The Research Of Change Of Population Structure Of Artemia Parthenogenetica And Taxonomic Status Of Bisexual Artemia, In The Four Coastal Salterns Of Liaoning Province, China

The brine shrimp Artemia is widely distributed in saline inland lakes and coastal salterns and it is a occupying species.It belongs to Arthropoda, Crustasea, Branchiopoda, Anostacea, Artemidae and Artemia. The parthenogenetic species is distributed in coastal salterns, whereas the bisexual species is distributed in saline inland lakes popularly. Before the 1990s, there was only one parthenogenetic species and male individual was rare( 2‰～6‰) in the four coastal salterns of Liaoning Province, but a mass of male individual had been found after 2001. The gender ratio was about 1:1 by the ecology investigation in the four coastal salterns of Jinzhou, Pulandian, Wafangdian in Dalian and in Yingkou, Liaoning Province in 2005. The results obtained showed that the exotic bisexual species had invaded four coastal salterns of Liaoning Province.The initial findings revealed that the exotic bisexual species might be Artemia.franciscana, by analyzing of the color of cysts, the diameter of cysts and the weight of the cysts of different Artemia populations. The morPHology of frontal knobs of male individual of four coastal salterns in Liaoning Province was examined and a comparison was made with Artemia.franciscana, Artemia.salina.The morPHology of frontal knobs of four coastal salterns in Liaoning Province was similar to Artemia.franciscana, by analyzing of shape, measure values of frontal knobs and the number, distribution of knob spines. Therefore, we estimated the exotic bisexual species was Artemia.franciscana in four coastal salterns in Liaoning Province. The genetic structure of six different populations of Artemia was investigated by Inter-Simple Sequence Repeats (ISSR) marker of 60 individual. Of the 171 ISSR loci tested, 150 loci were polymorPHic and the total percentage of polymorPHic loci was 87.72%. We found a clear tendency for lower Fst values and higher gene flow levels between Artemia populations of four coastal salterns in Liaoning Province and Artemia.franciscana, whereas for higher Fst values and lower gene flow levels with Artemia.salina. The result indicated that Artemia. franciscana had invaded Artemia populations of four coastal salterns in Liaoning Province. Six brine shrimp Artemia populations can be divided two subgroups: Jinzhou , Pulandian , Yingkou , Artemia. franciscan, Wafangdian and Artemia.salina based on the Popgene1.32 and Arlequin3.01 neighbor-joining(NJ) dendrograms of Nei's genetic distance. Consequently we ensure that the exotic bisexual species is Artemia.franciscana in four coastal salterns of Liaoning Province.