The Taxnomy Of Deep Sea Sponges From The West Pacific Ocean And Preliminary Study Of Their Molecular Phylogeny

Porifera can be easily found in deep ocean. Morphological plasticity and limited information obtained from spicules and skeletons make deep-sea sponge classification very difficult. The sponge taxonomy studies in China are very limited, there are almost no recodes for deep sea sponge in China. This study performed taxonomic studies for deep sea sponges, provided valuable information for their biodiversity and distribution.In the study of this thesie, traditional morphological method was used to classify the sponge samples. The study samples were collected respectively from the South China Sea, Okinawa Trough and Yap area, West Pacific Ocean, during 2013 to 2015.They were found from the environment from seamounts, hydrothermal vents, cold seeps and other deep-sea areas. After sorting the samples, 24 sponges species belonging to 2 classes, 6 orders, 17 families, 21 genera were identified, in which 2genera, 10 species were new to science. Among the 24 species, 7, 7, 10 were found from the South China sea, Okinawa Trough and Yap area respectively. In the samples,3 specimens were dead when they wre collected, it was too hard to identify them into species level, however, it is clear that the present three diffirent families. All the species were described detailedly, with the SEM illustration of spicules and skeleton.This study is the first approach on the deep-sea sponge in China. The above results provide important supplements for the deep sea sponge taxonomy study in China.They can be also served as valuable background for the subsequent sponge taxonomic researches.The phylogenetic relationships of the 24 species and their related species were also studied with molecular methods. Partial mitochondrial 16 S ribosomal RNA genes of 21 species were amplified(the three species with dead specimens were not included in the molecular study). Based on the amplicons, a phylogentic tree was built and performed preliminary investigation into the relationship of these species. The primers for sponge molecular research were also experimented, because up to date,there were no suitable universal primers for all the sponges groups. The existeduniversal primers were usually corresponding to different taxonomic categories. In this study, primer 16S1 fw and 16 SHmod were found efficient for both our Demospongiae and glass sponge samples. The availability of this pair of primers in other sponge groups should be test in the subsequent studies.