Abstract Mixed stocks are described for Chelonia mydas and the frequency of haplotypes in feeding areas can aid understanding of the genetic and ecological diversity, since with this information it is possible to identify the origin of the individuals. The current study aims to characterize and compare genetic diversity along the coast of Paraná with 17 other feeding areas in the Atlantic Ocean. A total of 285 samples from juveniles were DNA sequenced in the control region, resulting in the identification of 12 haplotypes, with a predominance of the CMA8 haplotype (69%) and the first registration of CMA23. For the study subjects, haplotypic and nucleotide diversity were 0.469 ± 0.032 and 0.00189 ± 0.00020, respectively, and comparisons with other feeding areas presented significant values for the majority of FST and ΦST. The results point to the importance of this region and provide evidence that over the years a mixed stock has used the region as a feeding area. This variation could be related to sea currents, climatic changes, and oceanographic characteristics that may alter the availability of food, water temperature, and the presence of turtles. The current results can be considered in conservation plans for Chelonia mydas.

Abstract Fish eggs are often excluded from identification analysis since at this stage of development there are few morphological characters. The correct identification of eggs can provide important information about spawning areas of species. The current work aimed to identify fish eggs in the Tibagi and Cinzas Rivers using the DNA barcode to obtain information on richness and diversity, adding to the existing data in the area. Of the 928 sequences analyzed using the BOLD Systems database, 99.78% were able to be identified at a specific level, demonstrating a high success rate for egg identification. The samples resulted in 25 species, 11 families, and 2 orders. Of the 25 species found, more than half (60%) present reproductive migration behavior, indicating that the tributaries of the Capivara reservoir are being used as a migratory route by these species. Eggs of rare and endangered species were found, indicating these tributaries as spawning grounds for these species. The results demonstrate the importance of identifying fish eggs in reservoir-influenced environments to recognize breeding areas of native and endangered species, as well as the importance of the Tibagi and Cinzas Rivers for the maintenance of native fish species in the Paranapanema River.

Resumo: O rio Paranapanema é um importante tributário, amplamente explorado da bacia do Alto rio Paraná. A fauna de peixes do rio Paranapanema vem sendo investigada desde a década de 1990; no entanto, nenhum estudo caracterizou a riqueza de espécies de peixes em toda a bacia, incluindo o canal principal do rio, lagoas marginais, seus tributários e sub-tributários. Assim, realizamos uma revisão com 90 estudos independentes conduzidos nas regiões superior, média e inferior da bacia. Foram registradas 225 espécies, das quais 165 eram nativas e 60 eram não nativas. Verificamos que 77% das espécies dentro da bacia são compostas por Siluriformes e Characiformes. Cichliformes apresentou um número significativo de espécies não nativas estabelecidas em áreas de represamento da bacia. Estimadores de riqueza baseados em incidência (Bootstrap e Chao 2) demonstraram que a riqueza de espécies nativas ainda é subestimada. Algumas espécies nativas (e.g., Hypostomus ancistroides) e não nativas (e.g., Plagioscion squamosissimus) estão amplamente distribuídas na bacia, enquanto outras tem sua distribuição mais restrita. Entre as espécies registradas, a família Bryconidae obteve o maior número de representantes com status de conservação ameaçado. Além disso, observamos que o reservatório de Capivara e seus afluentes foram as regiões mais amostradas, sendo a maioria dos estudos realizados na bacia do baixo Paranapanema. A riqueza de espécies registrada em grandes afluentes, como os rios Tibagi, Cinzas, Congonhas e Pirapó, é fundamental para a manutenção da ictiofauna no rio Paranapanema. Nossa contribuição pode ser usada para apoiar ações de manejo e estratégias de conservação, bem como para indicar regiões na bacia que precisam ser melhor inventariadas.

Abstract: The Paranapanema River is an important, extensively explored tributary of the Upper Paraná River basin. The fish fauna of the Paranapanema River has been investigated since the 1990s; however, no study has characterized the richness of fish species throughout the basin, including the main channel of the river, marginal lagoons, its tributaries, and sub-tributaries. Thus, we performed a review with 90 independent studies conducted at the upper, middle, and lower sections of the basin. We recorded 225 species, of which 165 were native, and 60 were non-native. We found that 77% of the species within the basin are composed by Siluriformes and Characiformes. Cichliformes had a significant number of non-native species established in impoundment sections of the basin. Incidence-Based Estimators (Bootstrap and Chao 2) demonstrated that the richness of native species is still underestimated. Some native (e.g., Hypostomus ancistroides) and non-native species (e.g., Plagioscion squamosissimus) are widely distributed in the basin, while others had a more restricted distribution. Among the registered species, the family Bryconidae had the highest number of representatives with threatened conservation status. In addition, we observed that the Capivara Reservoir and its tributaries were the most sampled regions, with the majority of studies performed in the Lower Paranapanema basin. The species richness recorded in large tributaries, such as Tibagi, Cinzas, Congonhas, and Pirapó rivers is critical for maintaining the fish fauna in the Paranapanema River. Our contribution may be used to support management actions and conservation strategies, as well as to indicate regions in the basin that need to be better inventoried.

Resumen Los riesgos de pérdida de diversidad de peces aumentan con la construcción de represas, ya que impide la dispersión de individuos entre las poblaciones. Por lo tanto, la conservación del habitat ribereño clave para la reproducción de peces puede ser esencial para el reclutamiento de nuevos individuos de especies nativas. El presente estudio tiene como objetivo identificar hábitats clave para el desove y el desarrollo temprano de peces en la cuenca del río Paranapanema, así como determinar la composición taxonómica, la estrategia reproductiva y la historia de vida, y reportar la distribución espacial de huevos, larvas y juveniles. Se evaluó la importancia de lagunas, afluentes y subafluentes en la cuenca del río Paranapanema entre octubre de 2012 y marzo de 2013. Se recogieron muestras de huevos y larvas al amanecer y al atardecer con redes de plancton cónico (tamaño de malla de 0,5 mm), mientras que los juveniles fueron capturados durante el día con redes de cerco y tamiz (tamaño de malla de 0,5 cm). Se capturaron un total de 547 huevos, 904 larvas y 1 228 juveniles. Como resultado fue observado que 2 larvas y 288 juveniles de especies no migratorias, cuidado parental y estrategia de vida de equilibrio son predominantes en lagunas y afluentes. Por otro lado, 13 larvas y 60 juveniles de espécies migratorias de corta distancia, sin cuidado parental y estrategia de vida periódica predominaron en subafluentes. Se registraron las densidades más altas de huevos para afluentes y subafluentes (Prueba de Tukey, P = 0.001 y P = 0.03, respectivamente), y se registraron las densidades más altas de larvas para las lagunas y afluentes (P = 0.005 y P = 0.0001, respectivamente). Las capturas de huevos y larvas eran más altas por la noche. Las mayores capturas por unidad de esfuerzo de juveniles se registraron para los afluentes y subafluentes. Las especies de peces que adoptan diferentes estrategias de historia de vida pueden utilizar diversos tipos de hábitats durante las primeras etapas. Lagunas, afluentes y subafluentes del río Paranapanema desempeñan diferentes papeles en el éxito reproductivo de la fauna de peces en una cuenca fuertemente modificada. La preservación de áreas de desove y cría atrapadas entre el embalse es necesaria para el reclutamiento de especies de peces neotropicales.

Abstract Fish diversity loss is threatened by the construction of dams as they prevent the regular natural dispersal among populations. Thus, conservation of key riverine habitats for fish reproduction may be essential for the recruitment of new native species of fish. The present study aimed to identify key habitats for fish spawning and early development in the Paranapanema River basin, as well as to determine the taxonomic composition, reproductive and life-history strategy, and to report spatial distribution of eggs, larvae and juveniles. The importance of lagoons, tributaries, and sub-tributaries was evaluated in the Paranapanema River basin between October 2012 and March 2013. Eggs and larvae samples were collected at dawn and dusk with conical plankton nets (0.5 mm mesh size), whereas juveniles were captured during the day with seine and sieve (0.5 cm mesh size). A total of 547 eggs, 904 larvae and 1 228 juveniles were captured. We observed that 2 larvae and 288 juveniles of non-migratory species, parental care, and equilibrium life-history strategy, predominated in lagoons and tributaries. On the other hand, 13 larvae and 60 juveniles of short migratory distance, no parental care, and periodic life-history strategy predominated in sub-tributaries. The highest densities of eggs were recorded in tributaries and sub-tributaries (Tukey’s test, P = 0.001 and P = 0.03, respectively), and the highest densities of larvae were recorded for lagoons and tributaries (P = 0.005 and P = 0.0001, respectively). Captures of eggs and larvae were higher at night; while the highest catches per unit effort of juveniles were recorded for tributaries and sub-tributaries. Fish species that adopt different life-history strategies can use diverse types of habitats during the early stages. Lagoons, tributaries and sub-tributaries of the Paranapanema River play different roles in the reproductive success of fish fauna in a heavily modified basin. The preservation of spawning and nursery areas trapped between reservoirs is necessary for Neotropical fish species recruitment and survival. Rev. Biol. Trop. 66(2): 605-621. Epub 2018 June 01.

ABSTRACT Non-native species are a major driver of biodiversity loss. Aquaculture activities play a key role in introductions, including the escape of fishes from fish farm facilities. Here, the impact of flooding due to El Niño rains in 2015/2016 in the Lower and Middle Paranapanema River basin, southern Brazil, was investigated by evaluating fish escapes from 12 fish farms. The flooding resulted in the escape of approximately 1.14 million fishes into the river, encompassing 21 species and three hybrids. Non-native species were the most abundant escapees, especially Oreochromis niloticus (Linnaeus, 1758) and Coptodon rendalli (Boulenger, 1897) (96% of all fish). Only seven native fishes were in the escapee fauna, comprising 1% of all fish. Large floods, coupled with inadequate biosecurity, thus resulted in considerable inputs of non-native fish into this already invaded system.

Treze loci microssatélites foram isolados e caracterizados em Microglanis cottoides. Destes, dois foram monomórficos e 11 foram polimórficos. Estes loci polimórficos foram testados em 24 indivíduos de uma população selvagem e produziram um total de 108 alelos diferentes, com níveis de variabilidade alta, variando de 2 a 20, com uma média de 8,3 alelos por locus. A heterozigosidade observada e esperada variou de 0,125 a 0,958 e 0,119 a 0,931, respectivamente. Um elevado valor de exclusão de paternidade e um baixo valor de identidade genética foram obtidos, demostrando que o conjunto de loci descritos no presente trabalho exibe boa aplicabilidade no estudo de parentesco e diferenciação populacional em M. cottoides. Adicionalmente, os treze primers de microssatélites desenvolvidos para M. cottoides foram testados em outras quatro espécies de Pseudopimelodidae e a transferabilidade foi obtida para a maioria dos loci.

Thirteen microsatellite loci were isolated and characterized in Microglanis cottoides. Of these, two were monomorphic and 11 were polymorphic. These polymorphic loci tested on 24 individuals from a wild population produced a total of 108 different alleles, with levels of variability high, ranging from 2 to 20, with an average of 8.3 alleles per locus. The observed and expected heterozygosity ranged from 0.125 to 0.958 and from 0.119 to 0.931, respectively. A high combined probability of paternity exclusion value and a low probability combined genetic identity value obtained show that the set of loci described herein displays good suitability for paternity studies and differentiation of M. cottoides. Additionally, all thirteen microsatellite primers developed for M. cottoides were tested in four other Pseudopimelodidae species and successful cross-species amplification was achieved for the majority of loci.

Conservar a variabilidade genética dos estoques de alevinos de peixes para suplementar populações naturais é uma prioridade. O objetivo deste estudo foi examinar a diversidade genética por meio dos marcadores de RAPD de amostras de peixes reprodutores de dourado do médio Paranapanema (população natural) e alevinos usados no programa de repovoamento da estação de aquicultura da UHE de Salto Grande. Foram analisados 19 primers de RAPD, que geraram 299 bandas, as quais foram utilizadas para as análises genéticas. A porcentagem de fragmentos polimórficos foi mais elevada na população natural do que nos estoques. A diversidade genética também foi mais baixa nos alevinos. Os resultados da Amova mostraram que a maior parte de variação genética interpopulacional está dentro dos estoques (83,9%) e não entre eles (16,1%). Foi observada uma diferenciação genética moderada (F ST = 0.16). Esta diferenciação diminuiu quando os quatro estoques de alevinos eram misturados e analisados como uma única população (F ST = 0.07). Em vez de liberar cada lote separadamente no ambiente, seria melhor misturar todos os indivíduos produzidos nos vários estoques de alevinos antes de liberá-los no rio. Desta maneira, a população reintroduzida terá uma estrutura genética mais perto da população natural.

The preservation of the genetic variability of hatchery stocks used to supplement natural populations is a priority. Current study employed RAPD markers to examine the genetic diversity of dourado samples from the middle Paranapanema river and from the broodstock used in the stock enhancement program of the Aquaculture and Hydrobiology Station at the Salto Grande Hydroelectric Power Plant. Nineteen RAPD primers were analyzed, which generated 299 bands and the latter were used for genetic analysis. The percentage of polymorphic fragments was higher in stock captured in the Paranapanema river than from fry stocks. The genetic diversity was lower in the broodstock than in natural population. Amova results showed that most inter-population genetic variation lay within stocks (83.9%) and not between them (16.1%). Moderate genetic differentiation (F ST = 0.16) was reported. Nevertheless, differentiation decreased when the four fry stocks were mixed and analyzed as a single population (F ST = 0.07). Instead of releasing each lot separately into the water, mixing specimens produced in the various fry stocks before releasing them in the river would be more feasible. The restocked population will have a genetic structure closer to natural populations.

Exemplares de Pimelodella capturados no rio Miranda, Pantanal do Mato Grosso do Sul, apresentavam características morfológicas que poderiam indicar, pelo menos, quatro espécies. Entretanto, com a análise cariotípica e da biologia molecular ficou evidente que se tratava de apenas duas espécies, uma apresentando 2n = 46 e a outra, 2n = 52 cromossomos, e com apenas 18% de similaridade genética. Pela análise morfológica foi observado que o filamento dorsal é uma característica de machos, e o lobo superior da nadadeira caudal se mostrou variável, podendo, ou não, ser alongado em ambas espécies. Com relação aos caracteres morfométricos, também houve a formação de dois grupos, mas com uma pequena sobreposição de exemplares entre eles. Das espécies com filamento na nadadeira dorsal apontadas para o Pantanal, a que possui menor comprimento da base da nadadeira adiposa é P. griffini, o que corresponde àquela com 2n = 46 cromossomos e, ao contrário, a espécie com 2n = 52 cromossomos, é P. taenioptera. Assim, apenas com o emprego de diversas técnicas de análise foi possível o reconhecimento seguro dessas unidades taxonômicas que se mostravam crípticas. Ressalta-se, ainda, que a identificação de espécies crípticas é importante para que estimativas da diversidade de peixes do Pantanal sejam feitas corretamente

Specimens of Pimelodellacaptured in the Miranda River, Pantanal of Mato Grosso do Sul State, present morphological features that could indicate at least four species. Therefore, karyotype analysis and molecular biology provided evidence that they were only two species, one showing 2n = 46, and the other, 2n = 52 chromosomes, with only 18% genetic similarity. The morphological analysis evidenced that the dorsal filament is a male characteristic and that the upper lobe of the caudal fin was variable and might or might not be elongated in both species. With respect to morphometric characters, the formation of two groups was evident, but with a small overlap of specimens between them. Among the species with filaments on the dorsal fin observed in the Pantanal, the one with the lesser length of adipose fin base is P. griffini, which corresponds to that with 2n = 46 chromosomes, whereas the species P. taenioptera has 2n = 52 chromosomes. Thus, the accurate detection of these cryptic taxonomic units was only possible with the use of various analysis techniques. Furthermore, it is worth noting that the identification of cryptic species is important for obtaining correct estimates of fish diversity in the Pantanal

As barragens construídas ao longo de sistemas hídricos interrompem a dispersão e a migração dos organismos aquáticos, afetando principalmente a abundância das espécies de peixes migradores. Mecanismos para transposição foram construídos em barragens visando minimizar esses impactos. Poucas são as informações disponíveis sobre o efeito da construção de barragens na estrutura genética populacional da fauna neotropical de peixes migradores. Nesse contexto, marcadores moleculares RAPD e microssatélites foram utilizados para avaliar a diversidade e a estrutura genética da espécie migradora Leporinus elongatus (piapara) no Complexo Canoas - rio Paranapanema - Brasil. Dez grupos foram amostrados nas escadas para transposição de peixes das UHEs Canoas I e Canoas II durante o período reprodutivo em três anos consecutivos. Ambos os marcadores evidenciaram uma alta diversidade genética para esses grupos. Os marcadores microssatélites mostraram uma perda de heterozigosidade e uma considerável taxa de endocruzamento para a espécie. A diferenciação genética encontrada entre os grupos, com ambos os marcadores utilizados, pode ser considerada de moderada a baixa. Os dados obtidos com os parâmetros de diversidade genética entre os grupos permitiram concluir que os grupos de L. elongatus do Complexo Canoas estão estruturados como uma única população composta por sub-populações com baixa diversidade genética entre elas. Os dados obtidos sobre a diversidade genética e estrutura populacional de L. elongatus são de grande importância para o desenvolvimento de programas de manejo e conservação da espécie no Complexo Canoas, podendo também ser utilizados em programas de aqüicultura.

Dams constructed along waterways interrupt the dispersion and migration of aquatic organisms, affecting mainly the abundance of migratory fish species. Translocation mechanisms have been constructed at dams aiming to minimize their impact on fish species migration behavior. There is little information available about the effect of the construction of dams on the genetic structure of the Neotropical migratory fish fauna. Therefore, RAPD molecular markers and microsatellites were utilized to evaluate the diversity and genetic structure of the migratory species Leporinus elongatus (piapara) in the Canoas Complex - Paranapanema River - Brazil. Ten groups were sampled in the fish ladders of the hydroelectric dam Canoas I and Canoas II during the reproductive period in three consecutive years. Both markers showed a high level of genetic diversity within these groups. The microsatellite markers demonstrated a loss of heterozygosity and a considerable level of inbreeding in the species. The genetic differentiation found among the groups with both markers utilized is within a range from low to moderate. The data obtained with the parameter of genetic diversity among the groups led to the conclusion that the groups of L. elongatus of the Canoas Complex are structured as a single population composed of sub-populations with low genetic diversity among them. The data on genetic diversity and population structure of L. elongatus are of great importance for the development of the species management and conservation programs in the Canoas Complex, which can also be utilized in aquaculture programs.

O objetivo desse estudo, utilizando a técnica de RAPD, foi estimar a variabilidade genética de grupos de Salminus brasiliensis coletados nas escadas de transposição das hidroelétricas de Canoas I e Canoas II - rio Paranapanema (Brasil), bem como estimar a estrutura populacional através de diferentes parâmetros de diversidade genética. Os dados obtidos permitiram concluir que S. brasiliensis do Complexo Canoas tem um índice moderado de variabilidade genética ( > 42.00%) quando comparado com valores de outras espécies de peixes migradoras. Todas as análises de diversidade genética (distância = 0,015 e identidade genética = 0,985, F ST =0,018, AMOVA) foram indicativas de baixa diferenciação genética, e conduziram ao agrupamento de S. brasiliensis proveniente das escadas de transposição de Canoas I e Canoas II, sugerindo que essa espécie está geneticamente estruturada como uma única população. Alguns dados indicam que essa população de S. brasiliensis é proveniente do Reservatório de Capivara (jusante de Canoas I), provavelmente mantida pelos rios Tibagi e das Cinzas. Dados da literatura indicam que após a transposição das escadas para peixes do Complexo Canoas, as espécies migradoras não estão concluindo o ciclo reprodutivo, esse mecanismo, portanto, pode ser mais um fator de impacto causando a depleção no recrutamento a jusante o que pode a médio e longo prazo comprometer a diversidade genética da população de S. brasiliensis no médio rio Paranapanema.

The aim of this study, utilizing RAPD techniques, was to determine the genetic variability of Salminus brasiliensis groups collected at passage ladders of the hydroelectric plants (HEP) Canoas I and Canoas II - Paranapanema River (Brazil), as well as to estimate the population structure through different parameters of genetic diversity. The data obtained allowed us to conclude that S. brasiliensis of the Canoas Complex has a moderate index of genetic variability ( > 42.00%) when compared to that of other migratory fish species. All genetic diversity analyses (distance = 0.015 and genetic identity = 0.985, F ST =0.018, AMOVA) were signs of low genetic differentiation, and they led to the clustering of S. brasiliensis from Canoas I and Canoas II. This suggests that the species is genetically structured as a single population. Some findings indicate that this population of S. brasiliensis comes from the Capivara Reservoir (Canoas I downstream), probably fed by the Tibagi and Cinzas Rivers. Literature data denote that after fish transposition by passage ladders of the Canoas Complex, the migratory species are not concluding the reproductive cycle. This mechanism, therefore, could be one more impact factor causing the depletion in downstream recruitment, which could in medium and long term be compromising the natural S. brasiliensis population in the middle Paranapanema River.

In this study, the RAPD technique was used to analyze the genetic structure of populations of the fish Astyanax altiparanae (Characidae, Tetragonopterinae) living in the lower, middle and upper Paranapanema River, Brazil. The aim was to assess this structure regarding fish handling and conservation programs. The genetic variability (P) was found to be 42.64%, 75% and 75% in the low, middle and upper reaches, respectively. The dendrogram of genetic similarity, obtained by comparative analysis of the sets of samples from the three sites, showed the formation of three clusters. All of the genetic parameters used indicate that the population in the lower Paranapanema is genetically different from those in the middle and upper sections. The theta P test shows that the low Paranapanema is highly differentiated from the middle (0.2813) and upper (0.2912) Paranapanema, while the differentiation between the last two is moderate (0.0895). The data obtained in the present work suggest that recolonization and conservation studies should not be focused on the species A. altiparanae as such, but on the conservation units, because they are the genetically differentiated populations.

Pimelodus maculatus populations from the Tietê and Paranapanema rivers were sampled and had their genetic structure analyzed by using RAPD markers, with the aim of contributing to future conservation studies. The proportion of polymorphic loci was greater than 50% in the populations of both rivers. Genetic diversity data showed that, in spite of its nine hydroelectric plants, the Tietê river population was genetically homogeneous, whereas the Paranapanema river population was structured. This might be due to the presence of high waterfalls distributed all along its course. These data may serve as indicators for future conservation studies on the Tietê and Paranapanema rivers.