The retention of plastic particles by macrophytes in the Amazon River, Brazil.

This study evaluated the presence of plastics and microplastics in macrophytes in an urbanized sector of the Amazon River. A total of 77 quadrats in 23 macrophyte banks were sampled during the dry (September 2020) and rainy (June 2021) season. Five species were identified: Paspalum repens, Pontederia rotundifolia, Pistia stratiotes, Salvinia auriculata and Limnobium laevigatum, with P.

Microplastic contamination in bathing areas in the Central Amazon, Itacoatiara, Brazil.

Due to the visible abundance of plastic improperly disposed of in the environment, the number of investigations has increased worldwide in different water bodies and biota. Despite this, studies of contamination by microplastics in freshwater environments in the Amazon are scarce. This study investigated microplastic contamination in sediment samples of bathing areas in the Central Amazon, in Itacoatiara, Amazonas, Brazil.

Microplastic contamination in the freshwater shrimp Macrobrachium amazonicum in Itacoatiara, Amazonas, Brazil.

The present study analyzed the presence of microplastics (MPs) in the shrimp Macrobrachium amazonicum, which is an economically important food that is consumed in several regions of the Brazilian Amazon. A total of 600 specimens of M. amazonicum were captured at two sampling sites (urban and rural area).

Gastropod shell size and architecture influence the applicability of methods used to estimate internal volume.

Obtaining accurate and reproducible estimates of internal shell volume is a vital requirement for studies into the ecology of a range of shell-occupying organisms, including hermit crabs. Shell internal volume is usually estimated by filling the shell cavity with water or sand, however, there has been no systematic assessment of the reliability of these methods and moreover no comparison with modern alternatives, e.g.

Morphological changes in the seminal receptacle during ovarian development in the speckled swimming crab Arenaeus cribrarius.

To understand sperm plug dissolution and spermatophore dehiscence in Portunidae, histological and ultrastructural changes in the seminal receptacle (SR) of Arenaeus cribrarius were investigated during ovarian development. In juvenile females the SR was filled with acid polysaccharides and the dorsal epithelium was stratified. Mated females with rudimentary ovaries showed a large SR filled by a glycoprotein sperm plug.

Effects of tributyltin exposure in hermit crabs: Clibanarius vittatus as a model.

Tributyltin (TBT) contamination affects the reproductive system of many species of invertebrates worldwide. The present study was designed to evaluate the effects of exposure to TBT pollution on the reproduction of the hermit crab Clibanarius vittatus. An orthogonal experiment was designed with two treatments: contamination (with or without TBT in the food) and crab sex (males and females).