| In this study, phylogeographic patterns, genetic diversities, population structure, demographic history and population dynamics and historical evolution of Pampus argenteus, Pampus chinesis, Pampus minor, Pampus echinogaster, Pampus cinereious and Pampus punctatissimus in the Chinese coastal waters, Pakistan and Kuwait coastal waters were analyzed on the basis of mitochondrial DNA marker. The phylogeographic patterns, genetic diversities and population structures of the six marine fishes were carried out and the population dynamics of historical evolution were also reconstructed in the present studies.1) Morphometric measurements length-weight relationship and relative condition factor in silver pomfret, Pampus argenteus was sampled during July2010to November2011in Pakistan. In the samples standard length (SL) was ranged6.8-21.8cm and total weight9.4-450g was registered. In length-weigh relationship exponent b=3.51value indicated that the fish growth is positive allometric. The coefficient of determination R2=0.96values showed a strong correlation between the variables. The relative condition factor Kn were characterized in eight size classes. The mean condition factor(Kn) values range0.75-1.15, highest Kn was observed within the fishes which belongs to the size classes12.0-13.9cm whereas fishes in the size class of20.0-21.9cm possess lowest (0.75) Kn values. The t-test values were9.102(P<0.0001). Our findings shall pave a way for baseline information about an important fish species from the area and are similar to those reported from its distribution.2) The present study was aimed to examine genetic variation between Pampus argenteus and Pampus chinesis sampled periodically from2010to March2011in the coastal waters of Pakistan. Both of the species were identified using DNA barcoding technique. The estimated mean haplotype diversity and nucleotide diversity were0.67-0.98and0.002-0.014in P.argenteus whereas0.25-0.89and0.0015-0.0084in P.chinesis. Simultaneously we also used partial sequences of mtDNA control region (CR) and the cytochrome b (Cytb) to identify and determine the variation among both of the species. On the basis of the results achieved, from the results it is clearly shown that the intra-species variations subsequently less than that of inter-species and COI fragment of the mtDNA the most powerful sequence based approach used in identifying the fish species with the high level of accuracy.3) Genetic diversity and population structure of the Pampus echinogaster in Dongying, Qingdao, Zhoushan and Wenzhou and Nantong were investigated in this study.In total122sequences of the mitochondrial DNA control region fragment of P. echinogaster were used for this analysis and defined33haplotypes. Mean haplotype diversity and nucleotide diversity are0.791±0.037and0.004±0.0027respectively. Average nucleotide compositions showed high values of A+T base content (68.9%) as compare to G+C base content (31.1%). Percentage of variation among populations was0.23whereas within populations was calculated99.77%. AMOVA and conventional population FST showed no significant genetic differentiation throughout the sampling range (FST=0.00231). Neutrality tests and mismatch distribution analysis were used to examine demographic history of P. echinogaster, which indicated a late Pleistocene population expansion at about26,000-53,000years ago.4) Population genetic structure of Pampus argenteus from China, Kuwait and Pakistan waters was determined by using the mtDNA control region sequences analysis. High levels of haplotypic diversity (h=0.92±0.017, mean±standard deviation) and low nucleotide diversity (π=0.012±0.006) indicative that population bottleneck followed by quick population growth and increase of mutation The mismatch analysis shaped a unimodal distribution of pairwise differences consistent with the sudden population expansion model. This elucidation was also supported by the low levels of Harpending’s raggedness index and P values of SSD (Harpending,1994). The value of t was12.24, and the time since population expansion was estimated to be approximately132,000-264,000years before present (during the later Pleistocene) applied mutation rates mentioned above for the control region.5) Mitochondrial DNA control region of genus Pampus were amplified to study the structure of the studied Pampus species. mtDNA control region of the genus consisted of three domains, terminal associated sequence domain, the central conserved sequence domain and the conserved sequence block domain. The extended terminal associated sequences (ETAS), three central conserved sequence blocks CSB-F, CSB-E, CSB-D and three conserved sequence blocks CSB1, CSB2and CSB3, were identified into the conserved sequence block domain. Two TASs and two cTASs are detected in the species as well as CSB-F, CSB-E, CSB-D, CSB1, CSB2and CSB3. The results indicate that the structures of these parts are similar with most marine fishes. All the sequences of CSB1, CSB2and CSB3blocks are the consensus among different individuals, which is quite different from most vertebrates. In addition, COI and Cytb gene fragments are used to analyze the phylogenetic relationships of Pampus species. The phylogenetic trees show a lack of genetic structure among individuals.Six Pampus species, P. minor, P. echinogaster, P. chinensis, P. cinereus, P. argenteus and P. punctatissimus were identified. The genetic distance of intraspecies ranged from0.04to0.2, based on Cytb sequences data analysis. For COI sequence data analysis, the genetic distance of intraspecies ranged from0.01to0.16. Phylogenetic trees showed that all Pampus fishes reciprocally constituted a monophyletic group with strong support. According to the Pampus systematics of Liu et al.,(1999,2002) and results of Cui et al., (2009), the Pampus was divided into five species and, we strongly disagree with both of the scientists because our study confirmed that the Pampus fishes should be divided into six distinct species P. argenteus, P. chinesis, P. cinereous, P. minor, P. punctatissimus and P. echinogaster.6) We assessed some key management parameters of the Pampus argenteus such as maximum sustainable yield (MSY) based on the time series catch and effort data from1989to2009in Pakistan. Three surplus production models (SPMs) and three model error assumptions estimated by CEDA computer programme and two SPMs were estimated with ASPIC package. Estimated biological reference point (e.g. MSY) with ASPIC are Fox model5525mt and fishing mortality at maximum sustainable yield FMSY=1619, the coefficient of variation of estimated MSY was1.0and coefficient of determination R2=0.58and the catch ability coefficient q=0.00077were estimated. The logistic model out puts are MSY=94940mt and fishing mortality at maximum sustainable yield FMSY=6290, estimated CV (1.0) of the MSY and coefficient of determination R2=0.55. Three surplus production models of Schaefer, Fox and Pella-Tomlinson and model error assumption of normal, log normal and gamma were also estimated using CEDA package are Fox model MSY=3841(R2=0.63) and Schaefer and Pella-Tomlinson estimates were3800(R2=0.61) both the models produced similar MSY results. It seems that MSY estimated from the Schaefer and Pella-Tomlinson model were conservative than the Fox model which indicates a better fit. Moreover, values of coefficient of determination R2showed appropriation of the model. From the CEDA analysis some outliers were identified and these were in1986,2002and2009. On the basis of the outputs estimated with the ASPIC package appeared higher than the annual landings and seems non-conservative than the parameters estimated with CEDA software. In view of the estimations from CEDA package it seems that the stock are over fished and require some effective management and should maintain sustainable exploitation of the stocks by reducing fishing effort in the area and also implement conservation of an excellent food fish is required. |
PDF Full Text Request