26 Arsenic (As) exists in a variety of chemical forms, and microbial metabolism results in 27 the occurrence of thermodynamically unstable arsenite (As) and methylarsenic compounds 28 in freshwaters (rivers and lakes). The inorganic forms (As and As) and the methylated 29 forms (methylarsonic acid; MMAA and dimethylarsinic acid; DMAA) are the main species 30 of As in freshwaters while the bulk ...

1. Some features of the osmoregulatory mechanism are compared in four populations of Paranephrops zeal andicus White collected form freshwaters of different ionic concentrations. 2. Crayfish from freshwaters of ca, 2-0 mM-NaCl concentration show a sustained decrease in blood concentration of ca. 8% when placed in 0-2 mM-NaCl. 3. Populations from freshwaters of ca. 0-2-0-4 mM-NaCl show lower rat...

Aerobic ammonia oxidation plays a key role in the nitrogen cycle, and the diversity of the responsible microorganisms is regulated by environmental factors. Abundance and composition of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) were investigated in the surface waters along an environmental gradient of the Yong River in Ningbo, East China. Water samples were collected ...

A review of results published in English or French between 1980 and 1990 was carried out to determine the levels of indigenous human enteric viruses in untreated surface and subsurface freshwaters, as well as in drinking water that had undergone the complete conventional treatment process. For this purpose, the conventional treatment process was defined as an operation that included coagulation...

Inland waters (lakes, reservoirs, streams, and rivers) are often substantial methane (CH(4)) sources in the terrestrial landscape. They are, however, not yet well integrated in global greenhouse gas (GHG) budgets. Data from 474 freshwater ecosystems and the most recent global water area estimates indicate that freshwaters emit at least 103 teragrams of CH(4) year(-1), corresponding to 0.65 peta...

twenty-seven species of odonata were collected in the present survey in the freshwaters of south-eastern iran, kerman province, in contrast to 11 species that were recorded previously from this region. in this study, 528 specimens were collected from more than 30 sites in kerman province during 2006-2008. it seems that in this region due to its special biogeographic conditions, species diversit...

in the present study, we reported infection with eighteen species of the genus dactylogyrus, belong to thefamily dactylogyridae from five breeder fish species, including common carp (cyprinus carpio), grass carp(ctenopharyngodon idella), silver carp (hypophthalmichthys molitrix), big head carp (hypophthalmichthysnobilis) and black carp (myelopharyngodon piceus) which introduced and imported to ...

More freshwater ecosystems are drying in response to global change thereby posing serious threat to freshwater biota and functions. The production of desiccation-resistant forms is an important adaptation that helps maintain biodiversity in temporary freshwaters by buffering communities from drying, but its potential to mitigate the negative effects of drying in freshwater ecosystems could vary...