This work addresses the relationships between Land Use/Land Cover (LULC) and water quality in the Paraíba do Sul River (PSR), located in one of the most populated regions in Brazil. We conducted a water sampling program (analyzing nitrate, ammonium, phosphate, turbidity, total carbon, oxygen concentration, and conductivity) during a severe drought period from 2014 to 2016. The 210 samples were spaced about 5 km apart from headwaters to the Atlantic Ocean and taken over 63 d. We calculated a water quality index and applied a self‐organizing map (SOM) to explore the relationship between LULC and water quality. There was a significant influence on water quality from the urban area's socioeconomic profile. This observation reflects the influence of cities with a high population density and a low economic condition, which leads to further degradation and erosion of the riverbanks. The most degraded reservoir of the PSR (Funil) partially buffers these effects by retaining deposited sediments and nutrient loads, leading to downstream water quality improvement. Better management practices of the riverbanks in the lower reach contribute to additional water quality improvements. Three major clusters identified using the SOM had completely different and explainable water quality patterns, suggesting an abrupt change in water quality due to human interventions. This information is crucial to improve management projects for the river at a watershed level, and with the expectation of future water shortages.

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Feeding is an important factor for the successful rearing of larvae of the crab species. Further information on the morphological features of the foregut may to reveal larval feeding behaviour and or/whether there is a lecithotrophy in some or even in all stages of the larval cycle. In the present study, the structural development of the foregut and their digestive functions were examined in larvae of two brachyurans, Uca vocator and Panopeus occidentalis, reared in the laboratory. During larval development, the foreguts of the larvae in the first and last zoeal stages and in the megalopa stage were microscopically examined, described and illustrated. The zoeal foreguts of both species were well developed, showing specialization with a functional cardiopyloric valve and a filter press. The megalopa stage had a complex and specialized gastric mill similar to that found in adult crabs with the appearance of rigidly calcified structures. These results support the hypothesis that the feeding behaviour of each larval stage is directly related to the morphological structure of the foregut. Such facts strongly indicate that all larval stages of both U. vocator and P. occidentalis need an external food source before completing the larval development in a planktonic environment.

For over a century, Lepidosiren paradoxa has been recognized as the single lungfish species in South America. Previous studies have failed to identify morphological differences in lungfish populations inhabiting the Amazon and Paraná-Paraguay River basins. Here, we report molecular evidence of cryptic speciation in South American lungfish. Our analysis of mitochondrial gene sequences from 56 L. paradoxa individuals collected in the Amazon and Paraná-Paraguay river systems revealed that genetic distances between individuals from different basins were on average 20 times greater than those obtained for individuals that occur in the same basin. Haplotype network did not uncover shared haplotypes between basins. Additionally, the species delimitation analysis showed that the posterior probability for the existence of distinct species is highly significant (PP = 0.99961). The phylogenetic analyses (BI and ML) recovered individuals from distinctive basins in reciprocally monophyletic clades. Our divergence time estimate suggests that the Lepidosiren in the Amazon basin are seven million years split from those that occur in the Paraná-Paraguay basin. On the other hand, in agreement with previous reports, our morphological comparison of 20 specimens from the Amazon and 14 specimens from the Paraná-Paraguay basins revealed no distinctive morphological features. The combined molecular and morphological results suggest that these two forms may represent cryptic species.

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Caracterização da subsuperfície e análise da qualidade de água para consumo na Vila de São Joaquim do Ituquara (Baião, Pará, Brasil) Characterization of the subsurface and analysis of the quality of the water used for human consumption in the village of São Joaquim do Ituquara (Baião, Pará, Brazil

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