Study On The Assocation Of Adult And Larval Stage Of Chironomid (Diptera:Chironomidae) And Its Effect On Water Quality Evaluation

The Chironomidae insect is one of the main groups in the freshwater ecosystem.The insects live in various water environments and are rich in species and quantity.They are distributed in all continents of the world,including the Antarctic continent.However,due to the long life history of chironomids and the uncoordinated classification system,the phenomenon of the same pecies with different names in chironomid serious,which cause great troubles in the application of chironomids on aquatic products,environment and ecology.In order to solve the problem of accurate identification in chironomid taxonomy,in this study,the matching relationship between adults,larvae and pupa was established by cultivating egg collection and collecting larvae.In order to accurately identify chironomids,the mitochondrial gene cytochrome coxidase subunit 1(COI)was selected as a molecular marker by molecular biological means and combined with the morphological classification characteristics.We paired a total of 11 species of chironomid,belonging to and 3 subfamilies,including 9 species for egg collection,1 specie for larval culture,and 1 specie for capture.This study first described the larval and pupa characteristics of Hydrobaenus dentistylus in the world and Chironomus tainanus in China,and found a new species of the genus Paratanytarsus.A total of 42 sequences from 10 species were obtained and uploaded to BOLD.Combining the COI data in BOLD and Genbank,a total of 486 homologous sequences with a similarity of more than 90% were obtained.The genetic distances between the species and the species of the chironomids were calculated by constructing neighbor-joining trees,and the indistinguishing chironomids in the current morphological classification were further described based on DNA data.Based on the data from public library,eight misidentification are found and determined four sequences.In the data Genbank,Chironomus flaviplumus(JF412075-JF412077)uploded by Kim,S et al.(2012)should be Chironomus yoshimatsui.Kieffulus barbatitarsis(KP902779-KP902780、KP902780)uploded by Chen,J et al.(2015)should be Kieffulus tainanus.Chironomus sulfurosus(AB704937)and Chironomus sulfurosus(KT212998)from GenBank uploded by Cornette,R et al.(2012)and Pramual,P.et al.(2016)should be Glyptotendipes tokunagai.Propsilocerus sp.(KP902817-KP902820)uploded by Hen,J et al.(2015)should be Propsilocerus taihuensis.Through sequence analysis,the maximum genetic distance of Glyptotendipes tokunagai between uploaded from this study and the same name sequence from other regions of the world reached 9.9%.And the maximum genetic distance of Polypedilum cultellatum between uploaded from this study and the same name sequence from other regions of the world reached 18.1%.Therefore,there may be cryptic species between the two species.In order to explore the application of chironomid larvae in water environment monitoring and ecological evaluation,stream in Xianju National Park were surveyed to explore the community structure of chironomid larvae and their indicative significance of the water quality.86 species of chironomid larvae belonged to 51 genera and 4 subfamilies were identified.Conchapelopia sp.was the overwhelming dominant species and Polypedilum flavum,Rheocricotopus sp.,Cricotupus vierriensis,Rheotanytarsus muscicola and Corynoneura carriana were the dominant species of Chironomid larvae in the streams of Xianju National Park.The result of indicator species analysis showed that Cricotupus vierriensis,Nanocladius dichromus,Tanytarsus formosanus,Tanytarsus mendex were indicator species of moderated pollution water,and Rheocricotopus sp.was the indicator species of clean state water.