Study On Morphology And Genetics Of Redlip Mullet (Liza Haematocheilus)

Liza haematocheilus, which belongs to Mugiliformes, Mugilidae, is an importanteconomical species distributed in coast waters along China, Japan and Korea.Seven meristic characters and thirty-three morphological characteristics weremeasured and the data was analyzed by the principle component analysis method,discriminatory analysis, one-way ANOVA and cluster analysis to study themorphological variations among five populations of L. haematocheilus (164individuals) collected from Yingkou, Dongying, Qingdao, Wenzhou and Guangzhou.The value of meristic counts presented a large degree of cross range among5populations. The result of principal component analysis indicated that nine principalcomponents were constructed by factor loading, the cumulative contribution ratio was79.6%. Scatter plots of scores on the first and second morphological characteristicsshowed that there was extensive overlap in five populations. The discriminantfunctions of five populations were established, and the total accuracy ofdiscrimination was83.5%. The multivariate analysis and one-way ANOVA resultsrevealed that there were significant differences (P <0.05) among populations in mostof morphological characteristics, also suggest that differences of morphologicalcharacteristics existed in L. haematocheilus populations. In the cluster analysis, fivepopulations were divided into two clades which were not consistent with thegeographic distribution, implied that environment factors effected more thangeographic isolation.Otoliths of161redlip mullets from5populations were compared based on ShapeIndex analysis and Fourier analysis. The results of multivariate statistics were similarto traditional morphology analysis. Certain degree of divergence among populationswas detected, which may be caused by the difference of environment in sea areas,such as temperature and salinity.To assess the role that Pleistocene ice ages have played in the evolutionaryhistory of the marine organisms and ecological connectivity among marine populations in the Northwestern Pacific, we analysed the intraspecificphylogeographic pattern and dispersal patterns in L. haematocheilus populations. Incontrol region analysis, a total of112samples were collected from six locations and56haplotypes were obtained. The pattern of distribution of genetic variability withhigh level of haplotype diversity and moderate nucleotide diversity was detected. Theminimum spanning tree constructed with56haplotypes showed three divergent clades,corresponding to those defined in the NJ tree which might be isolated and diverged indifferent marginal seas of the Northwestern Pacific during Pleistocene low sea levelstands. The population statistic FSTalso revealed significant genetic structure amongpopulations. The demographic history of L. haematocheilus was examined usingneutrality tests and mismatch distribution analysis which indicated a Pleistocenepopulation expansion. Meanwhile, similar results were found in Cyt b analysissupported our inference. The comparison results of Hakodate and Qingdaopopulations during different years demonstrated that marginally but significant (p <0.05) difference exited in two Qingdao populations but no significant difference (p>0.05) in Hakodate populations.The entire mitochondrial DNA control region sequence of L. haematocheilus wasamplified. The complete sequence is1085bp in length. The TAS and conservativesequence blocks (CSB-D,-E,-F and CSB1,2,3) in the D-loop were characterized andanalyzed.Determination of population genetic structure provides essential information toresource recovery. But till now, little research has been done on genetic structure orgenetic diversity for the redlip mullet. This research compared traditional morphologyand otolith’s morphology with mitochondrial DNA control region analysis and Cyt banalysis, provided further insight of L. haematocheilus`population structure. Theknowledge may be benefit to the fishery management of this species.