Effect of sublethal concentration of anionic detergent on feeding behavior of Daphnia magna

Daphnia magna was exposed to the concentration 1/4, 1/2 and 2/3 LC50 and LC50 of 6 anionic detergents to determine the effect of these detergents on filtration and ingestion rates. Two dish washing liquid in terms of active ingredient as linear alkyl benzene sulfonate each 17% but one with DE ethanolamine (5%) and lauric acid ethanolamid (2%) as its component part, including washing machine powder, two kind washing powders and a shampoo, which the last four active ingredients content were 10%, 19%, 20 - 22%, 12% respectively exposed to the test organism. The experiments were performed with unicellular algae Chlorella vulgaris in a density of 10 mg/l as a feed to Daphnia magna. Relatively simple short term bioassay methods were developed to measure the filtration and ingestion (5 hours) rate. The effective concentration at which feeding and ingestion rates were reduced to 50% of those in controls (LC50) was calculated for six detergents. These values were 9.87, 4.37, 22.8, 33.17, 21.81, 35.26 mg/l for feeding rate and 9.75, 5.67, 19.9, 44.26, 23.94, 43.41 mg/l for ingestion rates respectively. The results indicated the liquid detergents exerted high reduction in feeding and ingestion rates and the one with the ingredients of DE-ethanolamine (5%) and lauric acid (2%) influenced higher in reduction of feeding and ingestion rate. The effect of washing powder were greater to the feeding behaviour in comparison with washing machine powder, the shampoo observed with many limited effect on filtration and ingestion rates

The lethal effect of detergent on Microcyclops sp.

Microcyclops sp. was exposed to selected detergents (two dishwasher detergents, one washing-powder, one washing-machine powder and one shampoo) for 24 hours. The results indicated the dishwasher powder had higher lethal effect on Microcyclops sp. than the other examined detergents, especially one containing 17% Linear Alkyl Benzene Sulfonate, 5% Di-Ethanolamine and 2% Lauric Acid. The permissible concentration and the LC50 for the dishwasher powder is 7.84 and 13.32 mg/l respectively. Among the powders the washing-machine powder appeared to be least lethal (LC50 = 43.87 mg/l) and the shampoo with LC50 of 47.27 mg/l had the lowest lethal effect on Microcyclops sp.. Correlation rate of the detergent concentration logarithm and the mortality of Microcyclops sp. ranged between 94-98%

The impact of detergents on the mortality of Daphnia magna

This study aimed to examine the impact of detergents on the mortality rate of Daphnia magna. For this purpose, we exposed one-day-old Daphnia magna for 24 hours to six nationwide consumed detergents, comprising of two dishwasher detergents, three washing-powders (one for hand wash and two for washing-machines) and one shampoo. The result of our study revealed that the dishwasher detergents had the greatest impact on the Daphnia magna mortality. One of these detergents containing 17% Linear Alkyl Benzene Sulfonate, 5% Deethanolamine and 2% Lauric acid Ethanolamid was the most lethal detergent in this study. The permissible concentration and the EC50 of this dishwasher detergent is 4.7 mg/1 and 7.5 mg/1, respectively. Studies in 1993 indicated that the concentration of Linear Alkyl Benzene Sulfonate in some part of Anzali Lagoon had been 8.9 mg/1, which is above the permissible level. Among the washing-powders, the washing-machine powders were the least lethal detergents for Daphnia magna (EC50 = 50.9), while the only tested shampoo was the least lethal (EC50 = 52) detergent for Daphnia magna correlation coefficient between logarithm of concentration of the detergents and the mortality rate of Daphnia magna were 79% - 99%

The role of CA1 α-adrenoceptor on scopolamine induced memory impairment in male rats

Introduction: Similarities in the memory impairment between Alzheimer patients and scopolamine treated animals have been reported. In the present study, the possible role of α-adrenergic receptors of the dorsal hippocampus on scopolamine state-dependent memory in adult male Wistar rats was evaluated. Methods: The animals were bilaterally implanted with chronic cannulae in the CA1 regions of the dorsal hippocampus, trained in a step-through type inhibitory avoidance task, and tested 24 h after training to measure step-through latency. Results: Post-training intra-CA1 administration of scopolamine (0.5 and 2μg/rat) dose-dependently reduced the step-through latency, showing an amnestic response. Amnesia produced by post-training scopolamine (2 μg/rat) was reversed by pre-test administration of the scopolamine (0.5 and 2 μg/rat) that is due to a state-dependent effect. Pre-test intra-CA1 injection of α1-adrenoceptor agonist, phenylephrine (0.25, 0.5 μg/rat) in the dose range that we used, could not affect memory impairment induced by post-training injection of scopolamine (2 μg/rat). However intra-CA1 pretest injection of α2-adrenoceptor agonist, clonidine (0.5 μg/rat) improved post-training scopolamine (2 μg/rat) intra-CA1 injection induced retrieval impairment. Furthermore, pre-test intra-CA1 microinjection of phenylephrine (0.25 and 0.5 μg/rat) or clonidine (0.25 and 0.5 μg/rat) with an ineffective dose of scopolamine (0.25 μg/rat), synergistically improved memory performance impaired by post-training scopolamine (2 μg/rat). Our results also showed that, pre-test injection of α1-receptor antagonist prazosin (1, 2 μg/rat) or α2-receptors antagonist yohimbine (1, 2 μg/rat) before effective dose of scopolamine (2 μg/rat) prevented the improvement of memory by pre-test scopolamine. Conclusion: These results suggest that α1- and α2-adrenergic receptors of the dorsal hippocampal CA1 region may play an important role in scopolamine-induced amnesia and scopolamine state-dependent memory

Effect of chemical herbicides and insecticides on mortality and feeding of silver carp (Hypophthalmichthys molitrix)

Fingerlings of Silver Carp (Hypophthalmichthys molitrix) were used in an ecotoxicological investigation. The fish were exposed to (0.3-10 mg/l) Machete, (3-5 mg/l) Saturn, (1.5-13 mg/l) Diazinon and (1-10 mg/l) Malathion to measure the toxicity effect of these chemicals on mortality, feeding and ingestion rate. Methods for investigation on mortality were according to TRC (1984) and feeding behavior, according to Gould Equation (1951). Porbit analysis was used for evaluation of obtained data. LC10 of these toxic compounds were 0.17-0.23, 2.85-3.73, 0.6-0.95, 0.87-1.34 mg/l for Machete, Saurn, Diazinon and Malathion respectively. Experiments showed that Machete and Diazinon in comparison with Saturn and Malathion were highly toxic for fingerlings of silver carp. At first fish showed to be disturbed, then moved rapidly and exhausted. A secretion of excess mucus was also noticed and eye-ball became expanded. There was also blanching of the skin. The fish surfaced sometimes on their side and became unbalanced which resulted in death. Abnormal behavior of fish became greater with the increase of pesticides concentration. In these exposures pH was decreased, in contrast with the amount of water hardness. LC10, LC50 and LC90 form 24 to 96 hours were mostly decreased. Feeding experiments showed that 8 hours exposure below the LC50 values reduced 50 percent of feeding and ingestion rates

Effects of herbicides on Selenastrum capricornutum and Daphnia magna

The toxicity of five herbicides, Propanil, Machete, Rilof-H, Saturn, and Ronestar, commonly used in Iranian rice fields, were investigated in acute toxicity bioassays on two organisms belonging to different in aquatic food chain. Compared with Daphnia magna, green algae Selenastrum capricornutum, showed more sensitivly to the herbicides. Machete and Saturn were the most toxic herbicides for algae. Three other herbicides, having more effect on the toxicity rate were Ronestar, Rilof-H, and Propanil. The toxic herbicides for Daphnia magna were Rilof-H and Saturn, and the others showed less toxicity. Comparing the amount of 6 to 23 mg/1 field concentrations of the herbicides with 0.01 to 12.46 mg/1 MAV-values for Selenastrum capticomutum and 0.446 to 9.5 mg/1, MAC-values for Daphnia magna in laboratory experiments revealed that the herbicides would certainly kill all useful organisms in aquatic food chain such as algae and zooplanktons in rice fields, and would damage other neighboring ecosystems in rivers, reservoirs, lagoon and the Caspian Sea which are connected with the fields. Ministry of Agriculture should be asked to introduce other less toxic herbicides

Short communication: Survey of Methyl Tertiary Butyl Ether (MTBE) toxicity using bioassay on Daphnia magna

In this study, the toxicity of MTBE on the crustacean Daphnia magna (Cladocera) has been studied. At the beginning, for finding the range of sensitivity of D. magna to MTBE, a test had been conducted at 24h. The initial and final tests with synthetic MTBE has been done with containing solutions of water accommodated fractions (WAFs) in periods of 24 and 48h and then static bioassay was calculated in two phases of tests and the data were obtained and analyzed by SPSS 13 by using probit analysis. In 24h, lc10, lc50 and lc90 for MTBE on D. magna were 345, 646 and 941mg/l and for 48h, they were 361, 476 and 893mg/l, respectively. Also, the maximum allowable concentration (MAC) of MTBE (WAFs) on D. magna was determined in 24 and 48h, 64.6 and 47.6mg/l, respectively. Results indicated that D. magna could be used for toxicity tracing MTBE in surface and ground water, because these crustaceans have perfect resistance against pollution of MTBE. It is also concluded that after 24 and 48h exposure time, there was no significant difference observed in the activity and mortality of D. magna

Determining the lethal concentration (LC50 96h) of butachlor herbicide for Acipenser persicus and Acipenser stellatus fingerlings

The toxic effects of the herbicide Butachlor were studied using a concentration of 0.4-1.3ppm and 0/1-1ppm on fingerlings of the Persian sturgeon, Acipenser persicus, and Stellatus sturgeon, Acipenser stellatus, respectively in 1999. We carried out six treatments with three replicates and used one control based on the static O.E.C. D. method. Over the experiments, pH ranged between 6.7 -8.2, total hardness was measured to be 230 mg/l, water temperature was 20 plus or minus 1 degrees centigrade and dissolved oxygen was above 6 mg/l. We found that the LC50 96h of the Butachlor on fingerlings of the Persian sturgeon, Acipenser persicus, and Stellatus sturgeon, Acipenser stellatus, weighing 1-3 grams was 0.44 and 0.07 mg/l respectively. Also assessed the LC10, LC50, LC90 of the herbicide on the fingerlings of the sturgeons using the Probit Analysis procedure. We determined the maximum allowable concentration of the Butachlor herbicide for the fingerlings of the Persian sturgeons, Acipenser persicus, and Stellatus sturgeons, Acipenser stellatus, to be 0.044 and 0.007 mg/l. Based on the standards, the herbicide is considered highly toxic for the studied fingerlings

Effects of diazinon, malathion, machete and saturn on mortality of fingerling of Rutilus frisii kutum

The toxicity of the pesticides, malathion and diazinon, and the herbicides, Machete and Saturn, on mortality of fingerling of Rutilus frisii kutum were examined. Lc10 values for diazinon, Malathion, Machete and Saturn were 0.14 - 0.24, 0.10 - 0.35, 0.14 - 0.55, and 1.45 - 2.50 mg/L respectively. The result showed that diazinon, malathion and machete have a highly toxic effect on fingerling of R. frisii kutum and the herbicide, saturn, in comparison with other poisons was less toxic

Morphometric analysis of the common carp, (Cyprinus carpio Linnaeus, 1758) in Anzali Lagoon, south west Caspian Sea

We used electroshocker, cast net and gillnet twice a week in four areas of Anzali Lagoon from April to September 2001 to sample common carp (Cyprinus carpio). Specimens were subjected to biometric measurments in the lab. In all, eighteen morphometric and seven meristic measurements were done on the samples. We determined the equation for the fish total fork length and body weight for males and females. Also, Van Bertalanffy growth model was applied to the male and female fish