Thoracica、Brachyura (Thecostraca) DNA Barcoding Analyses

Taxonomy develop relatively slow that is the base of biology research all thetime.Before the 1980s.It is mainly based on the morphological characteristicsof species.but the convergent evolution.divergent evolution larval form difficultto capture.natural factors et al leading to the shape of the standard hard todescribe species.After 80s.with the rapid development of moleculartaxonomy.DNA classification was born. More than ten years.All areas ofscholars explore DNA classification.and achieved gratifying achievements.Theclassification threshold value of Heter is widely spread.means intraspecificdistance is less than 2%，interspecific distance is more than 10%.Crustaceanshave high diversity，including in particular very many economic of animals,suchas shrimp crab,etc;and include some dirty animals.such as barnacle.Throughthis paper studies to the crustaceans classification system to be moreperfect.not only give some areas and personnel to bring more economicbenefit.but also provides the data support for crustaceans DNA barcodedatabase.This paper collectedspecimens89,including48barnacle,41 crab，withMr Ren’s identifying,All the specimens have saved China academy of sciencesherbarium Marine research institute.This paper mainly work is divided into twoparts:(1)Barnacle is belongs to Thoracica of Crustaceea.in Crustaceea Systemdevelopment,it is the lowest,Because they live in intertidal zone，the appearance is strange,once thought to be double shell,morphology Betweenspecies are ofen not identifiable because of the scour.The paper determinedthree mitochondrial gene fragments and compared different gene fragments(COI,16S,12S,28S and 18S)feasibility and effectiveness as barcoding to identifyBarnacle species,joint 12S,16S gene sequence and Preliminary analysisPhylogenetic of the Balanidae.The results show that:the COI distance betweengroups and distance within groups have obviously interval,Minimum distancebetween species is0.122,being much larger than the maximum distance withinspecies(0.023).The distance between groups and distance within groups of 16Shave coincidence,minimum distance between specie 0.018 less than themaximum distance within species 0.023,Therefore,the mitochondrial COI genecan more accurately identify barnacle between species and within species,andintraspecific differences is reached less than 0.023,differences betweenspecies is greater than 0.1.Phylogenetic analysis of ML and BI was consistentand support the four subfamily system. Megabalaninae form a monophyleticwith a higher rate of support,and prove that transverse tubes isplesiomorphy.Amphibalanus and Fistulobalanus forming a single clade.Theresult support Newman & Ross (1976) hypothesis that the two should bemerged.(2)Brachyura is The highest species of crab that belongs to Brachyura ofCrustacea,its live in intertidal zone,has a very high diversity,because ofConvergent evolution of species,System development is still not clear,andclassified work based on the morphological characteristics is still verydifficult.this paper uses the DNA Molecular markers,determined the Part ofgene sequence of mitochondrial COI from the representative of Crab of 5superfamilies had determined,the relationships between every family of crabwas preliminary analysised,the results indicate:The BI,NJ MP have Basicconsistent results that 5 surper Familys have consistently Topological structurewith the current system of classification of morphological classificationsystem.In addition to several individual species,the minimumin geneticdistance between species of crab is 10.1%,more than 10%,the maximum within species of crab is 1.2%,less than 2%,and have an obvious barcoding gap,andshow that Threshold of DNA barcoding classification of Hebert also apply toCrab.Eucrate tripunctata Campbell is a new cryptic species,with high approvalrating The specimens from province hai nan and the one from guang xi gatheredin one,and the other four from guang xi specimens gathered for in one,thegenetic differences between the branchs as high as 8.9%,and the geneticdifferences of sisters species each of the branch only 0,so Eucrate tripunctataCampbell is a new cryptic species,this paper show that the the genetic distancebetween Perisesarma_bidens and the species of Grapsidae Is 0.133,less thanthe 0.2with species of Ocypodidae,Perisesarma bidens have More recentpaternitywith Grapsidae than Ocypodidae,So this paper take Perisesarmabidens to belong to Grapsidae;BI and NJ display that Paracleistostomacrassipilum with the species of Grapsidae Get together one,the average geneticdistance between Paracleistostoma crassipilum and species of Grapsidae isless than species of Ocypodidae,so this paperTake it to Grapsidae.Withconfidence 0.80,Mixtyris brevidactylus and species of Grapsidae get togetherone in BI,the genetic differences between Genus Mixtyris and Grapsidae issimilar to the differences between Genus Mixtyris and Ocypodidae.Only BIsupport that Genus Mixtyris belong to Grapsidae in three trees,the other displaythat Genus Mixtyris is a monophyly,Only a large amount of expandingspecimens can be completely clear demonstration experiment Genus Mixtyriswhat should belongs to Grapsidae or Ocypodidae,at present this paper agreenthe idear of Guinot who Promoted it to superfamiliy,butalso Tied for in theGrapsidae and Ocypodidae.