widespread use of nanosilver can be led the contamination of aquatic environment and impact on living organisms such as fishes. we investigated histopathological changes in the gills tissue of caspian roach fingerlings after two weeks exposure to sublethal concentrations of nanosilver. following one and two weeks exposure, necrosis, shortening of secondary lamellae, edema, destruction of epithe...

oligochaeta worms are important organisms in aquatic ecosystem. their omnipresence makes them as an indicator of environmental changes and health of aquatic ecosystem. the members of the family tubificidae and in particular, genus limnodrilus are considered as the most tolerant oligochaets to aquatic pollution. therefore identification and biological characteristics of this taxon are of great h...

Oligochaeta worms are important organisms in aquatic ecosystem. Their omnipresence makes them as an indicator of environmental changes and health of aquatic ecosystem. The members of the family Tubificidae and in particular, genus Limnodrilus are considered as the most tolerant oligochaets to aquatic pollution. Therefore identification and biological characteristics of this taxon are of great h...

Toxigenic Vibrio cholerae is the etiological agent of cholera, an acute dehydrating diarrhoea that occurs in epidemic form in many developing countries. Aquatic ecosystem is the major habitat of toxigenic V. cholerae, where it interacts with various abiotic and biotic factors to survive. To acknowledge the seasonal appearance, endemic nature and genetic deviation of V. cholerae it is essential ...

1. Ecosystems may affect each other through trophic interactions that cross ecosystem boundaries as well as via the transfer of subsidies, but these effects can vary depending on the identity of species involved in the interaction. 2. In this study, we manipulated two terrestrial bromeliad-living spider species (Aglaoctenus castaneus, Corinna gr. rubripes) that have variable hunting modes, to t...

Wide occurrence of aquatic metal pollution has caused much attention. Biomonitoring offers an appealing tool for the assessment of metal pollution in aquatic ecosystem. The bioindicators including algae, macrophyte, zooplankton, insect, bivalve mollusks, gastropod, fish, amphibian and others are enumerated and compared for their advantages and disadvantages in practical biomonitoring of aquatic...

Ab$tract.--Riparian vegetation is very important in determining the structure and function of stream ecosystems. Most aquatic organisms, both invertebrates and fish, are directly or indirectly dependent on inputs of terrestrial detri tus to the stream for their food. Natural changes in riparian vegetation and the biotic processing of detritus, as well as other factors, determine the kinds and a...

Many non-native aquatic species have been introduced into the United States. Some benefit society by providing food, recreational opportunities, and the associated socio-economic activity. But some introduced species that have escaped or been released are undesirable additions to aquatic ecosystems because they cause ecological or economic harm or are dangerous to human health. These are called...

Introduction Conclusions References