in order to understand the importance of particle size and agglomeration for nano-eco-toxicological studies in aquatic environments, the acute toxicity of two different types (suspended powder and colloidal) of silver nanoparticles (agnps) were studied in alevin and juvenilerainbow trout. fish were exposed to each type of agnps at nominal concentrations of 0.032, 0.1, 0.32, 1, 3.2, 10, 32, and ...

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) is a widespread environmental contaminant that causes multiple effects in vertebrates. TCDD elicits its toxicity through aryl hydrocarbon receptor (AhR)-mediated modulation of gene regulation, increasing intracellular free calcium, and inducing calcium-mediated apoptosis in cell culture. Two TCDD-responsive cDNAs, which encode putative calcium-...

vast application of the antibiotic drugs in animals without due attention  to withdrawal times necessitates quality control of food stuff in terms of antibiotics' residues. antibiotic residues in food stuff cause bacterial resistance, allergic reactions, toxicity,  carcinogenic effects and change of natural micro flora of intestine in consumers. so, the aim of the present study is detectio...

Bull trout (Salvelinus confluentus) were recently listed as threatened in the United States under the federal Endangered Species Act. Present and historical habitat of this species includes waterways that have been impacted by metals released from mining and mineral processing activities. We conducted paired bioassays with bull trout and rainbow trout (Oncorhynchus mykiss) to examine the relati...

Clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) is a pyridine herbicide frequently used to control invasive, noxious weeds in the northwestern United States. Clopyralid exhibits low acute toxicity to fish, including the rainbow trout (Oncorhynchus mykiss) and the threatened bull trout (Salvelinus confluentus). However, there are no published chronic toxicity data for clopyralid and fish tha...

The rainbow trout endocrine system is sensitive to changes in annual day length, which is likely the principal environmental cue controlling its reproductive cycle. This study focuses on the endocrine regulation of vitellogenin (Vg) protein synthesis, which is the major egg yolk precursor in this fish species. We present a model of Vg production in female rainbow trout which incorporates a biol...

From the large data set available on the toxicity of boron to aquatic organisms, the toxicity of boron to the early life stages of rainbow trout (Oncorhyncus mykiss) is the seminal issue relative to setting water quality criteria and effluent standards. Issues associated with the early life stage studies are the flat concentration-response curve, the low threshold of toxicity, and teratogenic e...

The acute toxicity of cadmium, copper, and zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) were determined for 7 developmental life stages in flow-through water-only exposures. Metal toxicity varied by species and by life stage. Rainbow trout were more sensitive to cadmium than white sturgeon across all life stages, with median effect concentrations (har...

Flow-through toxicity tests were conducted on common freshwater fishes: rainbow trout (Oncorhynchus mykiss), three-spined stickleback (Gasterosteus aculeatus), roach (Rutilus rutilus), perch (Perca fluviatilis) and dace (Leuciscus leuciscus), to estimate their sensitivity to acute toxicity of nickel. The 96-hour median lethal concentration (96-hour LC50) values obtained from the tests ranged fr...

Previous studies in rainbow trout have shown that acclimation to hypersaline environments enhances the toxicity to thioether organophosphate and carbamate pesticides. In order to determine the role of biotransformation in this process, the metabolism of the thioether organophosphate biocide, fenthion was evaluated in microsomes from gills, liver and olfactory tissues in rainbow trout (Oncorhync...