This study explored the possibility that environmental estrogens in sewage effluent may reduce the reproductive fitness of adult male fish by suppressing their reproductive behaviors, including their ability to compete for nests and females. Male fathead minnows (Pimephales promelas) were exposed for three weeks to either blank control, effluent released by a sewage treatment plant (STPE), wate...

Four pulp and paper mills discharge their effluents in the same section of the Biobio River in central southern Chile. Pulp mill effluents are a very complex mixture with characteristics that depend on the type of raw material, the process technology, and the effluent treatment. To investigate the effect of pulp mill effluent discharges, immature Oncorhynchus mykiss were exposed to river sedime...

Many fish use steroid hormones as pheromones to initiate behavioral and physiological changes during spawning. To assess the occurrence of steroid hormones with pheromonal properties in the aquatic environment and to evaluate the possibility that municipal wastewater discharges contain compounds that could affect fish reproduction by interfering with pheromones, several estrogens, androgens, an...

The goal of this study was to assess the responses of fathead minnows (FHM) exposed to known endocrine-disrupting substances (EDS) in our labs. As well, we wanted to examine the applicability and sensitivity of the full lifecycle FHM test for use on-site, exposing fish to a complex environmentally relevant Canadian effluent. Fathead minnows exposed from the egg stage to ethinylestradiol (EE2, 0...

We studied the acute toxicity of a raw effluent from a battery manufacturing plant (Pilcam) in Douala, Cameroon, to a freshwater fish (Oreochromis niloticus), and subsequently evaluated its sub-acute effects on water quality and the biota in freshwater microscosms. The acute toxicity test was based on 96 hrs static renewal bioassays that resulted in 96-h LC50 and LC90 values of 16 and 20.7% (v/...

Adult male fathead minnows (Pimephales promelas) were exposed to effluent from the City of Boulder, Colorado wastewater treatment plant (WWTP) under controlled conditions in the field to determine if the effluent induced reproductive disruption in fish. Gonadal intersex and other evidence of reproductive disruption were previously identified in white suckers (Catostomus commersoni) in Boulder C...

Studies were undertaken to record distillery effluent induced quantitative alterations in the nucleic acids (DNA & RNA) and protein during three principal phases of ovarian cycle (prespawning, spawning and post spawning) of Colisa fasciatus , a tropical freshwater fish. Observation were recorded under three different concentrations of the distillery effluent after 30 days of exposure. Observati...

The fresh water fish Rasbora daniconius were exposed to two sublethal concentration of sugar factory effluent for 4 weeks studied. The concentration were record 1/5(2.2%) and 1/10(1.1%) of the 96 hrs LC 5O values of sugar factory effluent. The gills of R. daniconius showed the curling and degeneration and breaking of epithelium cells of the secondary gill lamellae, destruction of blood cells, b...