The present investigation focuses on population structure analysis of the purple sea urchin Paracentrotus lividus across the African Mediterranean coast, with the main aim of assessing the influence of the Siculo-Tuni...The present investigation focuses on population structure analysis of the purple sea urchin Paracentrotus lividus across the African Mediterranean coast, with the main aim of assessing the influence of the Siculo-Tunisian Strait on gene flow disruption in this highly dispersive echinoid species. For this purpose, patterns of morphological and genetic variation were assessed among its populations from the western and eastern Mediterranean coasts. A total of 302 specimens from seven Tunisian sites were collected and examined for morphometric variability at twelve morphometric traits. Concordant results, inferred from CDA（canonical discriminant analyses）, pairwise NPMANOVA（non parametric multivariate analysis of variance） comparisons and MDS（multidimensional scaling） plot, unveiled significant inter-population differences in the measured traits among the studied populations. Furthermore, the combined use of the one way ANOSIM（analysis of similarities） and the Discriminant/Hotelling analysis allowed unravelling two morphologically differentiated groups assigned to both western and eastern Mediterranean basins. The SIMPER（similarity percentages） routine analysis showed that total dry weight, test diameter and spine length were major contributors to the morphometric separation between locations and between groups. Pattern of phenotypic divergence discerned in P. lividus across the Siculo-Tunisian Strait is interestingly in congruence with that inferred from the genetic investigation of the purple sea urchin populations from the same region based on the analysis of the mt DNA COI（cytochrome oxidase I） gene in 314 specimens from nineteen locations covering a wider geographic transect, streching westward to the Algerian coast and eastward to the Libyan littoral. The specific haplotypic composition characterizing each Mediterranean basin,as inferred from the minimum spanning network, confirmed the geographic partioning of genetic variation, as revealed by F-statistics and AMOVA（analysis of molecular variance） analyses, yielding significant genetic differentiation between eastern and western Mediterranean populations. The newly detected phylogeographic patterns, observed for the first time in P. lividus throughout the explored distribution range, suggest the involvement of different biotic and abiotic processes in shaping such variation, and provide evidence that a large and geographically exhaustive dataset is necessary to unveil phylogeographic structure within widespread marine species, previously cathegorized as panmictic in part of their distribution range.展开更多
Objective:The overexploitation of the sea urchin Paracentrotus lividus stock,as a consequence of the growing market demand for roe,has boosted the research for echinoderm rearing.The chemical,physical,and microbiologi...Objective:The overexploitation of the sea urchin Paracentrotus lividus stock,as a consequence of the growing market demand for roe,has boosted the research for echinoderm rearing.The chemical,physical,and microbiological characteristics of land-based facilities are crucial for sea urchins’health and human consumption of their products.In Italy,health-hygienic regulations for P.lividus rearing are still to be perfected by the authorities.In this context,we characterized the microbiological quality of a pilot land-based facility for sea urchin production at the University of Cagliari(Italy)to support the development of technical production regulations.Materials and Methods:The accredited Hygiene Laboratory of Cagliari University collected and analyzed the samples in June 2023.Mesophilic bacteria,yeasts,and molds were searched for in air and on surfaces.Total coliforms and Escherichia coli,Enterococci,Pseudomonadaceae,Staphylococcus aureus,sulfite-reducing Clostridia,and Vibrio spp.were identified in water samples.We searched forVibrio spp.and Pseudomonas spp.in the gonads and coelomic fluid of sea urchins.Results:Although air,surfaces,and water quality were satisfactory overall,some critical points should be monitored more strictly.Enterococci concentration was 250 CFU/100 mL in the water reserve,suggesting animal contamination(other than humans).Pseudomonas aeruginosa was the most resistant to filtration processes,with a residual concentration of 6 CFU/250 mL after the second filtration.No colonies of Vibrio spp.or Pseudomonas spp.were isolated in sea urchins’gonads or coelomic fluid.Conclusions:Starting from the results,we provided targeted advice for developing technical production regulations,system monitoring,and facility routine maintenance in accordance with the‘best practice’approach.This analysis could be considered a first step toward the elaboration of common regulations about the minimal standards for the breeding environment of P.lividus by national and regional authorities.展开更多
文摘The present investigation focuses on population structure analysis of the purple sea urchin Paracentrotus lividus across the African Mediterranean coast, with the main aim of assessing the influence of the Siculo-Tunisian Strait on gene flow disruption in this highly dispersive echinoid species. For this purpose, patterns of morphological and genetic variation were assessed among its populations from the western and eastern Mediterranean coasts. A total of 302 specimens from seven Tunisian sites were collected and examined for morphometric variability at twelve morphometric traits. Concordant results, inferred from CDA（canonical discriminant analyses）, pairwise NPMANOVA（non parametric multivariate analysis of variance） comparisons and MDS（multidimensional scaling） plot, unveiled significant inter-population differences in the measured traits among the studied populations. Furthermore, the combined use of the one way ANOSIM（analysis of similarities） and the Discriminant/Hotelling analysis allowed unravelling two morphologically differentiated groups assigned to both western and eastern Mediterranean basins. The SIMPER（similarity percentages） routine analysis showed that total dry weight, test diameter and spine length were major contributors to the morphometric separation between locations and between groups. Pattern of phenotypic divergence discerned in P. lividus across the Siculo-Tunisian Strait is interestingly in congruence with that inferred from the genetic investigation of the purple sea urchin populations from the same region based on the analysis of the mt DNA COI（cytochrome oxidase I） gene in 314 specimens from nineteen locations covering a wider geographic transect, streching westward to the Algerian coast and eastward to the Libyan littoral. The specific haplotypic composition characterizing each Mediterranean basin,as inferred from the minimum spanning network, confirmed the geographic partioning of genetic variation, as revealed by F-statistics and AMOVA（analysis of molecular variance） analyses, yielding significant genetic differentiation between eastern and western Mediterranean populations. The newly detected phylogeographic patterns, observed for the first time in P. lividus throughout the explored distribution range, suggest the involvement of different biotic and abiotic processes in shaping such variation, and provide evidence that a large and geographically exhaustive dataset is necessary to unveil phylogeographic structure within widespread marine species, previously cathegorized as panmictic in part of their distribution range.
基金funded by National Recovery and Resilience Plan(NRRP),mission 4 Component 2 Investment 1.5,Project name:eINS Ecosystem of Innovation for Next Generation Sardinia(No.ECS0000038-CUP F53C22000430001),Italy.
文摘Objective:The overexploitation of the sea urchin Paracentrotus lividus stock,as a consequence of the growing market demand for roe,has boosted the research for echinoderm rearing.The chemical,physical,and microbiological characteristics of land-based facilities are crucial for sea urchins’health and human consumption of their products.In Italy,health-hygienic regulations for P.lividus rearing are still to be perfected by the authorities.In this context,we characterized the microbiological quality of a pilot land-based facility for sea urchin production at the University of Cagliari(Italy)to support the development of technical production regulations.Materials and Methods:The accredited Hygiene Laboratory of Cagliari University collected and analyzed the samples in June 2023.Mesophilic bacteria,yeasts,and molds were searched for in air and on surfaces.Total coliforms and Escherichia coli,Enterococci,Pseudomonadaceae,Staphylococcus aureus,sulfite-reducing Clostridia,and Vibrio spp.were identified in water samples.We searched forVibrio spp.and Pseudomonas spp.in the gonads and coelomic fluid of sea urchins.Results:Although air,surfaces,and water quality were satisfactory overall,some critical points should be monitored more strictly.Enterococci concentration was 250 CFU/100 mL in the water reserve,suggesting animal contamination(other than humans).Pseudomonas aeruginosa was the most resistant to filtration processes,with a residual concentration of 6 CFU/250 mL after the second filtration.No colonies of Vibrio spp.or Pseudomonas spp.were isolated in sea urchins’gonads or coelomic fluid.Conclusions:Starting from the results,we provided targeted advice for developing technical production regulations,system monitoring,and facility routine maintenance in accordance with the‘best practice’approach.This analysis could be considered a first step toward the elaboration of common regulations about the minimal standards for the breeding environment of P.lividus by national and regional authorities.
