Research On The Diversity Of Fish Classification And Genetic Diversity Of Dominant Species In Dongping Lake

It is imperative to address the issue of declining natural fish populations in Dongping Lake,which is the second largest freshwater lake in Shandong Province.Due to the rapid development of industrial and agricultural economies,as well as water conservancy construction,natural populations of freshwater fish in Dongping Lake have decreased,resulting in a decline in the quantity and quality of natural fish fry and varying degrees of deterioration of fishery resources.It is crucial to promote sustainable development of fishery resources.Therefore,conducting a comprehensive investigation of the fish resources in the waters of Dongping Lake,understanding the resource status of the fish,using the classification diversity index and G-F diversity measurement index to study the composition and classification diversity of fish germplasm resources,as well as conducting genetic diversity research on the important economic advantage species of Pelteobagrus fulvidraco in the waters of Dongping Lake,will help promote the protection of fish germplasm resources in Dongping Lake,Furthermore,provide technical support for relevant departments to develop strategies for protecting fish resources in Dongping Lake.Based on the fish resource survey data from 1979 to 1980 and the fish survey data from 2020 to 2022,analyze its species composition and calculate its taxonomic diversity index and G-F diversity index.The results showed that 55 species of fish belonging to 44 genera,15 families,8 orders were recorded in 1979-1980,and 41 species of fish belonging to 39 genera,15 families,7 orders were recorded in2020-2022,of which Cypriniformes was absolute advantage;Average Classification Difference Index of Fish in Dongping Lake from 1979 to 1980 and from 2020 to 2022(Δ+)They were 71.19 and 79.39,respectively,with a classification difference variation index(Λ+)of 581.9 and 561.5,a family diversity index(F-index)of 5.05 and 4.15,a genus diversity index(G-index)of 3.70 and 3.65,and a standardized G-F index of 0.27 and 0.12.The diversity changes at the family,genus,and species levels of fish in Dongping Lake were analyzed using the classification diversity index and G-F diversity index.The results showed that from the late 1970 s to the early 2020 s,the number of fish species in Dongping Lake significantly decreased due to regional environmental changes and human activities,and the diversity of fish species showed a downward trend.The fish community structure was relatively fragile and vulnerable to interference and destruction.It is recommended to protect and restore the water environment and fish habitats of Dongping Lake,construct fish migration channels,and promote the effective restoration of fish germplasm resources in the lake area.Pelteobagrus fulvidraco is an important economic fish species in Dongping Lake.To analyze and compare the genetic diversity of yellow catfish,wild yellow catfish from Dongping Lake,Dong’a section of the lower Yellow River,and Weishan Lake were collected.The mitochondrial D-loop gene was used to analyze the genetic diversity and structure of three different geographical populations.The results showed that the D-loop region alignment length of yellow catfish included 927 loci,with 167 base deletions,33 polymorphic loci,857 conserved loci,16 haplotype polymorphic loci,17 concise information loci,45 haplotypes,0.877 haplotypes,and a polymorphism factor k of 3.25 for haplotypes.The average haplotype diversity index(H)was 0.877 ± 0.025,the nucleotide diversity index(π)was 0.00369 ± 0.00053,and the overall genetic differentiation index(Fst)was 0.0783(P<0.01).The results showed that the Genetic distance between Weishan Lake population and the other two populations was larger,the Genetic distance between Dongping Lake population and Dong’e section population in the lower reaches of the Yellow River was smaller,Weishan Lake belonged to the Huai River system,Dongping Lake and Dong’e section in the lower reaches of the Yellow River belonged to the Yellow River system,indicating that Weishan population had less genetic exchanges with Dongping and Dong’e populations,while gene exchanges between populations in similar waters were more frequent.The gene flow coefficient Nm between Dongping and Dong’eduan populations obtained in this study is 2.73,indicating that there is a certain gene flow between populations.Through the analysis of the genetic difference index and Genetic distance of Pelteobagrus fulvidraco in different waters,as well as the analysis of the gene flow coefficient between them,it shows that there may be a greater degree of gene exchange between the Dongping Lake Yellow River East Pelteobagrus fulvidraco populations in the Yellow River basin,and Pelteobagrus fulvidraco in the same basin often shows similar genetic characteristics,which can be regarded as a unified management unit.