: Sciaenidae) species complexes from the western Atlantic.

The genus Menticirrhus is widely distributed in the Neotropical region, where its species are common and abundant in shallow coastal waters and estuaries. The diversity, biogeography, and evolutionary relationships of the Menticirrhus species are still poorly known, due primarily to the difficulty of differentiating the species, given the broad similarities in their external morphology. The present study is based on the analysis of morphological and molecular data, with the examination of type specimens and a comprehensive collection of non-type specimens from an ample geographic range. These analyses indicated that two widely distributed Western Atlantic species, Menticirrhus americanus and M. littoralis, represent species complexes. The M. littoralis species complex is characterized by the absence of dark bars on body side, and a smaller, light-colored pectoral fins, that barely reaching the tip of the depressed pelvic fins, with fewer pectoral-fin rays. This complex includes three species: M. littoralis, found in the Gulf of Mexico, M. gracilis, from the southeastern and southern coast of South America, and a new species, described here, from the northern to eastern Brazilian coast. The M. americanus species complex is characterized by the presence of dark bars on body side, and a large, dark pectoral fin, that surpass the tip of the depressed pelvic fin, with more pectoral-fin rays. This complex has two species, M. americanus, which occurs on the east coast of the United States and in the Gulf of Mexico, and M. martinicensis, found from Caribbean to Argentina, that represents a cryptic allopatric species. An identification key to all species of the genus is presented.

The deep sea teleost fish fauna of the Brazilian North Coast

Data on the deep sea fishes found off the northern Brazilian coast are restricted to the results of the surveys of the RV Oregon, a research vessel of the North American National Marine Fisheries Service, and the REVIZEE Program. The REVIZEE Score-Norte Program focused on commercial fish species and natural resources with potential for exploitation on the continental shelf and slope off the northern coast of Brazil. In this sense, the REVIZEE Score-Norte Program generated little information on species of no commercial value, did not catalog its inventory in zoological collections, and did not publish species lists. Given this considerable knowledge gap on the deep-sea fish found off the North coast of Brazil, we compiled all the available data on the deep-sea fish of this region and also retrieved photographic records from the REVIZEE Score-Norte Program, including the PRODEMERSAL and PROTUNA projects. Considering the published records, specimens deposited in zoological collections, and the interpretation of photographic records, we compiled a list of 63 species of deep-sea fish from the North coast of Brazil. An additional 30 species were found in the published records from the PRODEMERSAL and PROTUNA, but were considered to be doubtful or pending confirmation.(AU)

Os dados sobre peixes de profundidade encontrados na costa Norte do Brasil são restritos aos resultados de coletas realizadas pelo RV Oregon, um navio do Serviço Nacional de Pesca Marítima da América do Norte, e do Programa REVIZEE. O Programa REVIZEE Score-Norte teve como foco as espécies de peixes com valor comercial e recursos naturais com potencial para exploração na plataforma continental da costa Norte do Brasil. Contudo, o REVIZEE Score-Norte gerou pouca informação sobre as espécies sem valor comercial, não catalogou o material da biodiversidade inventariada, assim como não gerou listas de espécies. Dada a lacuna no conhecimento sobre os peixes de profundidade da costa norte do Brasil, nós compilamos todos os dados disponíveis e recuperamos registros fotográficos do Programa REVIZEE Score-Norte, incluindo os projetos PRODEMERSAL e PROTUNA. Considerando os registros publicados, espécimes depositados em coleções zoológicas e os registros fotográficos, apresentamos uma lista de 63 espécies de peixes de profundidade na costa Norte do Brasil. Outras 30 espécies encontradas nos registros publicados do PRODEMERSAL e PROTUNA, foram consideradas duvidosas, carecendo de confirmação.(AU)

Redescription of Orthopristis ruber and Orthopristis scapularis (Haemulidae: Perciformes), with a hybridization zone off the Atlantic coast of South America.

The genus Orthopristis includes seven valid species, three from the western Atlantic and five from eastern Pacific, while the available identification guides and taxonomic keys incorrectly recognize Orthopristis ruber as the only valid species found on the Atlantic coast of South America. Efforts to expand the inventory of fish species from the northern coast of Brazil led to the identification of two distinct species of Orthopristis from Atlantic South America, based on the analysis of coloration patterns and meristic data, as well as DNA. In the present study, the limits of Orthopristis ruber are reviewed, while Orthopristis scapularis is recognized as a valid species for the northern and northeastern coasts of South America. Based on intermediate morphological characteristics and nuclear DNA markers, a hybrid zone was identified off the state of Espírito Santo, on the eastern Brazilian coast. Additionally, considerations are made on the diversity and biogeography of the coastal marine and estuarine fishes found on the Brazilian coast.

Systematics, biogeography and conservation of Paragenidens grandoculis n. gen. and n. comb. (Siluriformes; Ariidae), a critically endangered species from southeastern Brazil.

Paragenidens, a new genus of ariid catfishes is proposed to accommodate Arius grandoculis, a species previously assigned to the genus Potamarius. Paragenidens grandoculis is an endemic ariid catfish categorized as Critically Endangered and probably Extinct from coastal lacustrine systems from Espírito Santo and Rio de Janeiro states, southeastern Brazil. After more than 50 years without records of the species, new recent fieldwork revealed that the species is extinct at lagoa Juparanã, but still can be found at lagoa Nova in Linhares municipality, Espírito Santo state. Here, Paragenidens is described based on morphological and molecular evidence. In addition to its generic reassignment, the species is redescribed, and comments on its phylogenetic relationships, biogeography and conservation are presented.

Morphology and molecular evidence support the validity of Pogonias courbina (Lacepède, 1803) (Teleostei: Sciaenidae), with a redescription and neotype designation.

The family Sciaenidae comprises about 300 species. The black drum Pogonias cromis was the only valid species of the genus. Herein, Pogonias courbina Lacepède 1803 is redescribed based on morphological and molecular evidence and a neotype is designated. Pogonias courbina is distinguished by the following characters: the occurrence of characteristic thickening of the dorsal spines VII to XI in all specimens larger than 250 mm SL; all pterygiophores in the dorsal-fin laminar, thin; anal-fin pterygiophores slender excluded those of spines; lateral projections of gas bladder with few finger-like projections; genetic distance between both species 1%; exclusive occurrence of characters in six informative sites of COI (58 G; 214 G; 328 A; 331 A; 553C; 580 G). The method Automatic Barcode gap Discovery detected gaps in nucleotid distance congruent with the NJ, MP, and ML tree analysis. Also, advertisement calls are three times shorter in duration in P. courbina than in P. cromis. In addition, two monophyletic groups for P. cromis and P. courbina appear in trees obtained with different methodologies, emphasizing the absence of shared haplotypes. A gap of about 8000 km occurs in the distribution of both species along coastal areas of the Atlantic Ocean.

Record of the rare Caribbean mud eel, Pythonichthys sanguineus (Heterenchelyidae, Anguilliformes), in the region of the Amazon Reef / Registro da rara enguia de lama do Caribe, Pythonichthys sanguineus (Heterenchelyidae, Anguilliformes) na região dos Recifes da Amazônia

As they spend most of their time buried in the substrate and are not a fishery resource, heterenchelyids are seldom seen. These eels are characterized by their greatly reduced eyes, which are covered by semi-transparent skin, the absence of a pectoral fin or lateral line, and no pores on the head or body. Pythonichthys sanguineus is a particularly poorly-known species, with only eight scientific records from Cuba, Puerto Rico, Colombia, Venezuela, Guyana, and Suriname. The present study is based on six adult specimens of P. sanguineus captured by vessels of the shrimp trawling fleet along the northern Brazilian coast, in the vicinity of the Amazon Reef. We provide meristic, morphometric and DNA barcoding data. These findings provide insights into the distribution of the species off the northern Brazilian coast and contribute to the discussion about the southern limit of the Greater Caribbean fauna. (AU)

Heterenchelídeos passam a maior parte do tempo enterrados no substrato e raramente são vistos, não representando recursos pesqueiros importantes. Essas enguias são caracterizadas por seus olhos muito reduzidos e cobertos por pele semi-transparente, ausência de nadadeiras peitorais ou linha lateral, e ausência de poros na cabeça ou no corpo. Pythonichthys sanguineus é uma espécie particularmente pouco conhecida, com apenas oito registros em coleção zoológica para Cuba, Porto Rico, Colômbia, Venezuela, Guiana e Suriname. O presente estudo é baseado em seis espécimes adultos de P. sanguineus capturados pela frota industrial de arrasto de camarão-rosa na costa norte do Brasil, ao largo dos Recifes da Amazônia. Apresentamos dados merísticos, morfométricos e de DNA barcoding dos exemplares examinados. O registro fornece informações importantes sobre a distribuição da espécie na costa norte do Brasil, e contribui para a discussão sobre o limite sul da fauna do Grande Caribe.(AU)

Chinchaysuyoa, a new genus of the fish family Ariidae (Siluriformes), with a redescription of Chinchaysuyoa labiata from Ecuador and a new species description from Peru.

In recent years, morphological and molecular studies have improved our understanding about the relationships and classification schemes of the marine catfishes of the family Ariidae. A taxonomic issue that is still contentious concerns the limits and status of the freshwater Neotropical ariid diversity, in particular the species in the genus Potamarius. The delimitation of Potamarius is currently uncertain given the disjunct distribution of the species in Mesoamerica (Potamarius izabalensis, P. nelsoni and P. usumacintae, from Lake Izabal and Usumacinta River basins in Mexico to Guatemala) and Brazil (P. grandoculis, from coastal lakes in southeastern Brazil). The freshwater Arius labiatus and Hexanematichthys henni from the Peripa and Daule rivers in Ecuador that drain to the Eastern Pacific (EP), have also at times been listed as species inquirenda in Potamarius. Here, we redescribe Arius labiatus, redefine the taxonomic status of Hexanematichthys henni, as junior synonym of Arius labiatus, and describe a new species from Peru that is closely related to Arius labiatus. Based on morphological and molecular phylogenetic evidence, we also describe a new genus (Chinchaysuyoa) for the two South American species.

Revision of Bairdiella (Sciaenidae: Perciformes) from the western South Atlantic, with insights into its diversity and biogeography

The sciaenid genus Bairdiella comprises a group of relatively small fishes found in inshore waters and estuaries of the western Atlantic and eastern Pacific. Despite recent analyses of the phylogenetic relationships of Bairdiella, there has been no comprehensive revision of the alpha taxonomy of the species of the genus. Bairdiella ronchus from the western Atlantic, has a complex taxonomic history, with four junior synonyms recognized. Based on morphological and molecular evidence, this study indicates that B. ronchus represents a species complex. The species is therefore redescribed and its geographic range is redefined. Bairdiella veraecrucis, which is currently recognized as a junior synonym of B. ronchus, is revalidated, and a new species of the genus is described from the Atlantic coast of Brazil. Finally, inferences are made on the diversity and biogeography of the B. ronchus species complex.(AU)

O gênero Bairdiella compreende um grupo de peixes relativamente pequenos encontrados em águas costeiras e estuários do Atlântico ocidental e leste do Pacífico. Apesar das análises recentes das relações filogenéticas de Bairdiella, não houve revisão abrangente da taxonomia alfa das espécies do gênero. Bairdiella ronchus, do Atlântico ocidental, tem uma história taxonômica complexa, com quatro sinônimos juniores reconhecidos. Baseado em evidências morfológicas e moleculares, este estudo indica que B. ronchus representa um complexo de espécies. A espécie é, portanto, redescrita e seu alcance geográfico é redefinido. Bairdiella veraecrucis, atualmente reconhecida como sinônimo júnior de B. ronchus, é revalidada, e uma nova espécie do gênero é descrita na costa atlântica do Brasil. Finalmente, inferências são feitas sobre a diversidade e biogeografia do complexo de espécies de B. ronchus.(AU)

The bony fishes (Teleostei) caught by industrial trawlers off the Brazilian North coast, with insights into its conservation

The Brazilian North coast is one of the world's most important shrimp fishery grounds, with a total area of approximately 223,000 km2. However, the available data on the diversity of fish caught by the region's industrial trawler fleet are limited to the commercially-valuable species. This lacuna in the data on the region's marine fish fauna is worrying, both for the management of stocks and the conservation of the local biodiversity. The present study was based on a comprehensive inventory of the teleost fishes captured by the industrial outrigger trawling operations off the North coast of Brazil. This inventory recorded 201 species belonging to 64 families and 20 orders, and revealed a unique fauna, characterized by 17 endemic species, and a mixture of estuarine-dependent and marine species, mainly associated with coral reefs. The Kernel density analysis indicated that the industrial trawling fleet operates within an important ecotone, which encompasses the transition zones of different fish communities found off the Brazilian North coast.(AU)

A costa Norte do Brasil é um dos pesqueiros de camarão mais importantes do mundo, com uma área total de aproximadamente 223.000 km2. No entanto, dados disponíveis sobre a diversidade de peixes capturados pela frota industrial de arrasto de portas na região são limitados às espécies com valor comercial. Essa lacuna no conhecimento sobre a fauna de peixes marinhos da região é preocupante, tanto para o manejo dos estoques quanto para a conservação da biodiversidade local. O presente estudo é baseado num inventário abrangente dos peixes teleósteos capturados por operações de arrasto de portas da frota industrial que opera na costa Norte do Brasil. Este inventário registrou 201 espécies pertencentes a 64 famílias e 20 ordens, e revelou uma fauna única, caracterizada por 17 espécies endêmicas, e uma mistura de espécies estuarino-dependentes e espécies marinhas, principalmente associadas a recifes de corais. A análise da densidade Kernel indicou que a frota industrial de arrasto de portas opera dentro de um importante ecótono, que abrange uma zona de transição de diferentes comunidades de peixes encontrados na costa Norte do Brasil.(AU)

Conhecimento e conservacao dos peixes marinhos e estuarinos (Chondrichthyes e Teleostei) da costa norte do Brasil

The tropical western South Atlantic, which includes a substantial portion of the Brazilian Exclusive Economic Zone, is a region of endemism broadly recognized as being of prime importance for the conservation of the marine biodiversity. The north coast of Brazil, which comprises the states of Amapá, Pará and Maranhão from the mouth of the rio Oiapoque to the mouth of the rio Parnaíba, harbors the largest continuous mangrove in the world, with approximately 8,900 km2. The high discharge of freshwater and continental sediments in the delta of the Amazonas affects the regime of tides, ocean currents, and several oceanographic processes of the north coast, with direct impact on the composition of the biota found in the region. Despite its economic value and intrinsic biological relevance, several aspects of the diversity of the marine and estuarine fishes of the region are poorly known. This situation results mainly from a historical imbalance in terms of the number of studies devoted to increasing the knowledge of the marine biota along the Brazilian coast, such as those dealing with species inventory and taxonomic revisions, which are typically concentrated in the south and southwestern portions of the country. The scientific production focused on marine organisms of the north coast is also imbalanced, and reflects the relatively small number of taxonomists and research groups working on that subject. The insufficient knowledge of the biodiversity of the marine and estuarine fishes of the north coast is an impediment to the implementation of adequate public policies aimed at the management of natural resources in the region. In the long term, that situation is potentially harmful in terms of conservation of a still poorly known biota. A better understanding of the marine fish fauna of the north coast of Brazil will be achieved only through the investment in scientific research and personnel training in systematics and biogeography, coupled with the modernization of the current infrastructure and expansion of scientific collections of the region.

A região tropical do Atlântico Sul ocidental, que inclui uma porção substancial da Zona Econômica Exclusiva brasileira, é uma região de endemismo amplamente reconhecida como sendo de importância primária para a conservação da biodiversidade marinha. A costa norte do Brasil, que inclui os Estados do Amapá, Pará, e Maranhão, desde a foz do rio Oiapoque até a foz do rio Parnaíba, abriga o maior manguezal contínuo do mundo, com aproximadamente 8.900 km2. A alta descarga de água doce e sedimentos continentais no delta do Amazonas afeta o regime das marés, correntes oceânicas, e uma série de processos oceanográficos da costa norte, com impactos diretos na composição da biota encontrada na região. Apesar de seu valor econômico e relevância biológica intrínseca, diversos aspectos da diversidade de peixes marinhos e estuarinos da região são pouco conhecidos. Esta situação resulta principalmente de um desequilíbrio histórico em termos do número de estudos voltados ao conhecimento da biota marinha ao longo da costa brasileira, como aqueles que tratam do inventariamento de espécies e revisões taxonômicas, que são tipicamente concentrados nas porções sul e sudeste do país. A produção científica focalizada nos organismos marinhos da costa norte também é desequilibrada e reflete o número relativamente baixo de taxonomistas e grupos de pesquisa trabalhando com o tema. O conhecimento insuficiente da biodiversidade dos peixes marinhos e estuarinos da costa norte é um impedimento à implantação de políticas públicas adequadas voltadas para o manejo dos recursos naturais na região. À longo prazo, essa situação é potencialmente prejudicial em termos da conservação de uma biota ainda pouco conhecida. Um melhor conhecimento da fauna de peixes marinhos da costa norte do Brasil será atingido apenas através do investimento em pesquisas científicas e formação de pessoal em sistemática e biogeografia, acoplado à modernização da infra-estrutura e expansão das coleções científicas da região.

A ictiofauna do Canal de Bertioga, São Paulo, Brasil / The ichthyofauna of the Bertioga Channel, São Paulo, Brazil

O Canal de Bertioga, localizado no litoral do estado de São Paulo, é delimitado pelo continente e pela ilha de Santo Amaro, constituindo a unidade natural que conecta os municípios de Santos, Guarujá e Bertioga, representando uma segunda conexão do complexo estuarino de Santos-São Vicente com o oceano. No presente estudo foram realizadas coletas, entre dezembro de 2009 a novembro de 2010, no trecho norte do Canal de Bertioga (23° 51' 23,83" S e 46° 07' 58,87" O e 23° 53' 31,72" S e 46° 11' 17,74" O), com o objetivo de inventariar a ictiofauna da região. Foram coletados 1.429 exemplares, pertencentes a 78 espécies, incluídas em 14 ordens, 39 famílias e 67 gêneros. As famílias mais especiosas foram Sciaenidae (nove spp.), Carangidae (nove spp.), Haemulidae (sete spp.), e Ariidae (cinco spp.), e as espécies mais abundantes foram Stellifer rastrifer (n = 243), Harengula clupeola (n = 182), Cathorops spixii (n = 144), Oligoplites palometa (n = 109) e Mugil curema (n = 102), sendo que Achirus lineatus, Atherinella brasiliensis, Cathorops spixii, Chaetodipterus faber, Citharichthys spilopterus, Genidens genidens, Micropogonias furnieri e Stellifer rastrifer, ocorreram em todas estações do ano. Das espécies encontradas, seis foram reconhecidas constantes, 19 acessórias e 53 ocasionais. Em relação aos seus hábitos, 40 espécies são marinho-estuarinas, 26 marinhas, 11 estuarinas e uma de água doce, sendo 52 espécies demersais e 26 pelágicas. Onze espécies são relacionadas em listas de espécies ameaçadas. Adicionalmente, é apresentada uma chave de identificação para as espécies do trecho norte do Canal de Bertioga.

The Bertioga Channel, on the coast of the São Paulo state, is delimited by the continental shore and the island of Santo Amaro, and represents a secondary connection of the Santos-São Vicente estuarine complex to the ocean and adjoins the municipalities of Santos, Guarujá and Bertioga. In the present study collections were made between December 2009 and November 2010 in the northern stretch of the Bertioga Channel (23° 51' 23,83" S, 46° 07' 58, 87" W to 23° 53' 31,72" S, 46° 11' 17,74" W) in order to provide an inventory of the ichthyofauna of the region. A total of 1,429 specimens were collected, belonging to 78 species, 67 genera, 39 families and 14 orders. The most species rich families were Sciaenidae (nine spp.), Carangidae (nine spp.), Haemulidae (seven spp.), and Ariidae (five spp.). The most abundant species were Stellifer rastrifer (n = 243), Harengula clupeola (n = 182), Cathorops spixii (n = 144), Oligoplites palometa (n = 109) and Mugil curema (n=102). The species Achirus lineatus, Atherinella brasiliensis, Cathorops spixii, Chaetodipterus faber, Citharichthys spilopterus, Genidens genidens, Micropogonias furnieri and Stellifer rastrifer, were collected in all seasons of the year. Of the species encountered, six were considered constant, 19 accessorial and 53 occasional. In relation to habitat association, 40 species are marine-estuarine, 26 species marine, 11 species estuarine and one species freshwater, being 52 demersal species and 26 pelagic species. Eleven species are included in red lists. Additionally, an identification key to the species of the northern stretch of the Bertioga Channel is presented.

A ictiofauna de cabeceiras do rio Tietê, São Paulo, Brasil / The ichthyofauna from the headwaters of the rio Tietê, São Paulo, Brazil

Uma síntese das espécies de peixes de cabeceiras do rio Tietê é apresentada com base em material de coleções zoológicas e novas coletas realizadas. São referidas para região 56 espécies pertencentes a sete ordens e 16 famílias, aumentando significativamente números anteriores. Os resultados mostram que as cabeceiras do rio Tietê possuem uma composição ictiofaunistica bastante peculiar, distinta daquela encontrada no restante do Alto rio Paraná, mostrando acentuado grau de endemismo e grande similaridade com bacias hidrográficas litorâneas, corroborando a hipótese de captura de rios da região por drenagens costeiras e vice e versa no passado. Dentre as espécies encontradas na região, oito são endêmicas (14,3 por cento), 13 são encontradas nas cabeceiras do rio Tietê e drenagens litorâneas da região sudeste do Brasil (23,2 por cento), dez ocorrem em todo Alto rio Paraná (17,9 por cento), cinco são encontradas no Alto rio Paraná e drenagens litorâneas da região sudeste do Brasil (8,9 por cento), enquanto 13 espécies mostram uma ampla distribuição na América do Sul (23,2 por cento), das quais parte ainda precisa ter a identidade confirmada. A diversidade de espécies é acrescida de pelo menos cinco espécies novas pertencentes aos gêneros Cyphocharax, Characidium, Astyanax, Pareiorhina e Australoheros e quatro novos registros são feitos para Characidium cf. zebra, Scleromystax barbatus, Crenicicla britskii e Synbranchus cf. marmoratus. Pelo menos sete espécies introduzidas estão estabelecidas na região, enquanto outras dez espécies são relacionadas em listas de espécies ameaçadas.

A synthesis of the ichthyofauna of the headwaters of the rio Tietê, based on material from zoological collections and new samplings, is presented. Fifty six species belonging to seven orders and 16 families are recorded to the drainage, increasing previous numbers significantly. The current results show that the headwaters of the rio Tietê possess a singular ichthyofauna composition, diverse from that found in the remaining of the upper Paraná basin, with high level of endemic species and great similarity to the species from coastal drainages. This finding corroborates the hypothesis of past river capture between streams and rivers in both drainages. Among the species occurring in the area surveyed, eight are endemic (14.3 percent), 13 are found in the headwaters of rio Tietê and in the coastal drainages of southeastern Brazil (23.2 percent), 10 are present throughout the upper Paraná basin (17.9 percent), five are found in the upper Paraná basin and in the coastal drainages of southeastern Brazil (8.9 percent), while 13 show a broader distribution in the South America drainages (23.2 percent), part of which still remains to be identified. Species diversity increased with the discovery of at least five new species belonging to the genera Cyphocharax, Characidium, Astyanax, Pareiorhina and Australoheros, and four new records for Characidium cf. zebra, Scleromystax barbatus, Crenicicla britskii and Synbranchus cf. marmoratus. At least, seven non-native species are recognized to be established in the region, while 10 other are included in red books.