| Aquatic toxicology is a scientific that study of the toxic effects of poisons on aquatic organisms,migration,transformation and end-result in aquatic environments,and interaction with other environmental factors.All kinds of pollutants enter the water from different ways,not only reduce the quality of aquatic products,cause the death of a large number of aquatic organisms,but also threaten human health,thus causing people's attention and research.Nonylphenol,molecular formula was C15H24O,widely used in production of plastics,synthetic detergent,difficult to degradation in the environment,but also in natural water bodies can through the food chain and enrichment in the aquatic animals,the main way to enter the body has the potential to the drinking water and aquatic animal food.Rotifers is one of the important groups of zooplankton,widely distributed,most species distributed in the world everywhere,it belongs to the Syndermata,high sensitivity to toxicants,and the advantages of short life cycle and propagation speed,so it's often used in ecotoxicology studies.This experiment to choose the subjects of biology is Brachionus calyciflorus,cultured at 25±1?,feeding with a density of 3.0×106 cell/mL of Chlorella pyrenoidosa,the experiment was run at 16L:8D and the illumination intensity was 4000Lx,main research content were:to population density,life table parameters and survival and reproductive rate as evaluation parameters,comparing the different concentration of nonylphenol and maternal exposure time and the different of descendants living environment(with or without the nonylphenol)effects on Brachionus calyciflorus physiological reproductive.This research mainly involved five aspects as follows:1.The effects of different concentrations of nonylphenol on the population dynamic in B.calyciflorus(1)population densityWhen rotifer exposed 0.5,5.0,10.0 and 15.0 ?g/L,the maximum population density were 116,110,100 and 85ind/mL,respectively,the control was 139ind/mL,from the date of experiment,at seven day,the population density of control was reach 100ind/mL,when nonylphenol concentration were 0.5,5.0?g/L,the population density were reach 100ind/mL at eight day,but in the 10?g/L experiment was reach 100ind/mL at ten day,in the 15.0?g/L the population density always below 100ind/mL.Therefore,the high concentration of nonylphenol had inhibition for population growth of rotifer(P<0.05).(2)survival rate,reproductive rate and life table parametersWith the concentration of nonylphenol increase,the death rate was appeared increased trend.From reproduction rate,especially the concentration was 15?g/L,the greatest reproduction rate was 0.6,the control was 1.6,so,compare with the reproduction rate of control was reduced by 62.5 percent,have obvious different with each other(P<0.05).At the survival rate aspect,follow the concentration of Nonylphenol increase(0.5-15?g/L),the survival curve from A(the mortality at advance stage was less than the later stage)to B(at every stage the mortality was not have significant different)and C(at advance stage the mortality was very high)From the life table parameter of rm,R0 and T,all parameter were decline along with the concentration increase,but the sensitivity of parameter was have different,at 5?g/L,the R0 have significant different with control(P<0.05),the parameter of T at 10?g/L was significant reduce(P<0.01),the rm was have significant different with control at 15?g/L concentration(P<0.01),in general,the parameter of R0 have more sensitivity.2.The effect of maternal exposure to nonylphenol on descendant(1)different maternal exposure timeOn the whole,no mater of maternal exposure time,the population density was decrease follow the concentration of nonylphenol increase.First,when female exposure time was 12h,the concentration of nonylphenol was 10,15?g/L,the most popularion density were 83 ind/mL and 65 ind/mL,respectively,compare with control,reduced by 40.29%and 53.24%,respectively(P<0.05).Another maternal exposed time was 24h,same of concentration,the population density were 84 ind/mL and 72 ind/mL,respectively,compare with the control,have reduced by 39.57%and 48.2%,respectively,although have decreased with control(P<0.05),same concentration,different maternal time haven't different about population density(P>0.05),compare with the descendants of no maternal exposed,population density trend was fall,but not have different with each other(P>0.05)From the survival rate,reproductive rate and life table parameters,the survival rate of control was below 40%from 192h,when maternal exposed in 10 and 15?g/L at 12h,the survival rate of offspring was below 40%from 84h and 60h,respectively,compared with control were advanced 56.25%and 68.75%,respectively,have significant different with control(P<0.05);in the same concentration exposed 24h,offspring survival rate from 72h and 60h below 40%,also have significant advanced with control(P<0.05),but different exposed time of maternal not caused significant different on survival of offspring(P>0.05).Secondly,the reproductive rate of control was two offsprings of every female;maternal exposed at 0.5,5.0?g/L 12h and 24h,the reproduced of offspring was almost the same with control,but when the concentration was 15?g/L,whether maternal exposed at 12h or 24h,the offspring most reproduction rate were 0.8 and 1.25,respectively,compared with control were decreased 60%and 37.5%,respectively,have different with control(P<0.05),whenther maternal exposed time,the reproduction rate of offspring was not have significant different with each other(P>0.05).Last was the life table parameter,whether the maternal exposed time,R0,rm and T were decline follow the concentration of NP increase.1,maternal exposed 24h,the decreasing rate of R0 and T of offspring was slow than the offspring of maternal exposed 12h.2,Same concentration different female exposed time,about R0 and T,the parameter of maternal exposed 24h was greater than the maternal only exposed 12h,but the rm was contrary to R0 and T.(2)different descendants living environment(with or without the nonylphenol)From the mortality,the control was from 192h the death rate reach 60%,if offspring continue living in NP of 10.0,15.0?g/L,from 72h and 60h the mortality reach 60%,respectively,compared with control were advanced 62.5%and 68.75%(P<0.05),if offspring living in EPA,was start at 72h and 36h,compared with control were advanced 62.5%and 81.25%(P<0.05),whether offspring living in what environmental,the mortality all have significant different with control(P<0.05),but the offspring of living in different circumstance not have different with each other(P>0.05).Through analyzed and compared the life table parameter,even though the offspring living in EPA,all parameter have decline trend.Offspring living in EPA,the R0,T were have significant different(P<0.05)with control from 0.5 to 10?g/L,whether offspring living in what enviroment,not have significant different with each other(P>0.05). |
PDF Full Text Request