Quantifying and classifying ichthyoplankton is one of the most effective ways of monitoring the recruitment process in fishes. However, correctly identifying the fish based on morphological characters is extremely difficult, especially in the early stages of development. We examined ichthyoplankton from tributaries and reservoirs along the middle stretch of the Paranapanema River, one of the areas most impacted by hydroelectric projects in the Neotropics. Matching DNA sequences of the COI gene (628-648 bp) allowed us to identify 99.25% of 536 samples of eggs (293) and larvae (243) subjected to BOLD-IDS similarity analysis with a species-level threshold of 1.3%. The results revealed 37 species in 27 genera, 15 families and four orders, some 23.8% of documented fish species in the Paranapanema River. Molecular identification meant that we could include data from egg samples that accounted for about 30% of the species richness observed. The results in this study confirm the efficacy of DNA barcoding in identifying Neotropical ichthyoplankton and show how the data produced provide valuable information for preparing plans for conserving and managing inland waters.

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.

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.

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.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.

RESUMOA obesidade infantil, considerada uma pandemia, apresenta custos sócio-econômicos significativos por sua elevada morbimortalidade. Para avaliar a associação entre fatores biológicos e ambientais e a presença de hipertensão arterial (HA), realizou-se estudo transversal com 701 crianças, de 5 a 9 anos, de Feira de Santana, BA. A pressão arterial foi mensurada conforme parâmetros do Update on the 1987 Task Force Report on High Blood Pressure in Children and Adolescents. Definiu-se sobrepeso e obesidade como índice de massa corpórea≥ aos percentis 85 e 95 para idade e sexo, respectivamente. A análise de entrevistas com os responsáveis possibilitou estudo das variáveis sexo, etnia, idade, história familiar para HA e escola freqüentada. Observados como fatores preditivos independentes para HA a presença de sobrepeso (OR= 4,49; ρ= 0,04), obesidade (OR= 13,05; ρ= 0,000) e o fato de estudar em escola privada (OR= 1,93; ρ= 0,13), sugerindo um papel importante de fatores biológicos e ambientais na gênese da HA em crianças. Childhood obesity is considered pandemic with significant social and economical costs because of its high morbidity and mortality. To evaluate the association between biological and environmental factors and infantile arterial hypertension (AH), a cross-sectional study was performed with 701 children, ranging from 5 to 9 years old, from Feira de Santana, BA. The arterial pressure was measured following the criteria of the Update on the 1987 Task Force Report on High Blood Pressure in Children and Adolescents. Overweight and obesity were defined as bodymass index equal or above the 85 th and the 95 th percentiles for age and gender, respectively. Interviews with the children's responsible were used to determine the role of gender, ethnic group, age, familiar history of AH, and type of school. Overweight (OR= 4.49; ρ= 0.04), obesity (OR= 13.05; ρ= 0.000) and studying at private school (OR= 1.93; ρ= 0.13) were observed as predictive and independent factors associated with hypertension. Therefore, biological and environmental factors seem to be involved on the genesis of AH in children.