Invertatebrate Resting Egg Banks In Coastal Wetland Sediments Of Jiangsu And Zhejiang

Dormancy is a survival strategy of many invertebrate in response to adverse environmental conditions and producing resting egg is one of the most universal form of dormancy.Many aquatic invertebrate resting eggs can survive more than 1 year,in that case,the resting eggs can accumulate and form egg bank in the sediments.Dormancy eggs play an important role in maintaining biodiversity of aquatic invertebrate conmmunity,abundance of species,evolution and ecological restoration.Wetland is an transition biosystem of land and ocean,as reclamation engineering,port construction and other exploration of coastal area,which have a great influence to the coastal wetland,and then the change of coastal wetland environment can induce biodiversity and abundance change of aquatic invertebrate and cause the production of resting eggs.So the community structure of egg bank in the sediments can reflect the change of conditions of the aquatic environment.Meanwhile,the research on the conmmunty structure of egg bank can help to illustrate the process of potencial recruitment of resting eggs to the active population in waters,which bring more comprehensively understandings about aquatic invertebrate living in coastal wetland of Jiangsu and Zhejiang.Besides,the CO I sequences and morphological pictures of resting eggs achived in this passage will provide reliable instrumental study material to the research of egg banks.This study focused on Jiangsu and Zhejiang coastal area aquatic habitats including rivers,ponds and offshore sea area,and used the DNA Barcoding to identify the resting eggs combining with morphological pictures of resting eggs,and provided the identification handbook of resting eggs.The egg bank conmmunity structure information about different habitats seddimets achived in this study as follows:(1)This research used the cup mud sampler and grab type samper to collect the sedments of coastal wetlands from Yangshan Hand of Lianyungang(about N 34°42')in north of Jiangsu to Cangnan country(about N 27°30')in south end of Zhejiang.And the wetland habitats were consist of coastal ponds(31 samples),coastal river(29 samples)and offshore sea area(15 samples).And this passage measured 6 environmental parameters:water sample pH,sediments pH,ORP of sediments,Organic content of sediments,Mud content of sediments.And these environmental parameters did not have significant correculations with abundance of resting eggs.(2)In this research,I collected over 6000 pictures of resting eggs and over 1300 sequences of CO.In the Jiangsu and Zhejiang coastal wetland sediments I identified 112 kinds of invertebrates resting eggs,including cladocerans 32 species;29 kinds of rotifers mainly belonging to Brachionidae;and 20 kinds of copepods from Centropagidae,Pontellidae and Acartiidae in marine species,and Diaptomidae and Sinocalanus tenellus in freshwater spiecies,and 31 other spicies which were from Arthropoda,Mollusca and Bryozoa etc.(3)There were significant difference between different ponds sediment in Jiangsu and Zhejiang coastal area both in species diversity and in abundance of resting egg banks.All sampling points species number ranged in 6?35,dominant species mainly including Brachionidae,Cyprididae,Tanytarsus formosanus,Plumatella,and Moina.Brachionidae species were dominant species both in Jiangsu and Zhejiang coastal ponds sediment,and Bryozoa species were the dominant species only in Zhejiang.(4)The number of species and abundance of resting eggs in rivers were lower than those in coastal ponds,and in the rivers the dominant species are Brachionidae and Monia.Brachionidae species were often regard as indicator species for eutrophication,and Moina species often became dominant species in polluted water,so they can reveal the rivers are eutrophicated or polluted in some degree.(5)In the offshore sea samples,both the number of spiecies and the abundance of resting eggs were at a low level,Labidocera rotunda was the dominant species in most sampling stations.And through comparing with the research in community of active populations in yellow sea and east sea,I found the resting eggs of Pareucalanus attenuatus as a new species living there,indicating the distribution of this species in the research area.And other resting eggs species were similar with the active populations.(6)This study focused on three types of habitats to investigate the ivertebrate resting egg banks community structure on a large scale,but I did not find significant correlaions between the latitude and abundance of resting egg or Shannon-Weaver index.About resting eggs from three habitats wetland in Jiangsu and Zhejiang supplied the knowledge about aquatic invertebrate community of this area and obtained CO I sequences and morphological pictures of resting eggs,which would provided the fundermental material to the study of invertebrate community or coastal construction's influence on coastal wetland in the future.And the results on the relationships between abundance of resting eggs,Shannon-Weaver index and pH of water samples,pH of sediments,ORP of sediments,Organic content of sediments,Mud content of sediments respectively,offered the foundation for the research of relationships between environmental conditions and resting eggs.The present study also explored the relationship between the abundance and diversity of egg banks and latitude on a large scale,which had some implications on large-scale pattern to egg banks.