| Sponges are the most ancient metazoa that live on microorganisms and small particles.They are also important pharmaceutical animals with promising application prospects.Variable internal mineralized and/or organic skeletons define the body shapes of sponges.To categorize sponges into taxonomic groups,parameters including spicule types,skeleton formations and sponge configurations are usually applied,which are highly variable among different sponges and thus render taxonomy studies even more complicated.As a result,taxonomists have made a lot of efforts in dealing with the difficulties.So far,the discovered marine and freshwater species have reached a total number of 8836.However,at least double more species have not been found.Among them,the vast majority of Hexactinellid(also known as glass sponge)species are deep-sea species which live on the hard or soft substrata at the depth of 200 m to 6000 m.As in the year of 2017,scientists have reconstructed the integrative systematic framework of glass sponges combining molecular and morphological methods.However,the taxonomic research in China works out slowly,in turn impeding the corresponding fields of study in sponges and industrial application.In this thesis,we based on the latest framework of glass sponges and focused on taxonomic study of deep-sea sponge samples(suspected new species)collected by Jiaolong Submersible on Cruise 31 and Cruise 35 in 2013 and 2014,respectively.We also verified the results with molecular method.The research results of this study,to a certain extent,contributed to the progresses of taxonomic study of Hexactinellid sponges in China.According to the descriptions of previous journals,we analysed 12 relatively complete sponge samples(suspected new species),and two of them showed significant amplification results of partial 16S rDNA gene.All of the 12 suspected new species were collected near CCFZ and Caiwei Guyot.They are demonstrated to be different species belonging to eight genera,five families,and two orders,among which we described seven new species and two new subspecies.The other three spieces have been published on Zootaxa which we included in this thesis as well.In family Hyalonematidae,we discovered three new species and named them with Hyalonema(Onconema)caiweiense sp.nov.,Hyalonema(Prionema)laxodiscum sp.nov.,and Hyalonema(Prionema)papillatum sp.nov..The accepted species of family Pheronematidae are Platylistrum subviridum,Poliopogon canaliculatus and Semperella retrospinella.Further more,we updated family Pheronematidae with a new species named Semperella reticulata sp.nov.and a new subspecies named Poliopogon amadou flatus ssp.nov..Moreover,in Family Euplectellidae,we described two new species as follows,named with Bolosoma onychaster sp.nov.and Saccocalyx verecundiflorus sp.nov..In family Leucopsacidae,we reported a new species named Chaunoplectella megapora sp.nov.,which was submitted to Zootaxa.At last,we managed to illuminate a new subspecies belonging to Rossellidae and named it with Caulophacus(Caulodiscus)onychohexactinus similis ssp.nov.We made pretests for suitable molecular marker repeatedly and results showed that primers partial gene of 16S rDNA had the highest amplification efficiency;thus we take primers 16Slfw/16SH_mod to amplify the target gene fragment of partial 16S rDNA using above-mentioned 12 species and constructed two phylogenetic trees.The results demonstrated that 16S rDNA gene was conservative and reflected reasonable relationship.However,the annealing temperature varied in different species,and thus every single sample had to been amplified under different temperature gradients.Generally speaking,the amplification efficiency of 16S rDNA was not high enough for deep-sea sponges.More tests on changing the experimental conditions are needed,as well as combing 16S rDNA with other markers in order to construct the phylogenetic tree and to improve the whole systematic framework of deep-sea sponges. |
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