Study Of Community Structure Characteristics Of Metazoan Zooplankton In Qingcaosha Reservoir,Shanghai

Now,the Qingcaosha Reservoir is the largest source of drinking water in Shanghai.It is located in northwest Changxing Island in the Yangtze River and across the river with the Chongming Island.Special geographical location of Qingcaosha Reservoir.It is led by the leaders because it provides a large number of high-quality drinking water for the citizens.The metazoan zooplankton play an important role in the ecological structure of the biological community.Study of the characteristics of the community structure of the metazoan zooplankton to Shanghai's largest source of the Yangtze River estuary river reservoir--the Qingcaosha Reservoir,from January 2014 to December 2015.We were studied the species composition,dominant species,quantitative distribution and community characteristics of rotifer.To provide important scientific evidence for the protection and management of the water source area that it is to provide the important status of the survival and the analysis of the data for the prevention and monitoring of the water quality of the reservoir.The results:1.A total of 58 species of zooplankton were identified in the two year sampling of the reservoir.It is belongs to 23 families and 37 genera.In 2014 identified 39 species,identified in 2015 48.In the metazoan zooplankton in the Qingcaosha Reservoir,In 2014,the percentage of total density of rotifers,copepods and cladocera were 81.5%,7.2% and 11.3%,respectively,the percentages of biomass were 7.5%,55.2% and 37.3%,respectively.In 2015,the percentage of total biomass density of rotifers,copepods and cladocera were 98.7%,0.7% and 0.6%,respectively,the percentages of biomass were 37.1%,50.6% and 12.3%,respectively.The biomass was high because of the large and wet individuals,the biological density was not high yet.2.In this experimental study,there were totals of 32 species of rotifers were identified in two years.In 2014,there were about 20 species in the year of,and in the year of 2015,there were two species,in 2014 and 2015,there were identified,20 species and 26 species respectively.The dominant species have Brachionus angularis?Keratella cochleari?Polyarthra trigla?Polyarthra euryptera etc in two years.There were 8 kinds of oligo species.In 2014 annual biological density was lower than in 2015,that is 156.4±119.5ind/L and 237.1±252.9 ind/L,respectively.In 2014 annual biomass was higher than in 2015,that is 0.132±0.115mg/L and 0.123±0.137 mg/L,respectively.Redundancy analysis shows that water temperature,dissolved oxygen,total nitrogen and total phosphorus were the main influencing factors,between the biomass of planktonic algae and the density of rotifers a positive correlation.3.There were 12 species of copepods be identified in two years,that is belonging to the 9 genera of 5 families.The dominant species have Sinocalanus dorrii ?Limnoithona sinensis?Eucyclops serrulatus?Mesocyclops leuckarti etc in two years.In 2014 annual biological density was higher than in 2015,that is 13.82±20.38ind/L and 1.60±1.55ind/L,respectively.In 2014 annual biomass was higher than in 2015,that is 0.97±1.52mg/L and 0.17±0.21mg/L,respectively.Redundancy analysis shows that the main influencing factors have water temperature,permanganate index,total phosphorus,phytoplankton density for the copepods density.4.There were 14 species of cladocera be identified in two years,that is belonging to the 9 genera of 6 families.The dominant species of cladocera have Ceriodaphnia cornuta ? Bosmina longirostris ? Bosminacoregoni ? Bosmina fatalis ? Moina rectirostris?Moina macrocopa etc in two years.In 2014 annual biological density was higher than in 2015,that is 21.59±39.80ind/L and 1.54±1.94ind/L,respectively.In 2014 annual biomass was higher than in 2015,that is 0.67±1.21mg/L and 0.04±0.06mg/L,respectively.Redundancy analysis shows that the main influencing factors have water temperature,transparency,conductivity,permanganate index for the cladocera density.The total species similarity of the zooplankton in Qingcaosha Reservoir:Very similar in upstream and middlestream(Sj=0.86),very similar in the middlestream and downstream(Sj=0.78),upstream and downstream are not similar(Sj=0.67)reaches of the 2014,upstream and middlestream are not similar(Sj=0.66),upstream and downstream are not similar(Sj=0.71),Very similar in middlestream and downstream(Sj=0.83)reaches of the 2015.The total storage capacity of metazoan zooplankton.Annual biological density: 2014(190.66±124.86ind/L)<2015(240.25±248.60ind/L),annual biomass: 2015(0.33±0.16mg/L)<2014(1.74±2.19mg/L).In 2014 average annual density was less than in 2015,and the average annual biomass was more than 2014 in 2015,the main reason is that Copepods and Cladocera were higher in 2014 than in 2015,Copepods and Cladocera are large in size,The individual wet weight were much larger than that of the Rotifers,rotifer biomass was highest in 2015,the average annual biomass of the zooplankton was lower than that of 2014 due to small in size and small in wet weight for Rotifers.In 2015,the average annual biomass of zooplankton was lower than that in the year of 2014.In two years,the biomass of zooplankton showed a high trend in summer and autumn and low in winter and spring,this trend of biomass the same as density.From upstream to downstream water flow increasingly slowly,according to the similarity of species,the middle and lower reaches of the similarity increased,it shows that the ecological structure of the metazoan zooplankton is increasingly stable.