Species Diversity Of Larvae Fish In Mangrove Of Leizhou Peninsula And The Response Of Oryzias Curvinotus To Nonylphenol

Leizhou Peninsula is located in the southernmost tip of China,is China's third largest peninsula,with China's most abundant mangrove resources.Staggered mangroves produce abundant fish resources and have high biodiversity.In view of the increasingly serious environmental problems,this subject has investigated the fish in the early development stage of the Leizhou Peninsula mangrove area in the current environment.We collected1683 individuals that contain 57 species of larvae and juveniles fish in Gaoqiao National Mangrove Reserve,Hongshidi Mangrove of Xialiu town,Beijia village of Fucheng town and Jiulongshan National Mangrove Wetland Park from April 2014 to June 2016.The phylogenetic analysis of 22 species of Gobiidae was carried out,and the population differentiation of Gobiopterus lacustris in the mangrove area of East and West of Leizhou Peninsula was described.And then qualitative analysis of environmental estrogen in 8sample sites of Gaoqiao National Mangrove Reserve,Rare Animal Protection Area of Beihe town,Liusha Bay,the Southwest Side of Haiwan Bridge,Guanhai Promenade Artificial Mangrove Area,Donghai Island Mangrove Area,Beijia Village Mangrove Area of Fucheng town,Jiulongshan Mangrove National Wetland Parkin of Leizhou Peninsula.A high-throughput sequencing of transcriptome for Oryzias curvinotus was carried out and the Chg H,Chg L,ESR1 genes were validated.And its expression in the endocrine disrupting nonylphenol exposure was analyzed.The results of this study are summarized as follows:1.A total of 57 species of larvae or juveniles were identified by DNA barcode technique,and 78.57% were Perciformes,while Gobioidei accounted for 61,7% of Perciformes.Among them,the dominant species include Gobiopterus lacustris,Sicyopterus pugnans,Pseudogobius masago,Mugilogobius abei,Oryzias curvinotus,Ambassis marianus and so on.In the spring(February to April),the number of species was the highest(45 species),and the number of species(14 species)was the lowest in autumn(August to October).The number of species in Xialiu was the largest(37 species)in the four sites,while Gaoqiao had the least number of species(23 species).The fish ecologygroup is dominated by marine migratory fish.2.There were 88 COI sequences of 22 species of Gobioidei,and the number of conserved sites was 311,the number of variable sites was 217,the number of parsim-imfomative sites was 207,and the singleton sites were 10.The frequencies of four base distributions of T,C,A and G were 30.3%,28.2%,23.4% and 18.1%,respectively,where the base T was biased to the second locus(43%)of the codon.There were 58 haplotypes in 88 sequences of 22 species of Gobiidae,and the haplotype diversity was0.984 ± 0.005.The genetic relationships between Oligolepis sp and Sicydium sp were the closest,and the interspecific genetic distance was 0.004.Acentrogobius pflaumii had the closest genetic relationship with the Oxiderces dentatus,and the genetic distance was0.277.3.The genetic diversity of Fucheng population was the highest,while the Jiulongshan population was the lowest from five populations of Gaoqiao,Xialiu,Donghai Island,Fucheng and Jiulongshan.There are significant genetic differentiation between the three groups on the east coast of Leizhou Peninsula and the two groups in the West Bank,and the gene flow between the east and the west bank is weak.Molecular variance analysis(AMOVA)revealed that genetic variation was mainly derived from the population.4.The results showed that there were environmental estrogenic contamination in the mangrove area of east Liusha Village of Liusha town,and there were substances that enhanced estrogenic activity in most of the sample sites.5.Illumina High-throughput sequencing results showed that the female Hainan medaka obtained Clean reads 80095044,while male Hainan medaka won 87043984.And the base error rate was 0.02%.Differences in expression analysis showed that there were26588 genes in female and male medaka,but only 14285 genes were expressed in male individuals,and 3111 genes were expressed only in female individuals.The relative expression level of Chg H,Chg L and ESR1 gene in female and male medaka was consistent with that of transcriptome,and the expression of ESR2 in female medaka was2.70 times that of male.6.We selected the laboratory breeding 90 days of the same status of the Hainan medaka F1 male,male individuals,the use of 10 nM,100nM,1000 nM nonylphenol(NP)exposure treatment for 5d.In the 10 nM nonylphenol exposure treatment group,the expression of Chg H(P <0.01),Chg L(P <0.05)and ESR2(P <0.01)of male were significantly down-regulated,while the ESR1 of male was also down-regulated with no significant.In female,the expression of Chg H(P> 0.05),Chg L(P> 0.05)and ESR1(P>0.05)were also down-regulated compared with the control group,and ERS2(P> 0.05)wasup-regulated,but there was no significant difference.In the 100 nM nonylphenol exposure treatment group,the relative expression of four estrogen-related genes in male and female medaka was up-regulated on the basis of 10 nM,among them,Chg H(P <0.05)and ESR2(P <0.01)were significantly up-regulated in female,the expression of Chg L(P <0.05),ESR1(P <0.01)and ESR2(P <0.01)were up-regulated.At 1000 nM,the ESR1(P <0.05)and ESR2(P <0.01)genes were significantly down-regulated.In a word,the Chg L gene was more sensitive to nonylphenol in the liver of Hainan medaka,and the expression level of 100 nM nonylphenol was the highest.