The Parnaíba River is the largest hydrographic basin with its limits entirely within the northeastern region of Brazil. It is one of the few perennial rivers in the Brazilian Northeastern Region, running predominantly in the area of Caatinga on the eastern portion (with intermittent drainages associated to this type of environment), and partly extending into the Cerrado region on the western portion. The objective of this study was to describe the diversity of freshwater fishes of the Parnaíba River basin by conducting a comprehensive ichthyofauna inventory of the basin. The sampling design of this study was based on the placement of (1) Fixed Sites for seasonal collection (dry and wet season, two years) in the three portions of the main course of the Parnaíba River, and (2) ''Aquarap'' protocol collections which covered the entire basin. The collection effort consisted of 244 sampling sites surveyed along the entire basin between the years 2004 and 2011. Fish were collected with the use of seines, cast nets, gill nets and dip nets; only the first two fishing gears were used in Fixed Sites. As a result, 146 species of freshwater fish were recorded in the Parnaíba River basin, distributed in 103 genera, 36 families and 11 orders. The registered endemism reached a total of 54 species.

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may represent areas of reproduction, protection and feeding for some marine species, including commercially important. The east coast of Rio Grande do Norte is composed by small and medium-sized basins partially or fully inserted in the Atlantic Forest, representing the northern extreme of this biome, with only 4.1% of the native vegetation (Fundação SOS Mata Atlântica and INPE 2012), composed by small isolated fragments. Therefore, the aim of this study was to inventory the ichthyofauna of the coastal Pratagi River basin, located on the east coast of the state, region with intense tourist activities, and report the main anthropogenic impacts on the basin, to increase the knowledge and support to conservation strategies for the Atlantic Forest fish fauna. Material and Methods Study site The study was conducted in Pratagi River basin, located in Ceará-Mirim Municipality, Rio Grande do Norte State. The main course of the Pratagi River has about 10 km long and is a tourist natural attraction of Rio Grande do Norte coast due to its high landscape value, with two popular sites mainly visited by tourists who make buggy rides in dune areas at the east coast, the Lavacu and Cachoeirinha Pitangui waterfall. The Pratagi River mouth is distant about 30 km from Natal, state capital city, and the main river course presents excerpts with clear waters fringed by dunes in Restinga and Atlantic Forest remnants until emptying into the Atlantic Ocean (Figure 1). Data collection Eleven samples were taken from five sites along Pratagi River basin, from the headwaters to the estuarine portion.

In most ecological field research, appropriate sampling is critical for the understanding of processes underlying fish populations and communities, and is even more important in heterogeneous environments such as the aquatic systems of the semi-arid region of Brazil. This study intends to make a contribution to the development of sampling programs and gear selection in aquatic systems of semi-arid Brazil by evaluating the effects of different fishing techniques on the assessment of richness and composition of the fish fauna in selected aquatic environments. Six sites were selected to represent typical artificial (reservoirs) and natural (intermittent streams) environments and four different types of sampling gear were applied to each site during four occasions. The present study shows that when selecting sampling techniques to be used in aquatic systems in semi-arid Brazil, one must consider the objectives of the study, e.g. ecological or taxonomic, in order to decide on inclusion of rare species in the sampling population. Also, the effect of the sampling gear on natural abundances of fish must be considered given that some sampling techniques are highly detrimental to fish population numbers.Keywords: semi-arid, fish, richness, sampling technique, intermittent streams. Efeitos de diferentes artes de pesca na avaliação da composição de espécies em ambientes aquáticos do semiárido brasileiro ResumoNa maioria dos estudos ecológicos, uma amostragem representativa é crucial para o conhecimento dos processos que organizam populações e comunidades de peixes, principalmente em ambientes reconhecidamente heterogêneos como os ecossistemas aquáticos da região semiárida do Brasil. O presente estudo pretende contribuir para este conhecimento avaliando os efeitos de diferentes técnicas de captura de peixes na riqueza e composição das espécies amostradas em ambientes aquáticos do semiárido. Seis pontos de coleta foram selecionados, representando ambientes aquáticos artificiais (açudes) e naturais (rios intermitentes), onde quatro tipos de apetrechos de pesca foram empregados em quatro ocasiões. O presente estudo mostra que, ao selecionar técnicas de amostragem de peixes em ambientes aquáticos do semiárido brasileiro, dois fatores devem ser levados em consideração: primeiro, os objetivos do estudo, ecológicos ou taxonômicos, para se avaliar a importância da inclusão de espécies raras na população amostral; e segundo, os efeitos da técnica de amostragem na abundância natural de espécies, tendo em vista que algumas artes de pesca têm um efeito negativo nos números populacionais das espécies de peixes.Palavras-chave: semiárido, peixes, riqueza de espécies, artes de pesca, rios intermitentes.

This study records the first occurrence of Kryptolebias hermaphroditus Costa, 2011 in canals or perennial salty water pools in two mangroves of the Rio Grande do Norte state, in the estuaries of Ceará-Mirim River and Curimataú River. Due to its hermaphroditism and self-fertilization, a unique feature among vertebrates, this species is very important for many biological areas. Kryptolebias hermaphroditus depends on favorable conditions for their development, therefore, human impacts such as shrimp farming and removal of native vegetation from mangroves may affect populations of this species in northeastern Brazil.

Humid highland forest enclaves are remnants of Atlantic Forest found in tablelands within the Caatinga biome (Northeastern Brazil), which emerged during interglacial periods in the Pleistocene. These ecosystems have a highly diverse and endemic fish fauna. Most earlier surveys have focused on the tableland of Borborema (Pernambuco and Paraíba States). In this study we surveyed the fish fauna of the humid forest enclaves in the tablelands of Ibiapaba and Araripe, based on samples collected in the rainy season (March and April) between 2009 and 2014. The 45 sampling points covered rivers, streams and reservoirs in five river basins belonging to three ecoregions. The species were listed according to drainage divide, and endemism was determined for each ecoregion and for the Caatinga. Our area was more species-rich (n=59) than Borborema (n=27). The samples included five introduced species and 29 species endemic to the Caatinga (49.1% of the sampled species). The distribution of Parotocinclus haroldoi was expanded to the Mid-Northeastern Caatinga ecoregion (Timonha river basin, Ceará State). Our study intends to make a significant contribution to current knowledge of the ichthyofauna in humid highland forest enclaves of semiarid Northeastern Brazil, identified as a priority in the conservation of the biodiversity in the Caatinga.

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.

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. Keywords: Endemism, Paraíba, Basins Transposition. Composição da ictiofauna em reservatórios do semiárido brasileiroResumo: 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 red...