(Lamark, 1819) is an epibiont filter feeder bivalve. Its fast growth and fast gonadal recovery depend on the amount and quality of the food ingested by the animal, mainly composed of phytoplankton cells. In the coast of Paraná State, Brazil, several aquaculture farms of C. brasiliana can be found along the Paranaguá Estuarine Complex (PEC) and Guaratuba Bay. Therefore, this work had as objectives to evaluate the taxonomic composition and cell size of the microalgae ingested by adults of the oyster C. brasiliana and to describe its reproductive characteristics (index of meat revenue and stages of gonadal maturation). Oysters cultivated in the PEC were acquired monthly from the Municipal Market of Paranaguá. The oysters (n=30) were then measured and shell length values (SL), height (SH) and gross weight (GW) obtained. Gonadal maturation stages were evaluated through the macroscopic examination of the gonads and revenue index (R) through the wet weight of meat. The digestive gland was removed for the microscopic analysis of the stomach content (i.e. identification and measurement of the microalgae). The highest mean R value (12.79 %) was observed in July 2007, when a great portion of the population presented full gonads, although the predominance of individuals with full gonads (partially full and full) occurred in periods of warmer waters. The genera found in the digestive tract were: Nitzchia, Gyrosigma, Navicula, Pleurosigma, Thalassionema, Frustulia, Anomoeoneis, Chroococcus, Cocconeis, Diploneis, Cyclotella, Coscinodiscus and Prorocentrum, with the cell size varying from 5 to 260 µm.
Opsanus beta is endemic to the Gulf of Mexico and has recently been introduced to the Brazilian coast; probably the introduction is via ballast water and/or oil rigs. In this study, the presence of the species is recorded for the first time in Guaratuba Bay, on the southern coast of Brazil. In this region there are no port terminals, which suggests that O. beta used a different mode of human‐facilitated transport to colonize Guaratuba Bay.
Microplastics represent an emerging global threat to freshwater ecosystems and studies in floodplains are still incipient. Microplastics in the Pantanal’s affluent and floodplains were sampled close to their potential urban sources and in the Pantanal lowlands. A 68 μm mesh size plankton net, with a 150 ml collection flask was used for sampling. The flask content was filtered over a 0.45μm Whatman paper, 47 mm in diameter, and examined under a stereomicroscope at 45X to identify and count microplastics (expressed as n100L-1). Microplastic sizes were determined by image microscopy. The average microplastic size was 192±142 μm and it was not significantly different in the urban tributaries (206±158 μm) than in the Pantanal (181±131 μm). The average±std microplastic concentration was 9.6±8.3, ranging from 1 to 31 n100L-1. Fibers, fragments, pellets, and XPS (closed-cell extruded polystyrene foam) particles represented respectively 50%, 19%, 22% and 9% of the total microplastics. Microplastics concentrations were higher in the urban tributaries (19.9±5.8 n100L-1) than in the Pantanal lowlands (4.5±2.5 n100L-1). Fibers were always the most important fraction, followed by fragments. In the lowlands, pellets were scarce and XPS were absent. Comparison between microplastic composition in the floodplain and the urban areas suggest that pellets are transported from the urban area to the Pantanal, while microfibers and fragments could both be transported from the urban areas and have a local origin. These results indicate that microplastics are contaminating the Pantanal and its affluents and eventually can affect the local fauna. More research is needed to understand the extent and possible implications regarding the contamination by microplastics of the aquatic and terrestrial ecosystems of the Pantanal.
Copepods have a major role in zooplankton communities worldwide and are very important in Polar ecosystems; they form the base of the trophic web, contributing through accumulation of great energy reserves. For this work, fifty five samples were collected in Admiralty Bay, King George Island, Antarctica during the summer of 2009. A total of 15,328 copepods were sorted, Rhincalanus gigas, Macrosetella gracilis, Clausocalanus sp. and another five taxa were identified.
Microplastics represent an emerging global threat to freshwater ecosystems and studies in floodplains are still incipient. Microplastics in the Pantanal’s affluent and floodplains were sampled close to their potential urban sources and in the Pantanal lowlands. A 68 μm mesh size plankton net, with a 150 ml collection flask was used for sampling. The flask content was filtered over a 0.45μm Whatman paper, 47 mm in diameter, and examined under a stereomicroscope at 45X to identify and count microplastics (expressed as n100L-1). Microplastic sizes were determined by image microscopy. The average microplastic size was 192±142 μm and it was not significantly different in the urban tributaries (206±158 μm) than in the Pantanal (181±131 μm). The average±std microplastic concentration was 9.6±8.3, ranging from 1 to 31 n100L-1. Fibers, fragments, pellets, and XPS (closed-cell extruded polystyrene foam) particles represented respectively 50%, 19%, 22% and 9% of the total microplastics. Microplastics concentrations were higher in the urban tributaries (19.9±5.8 n100L-1) than in the Pantanal lowlands (4.5±2.5 n100L-1). Fibers were always the most important fraction, followed by fragments. In the lowlands, pellets were scarce and XPS were absent. Comparison between microplastic composition in the floodplain and the urban areas suggest that pellets are transported from the urban area to the Pantanal, while microfibers and fragments could both be transported from the urban areas and have a local origin. These results indicate that microplastics are contaminating the Pantanal and its affluents and eventually can affect the local fauna. More research is needed to understand the extent and possible implications regarding the contamination by microplastics of the aquatic and terrestrial ecosystems of the Pantanal.
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