Preliminary Taxonomical Study Of Diatoms From Hainan Island,China

Hainan Island is the second largest island in China,located in the tropics and has a tropical monsoon climate.It has abundant fresh water resources and diverse habitat types.During our investigation,algal samples were collected in July 2014 and July2019 from Wuzhi Mountains,Diaoluo Mountains,Qixianling Mountains,Jianfeng Mountains,Wuzhizhou Island,Guyin Waterfall,Songtao Reservoir,Yaolong Reservoir,Bawangling Mountains and Limu Mountains in Hainan Island,China.The habitats include: streams,springs,lakes,puddles,rivers,wet walls,waterfalls,reservoirs,ponds,etc.A total of 302 samples were collected and more than 600 perminent slides were made.Light microscope(ZEISS Imager.A2)and scanning electron microscope(Hitachi S-4800)were used to study the diatom.The main results are as follows:1.Diatom biodiversity in Hainan island are really high,a total of 350 taxa,belong to 32 families,77 genera were identified.Habitats information and morphological characteristics of each taxon was described.Light microscope photos are provided to all species.SEM pictures are given to some taxa.2.A total of 14 new species were identified from Hainan Island,namely: Qinan hainanii Liu & Kociolek,Qinia sinica Liu & Kociolek,Brachysira subirawanae Kociolek & Liu sp.nov.,Sellophora wangii Liu & Kociolek sp.nov.,Qinia sp.1,Orymymba sp.1,Gomphonema sp.1,Gomphonema sp.2,Neidium sp.1,Pinnularia sp.1,Sellaphora sp.1,Sellaphora sp.2,Sellaphora sp.3,Stauroneis sp.1.Eighty-one taxa were newly recorded species of China.Diaoluo Mountains are the hotspots for new species,with 11 new species were observed from here.3.Diaoluo Mountains have the most abudant diatom biodiversity,227 taxa were observed;in Jianfengling Mountains,178 taxa were found;in Wuzhi Mountains 176 were observed;in Limu Mountains 148 taxa were identified;in Bawangling Mountains118 were observed;88 taxa were observed from Qixianling Mountains;70 taxa were observed from Guyin Waterfall;36 taxa were observed from Shihua Water Cave;29taxa were observed from Songtao Reservoir;20 taxa were observed from Yaolong Reservoir;17 taxa were observed on Wuzhizhou Island.Some species have relative restricted distribution area and are only observed in certain areas or habitats.Forexample,Denticula elegans K�tzing is only distributed on Wuzhizhou Island;Eunotia monodon Ehrenberg is only distributed on Bawangling Mountains.4.Most species are distributed in streams,with a total of 270 taxa observed;rivers and wet walls are next,with 179 and 168 taxa were observed respectively.Species distributed in lakes,puddles,springs,waterfalls,reservoirs,and ponds are relatively less.5.Diatom biodiversity from Hainan Island and other region within China,such as Tibet,Xinjiang,Zoige,and the Greater Xing'an Mountains are compared.In terms of the number of species,Hainan island really have higgly biodiversity of diatom Although the sepecies number in Hainan Island are not the highest,but 227 taxa were only found from Hainan Island.present a certain geographical distribution pattern.