A new radiolarian species Clathrocorys gracilis from northern South China Sea

A new species, Clathrocorys gracilis nov. spec., of Tripocyrtidae （Radiolarians： Nassellaria） from surface water in northern South China Sea, is described in this paper. The new species has four radial beams arising from the cephalic base centre, each foot with cup-shaped structure and ramified bar in the proximal section （near cephalic base）, and each wing with a large mesh in the middle, a medium mesh and a small mesh on each side respectively.     

A new species, Gerres septemfasciatus （Perciformes： Gerreidae） from the Chinese coastal waters of the South China Sea

We describe a new species of gerreid fish,Gerres septemfasciatus,based on four specimens collected from the northern South China Sea.G.septemfasciatus most closely resembles G.limbatus in general appearance.However,G.septemfasciatus is distinguished from the latter and other congeners by having 3 to 3.5 scales between the base of the fifth dorsal spine and lateral line.This species has a distinctive color pattern,including 7-8 regular,vertical,blue-grayish bands on its side.The distribution of this species ...     

A new species of Cerithium （Gastropoda： Cerithiidae） from the South China Sea

Specimens of a new species of Cerithiidae, Cerithium mangrovum n. sp., were collected during two surveys along the coasts of Hainan and Guangdong Province, China. Usually associated with potamidid snails, this species often occurs in large populations between the mid-high tidal zones in a range of habitats, including mangroves, grass beds, silt, mud, and coral reefs. C. mangrovum n. sp. has a slender and tapering shell and the straight-sided whorl bears three aligned beaded spiral cords. The thick outer lip has a wide posterior sinus. It morphologically resembles C. coralium Kiener, 1841. The shell of C. coralium is usually larger and wider and the spiral cords are not as beaded as in C, mangrovum n. sp. Its radula has a rachidian tooth with a shallow, wide, median basal projection while the rachidian tooth of C. mangrovum n. sp. has a moderately long, median basal projection.     

A NEW SPECIES OF THE GENUS NEROCILA （ISOPODA： CYMOTHOIDAE） FROM THE EAST CHINA SEA

A new species of cymothoid Isopeda, Nerocila donghaiensis, collected from the body of a sciaenid fish, Johnius sp., is described in the present paper. The new species can be distinguished from the other species of genus Nerocila by its endoped of uropods with deep notch, sharply serrated on the lateral margin and strongly serrated on the medial margin; antennule with 1 st article swollen; dactyli of pereopods Ⅰ, Ⅱ, Ⅳ, Ⅴ swollen.     

A new species of the genus Arcoscalpellum (Cirripedia,Thoracica, Scalpellidae) from deep waters in the South China Sea

A new species of deep-water barnacle that belongs to the family Scalpellidae is described from the South China Sea. A rcoscalpellum liui sp. nov. is morphologically similar to A rcoscalpellum gryllum Zevina,but differs from the latter by the absence of longitudinal striae on the capitular plates and the presence of caudal appendages with few terminal setae.     

Descriptions of three new species of Mitridae （Mollusca： Gastropoda） from South China Sea

Three new species of Family Mitridae （Mollusca： Gastropoda） from the South China Sea are described in the present paper. They are Ziba aglais sp. nov. B. LI ＆ S. ZHANG, Neocancilla daidaleosa sp.nov. B. LI ＆ X. LI, and Mitra holkosa sp. nov. B. LI. Their systematic positions are also discussed.     

A new species ofPraebebalia (Crustacea: Brachyura: Leucosiidae) from East China Sea

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｇｅｎｕｓＰｒａｅｂｅｂａｌｉａｗａｓｅｓｔａｂｌｉｓｈｅｄｂｙＲａｔｈｂｕｎ ,1 91 1 .Ｉｔｓｃａｒａｐａｃｅｉｓｂｒｏａｄｅｒｔｈａｎｌｏｎｇａｓｌｏｎｇａｓｂｒｏａｄ ,ｏｒｓｌｉｇｈｔｌｙｌｏｎｇｅｒｔｈａｎｂｒｏａｄ ;ｔｈｅｐｏｓｔｅｒｉｏｒｂｏｒｄｅｒｉｓｕｓｕａｌｌｙａｒｍｅｄｗｉｔｈａｓｐｉｎｅｏｒｔｕ ｂｅｒｃｌｅｏｎｅａｃｈｓｉｄｅ ,ｔｈｅｈｅｐａｔｉｃａｎｄｉｎｔｅｓｔｉｎａｌｒｅｇｉｏｎｓａｒｅｄｉｓｔｉｎｃｔｌｙｅｌｅｖａｔｅｄ ;ｔｈｅｃｈｅｌ…     

Spatio-temporal variations in the siphonophore community of the northern South China Sea

To understand how hydrological and biological factors affect near-to off-shore variations in the siphonophore community,we sampled zooplankton at 82 stations in the northern South China Sea during summer,winter,and spring.Forty-one species of siphonophore were collected by vertical trawling.The species richness of siphonophores increased from the nearshore to offshore regions in all three seasons of investigation,with maximum richness in summer and minimum richness in winter.The abundance of siphonophores was also higher in summer than in spring and winter,concentrated in the nearshore region in the warm season and scattered in the offshore region in the cold season.Four siphonophore groups were classified according to the frequency of occurrence:nearshore,near-offshore,offshore,and tropical pelagic.Among them,the nearshore group had higher abundance nearshore compared with the offshore.The tropical pelagic group had higher species number offshore than nearshore.Spatial and temporal fluctuations in taxonomic composition and abundance of siphonophores were due to the influence of the coastal upwelling and surface ocean currents of the South China Sea,driven by the East Asia monsoonal system.     

Two New Species of the Genus finocladia Kylin （Chordaria-les, Phaeophyta） from Yellow Sea Coasts of China

Two new species of the genus Tinocladia Kylin, T. gracilis sp. nov. and T. microsporangii sp. nov,, are described. T. gracilis is characterized by its slender frond, variable size, infrequently branched medullary filaments, and short assimilating filaments with 2 - 7 cells. T. microsporangii is characterized by its medullary cells which are slightly larger than sub-cortical ones; narrow sub-cortical layer, usually consisting of 4- 6 cells and very small unilocular sporangia. The holotypes are deposited at the Herbarium of the Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.     

Marine biofouling in offshore areas south of Hainan Island, northern South China Sea

ＩＮＴＲＯＤＵＣＴＩＯＮＢｉｏｆｏｕｌｉｎｇｃａｎｃａｕｓｅｒｏｕｇｈｎｅｓｓｏｆｓｕｂｍｅｒｇｅｄｓｕｒｆａｃｅｓｏｆｍａｒｉｎｅｓｔｒｕｃｔｕｒｅｓ(Ｃｈａｋｒａｂａｒｔｉ,1991),ｉｎｃｒｅａｓｅｈｙｄｒｏｄｙｎａｍｉｃｌｏａｄｉｎｇｓ(ＷｏｌｆｒａｍａｎｄＴｈｅｏｐｈａｎａｔｏｓ,1985),ａｃｃｅｌｅｒａｔｅｃｏｒｒｏｓｉｏｎｐｒｏｃｅｓｓ(Ｐａｔｉｌｅｔａｌ.,1988),ａｎｄｉｍｐｅｄｅｕｎｄｅｒｗａｔｅｒｉｎｓｐｅｃｔｉｏｎａｎｄｍａｉｎｔｅｎａｎｃｅ(Ｈｏｕｇｈｔｏｎ,1978).Ｔｈｅｌａｃｋｏｆｄ…     

On a new species ofPavlova (Prymnesiophyceae) from China

Pavlova viridis sp. nov. is described on the basis of light and electron microscope observations. The material was collected from the coast of haiyang county of Shandong, China. It is characterized by 1) yellowish green to green chloroplast, 2) rudimentary short flagellum 0.3 μm long and hook-shaped, 3) long flagellum with small spherical knob-scales, 4) absence of pyrenoid and stigma, and 5) marine habitat. This new species andP. salina seem to be most closely related to each other but their colour, the insertion of their three appendages, the shape of their knob scales, and their cell periplasts are quite different from one another. Contribution No. 1879 from the Institute of Oceanology, Academia Sinica     

中国鲉形目棘鲬属一新纪录种——丝鳍棘鲬

【目的】记述中国南海海域棘鲬属的一新纪录种,以厘定中国南海海域棘鲬属的分类。【方法】2019年4月于中国南海北部海域海南岛东南渔场采集棘鲬属样品,采用形态学鉴定方法研究其形态特征,描述其生态习性,编制中国棘鲬属分种检索表。【结果与结论】样品中有6尾为中国新纪录种——丝鳍棘鲬Hoplichthys filamentosus Matsubara&Ochiai,1950。主要特征:体延长,平扁,向后渐狭小,背缘低平,腹缘平直;背鳍VI,14~15;臀鳍17;胸鳍13+ⅲ;腹鳍Ⅰ-5;尾鳍17;侧线骨板27;鳃耙2+11~12;体具几条不明显深色横带;胸鳍具黑色斑点;第1背鳍分布黄色斑点,具黑色小点和黑边;第2背鳍中部分布黄色圆斑,每1鳍条根部具黄色圆斑;腹鳍白色,无斑纹;臀鳍无明显斑纹;尾鳍后缘具黑边,中部较随机分布黄色圆斑,下叶颜色较深。该种雌雄异形:1)雄性下颌骨腹外侧具棘,雌性则隐没皮下;2)雄性第2背鳍鳍条均显著延长呈丝状,雌性则无显著延长。     

A new species of Nassarius (Gastropoda: Nassariidae) from the western Pacific Ocean

This paper describes a new species of Nassarius from the South China Sea,which was recognized when re-sorting the collection of Nassariidae in the Marine Biological Museum,Chinese Academy of Sciences,Qingdao,China.The shells were collected during several investigations,including the National Comprehensive Oceanic Survey in 1958-1959,and the China-Vietnam Co-Investigation on Marine Resource of the Beibu Gulf during 1959-1962.The morphology of the shell and the radula places the new species of Nassarius within the subgenus Zeuxis.It is named Nassarius(Zeuxis) nanhaiensis sp.nov.     

Marine fouling in offshore areas east of Hainan Island, northern South China Sea

INTRODUCTIONBiofoulingonunderwaterpartsofman mademarinestructuresisamajoreconomicandtechni calproblemhavinginternationaldimensionsforthedevelopmentofoceanengineeringbecauseitnotonlyincreasesstaticandhydrodynamicloading,butalsoaffectscorrosioncharacteristicsandim pedesunderwaterinspectionandmaintenance (CallowandEdyvean ,1 990 ) .Duetodifferencesingeographicalpositionsandenvironmentalconditions,thedistributionofsessileorganismsvarieswitharea .Therefore ,understandingtheformationofbiofoulin…     

Stability of submarine slopes in the northern South China Sea: a numerical approach

Submarine landslides occur frequently on most continental margins. They are effective mechanisms of sediment transfer but also a geological hazard to seafloor installations. In this paper, submarine slope stability is evaluated using a 2D limit equilibrium method. Considerations of slope, sediment, and triggering force on the factor of safety (FOS) were calculated in drained and undrained (Φ=0) cases. Results show that submarine slopes are stable when the slope is <16° under static conditions and without a weak interlayer. With a weak interlayer, slopes are stable at <18° in the drained case and at <9° in the undrained case. Earthquake loading can drastically reduce the shear strength of sediment with increased pore water pressure. The slope became unstable at >13° with earthquake peak ground acceleration (PGA) of 0.5 g; whereas with a weak layer, a PGA of 0.2 g could trigger instability at slopes >10°, and >3° for PGA of 0.5 g. The northern slope of the South China Sea is geomorphologically stable under static conditions. However, because of the possibility of high PGA at the eastern margin of the South China Sea, submarine slides are likely on the Taiwan Bank slope and eastern part of the Dongsha slope. Therefore, submarine slides recognized in seismic profiles on the Taiwan Bank slope would be triggered by an earthquake, the most important factor for triggering submarine slides on the northern slope of the South China Sea. Considering the distribution of PGA, we consider the northern slope of the South China Sea to be stable, excluding the Taiwan Bank slope, which is tectonically active.     

Variation in downwelling diffuse attenuation coefficient in the northern South China Sea

The diffuse attenuation coefficient for downwelling irradiance （Kd（λ）） is an important parameter for ocean studies. Based on the optical profile data measured during three cruises in the northern South China Sea in autumn from 2003 to 2005, variations in the Kd（λ） spectra were analyzed. The variability of Kd（λ） shows much distinct features in both magnitude and spectra pattern, it is much higher in coastal waters than that of open oceanic waters; and the blue-to-green （443/555） ratio of Kd（λ） tends to increase with chlorophyll a concentration （[Chl-a]） from open ocean to coastal waters. These characteristics can be explained most by the increase of aw＋p（443）/aw＋p（555） with [Chl-a]. In short waveband, the relation between Kd（λ）-Kw（λ） and [Chl-a] can be well described by a power law function, indicating the large contribution of phytoplankton to the variations in Kd（λ）. As for the spectral model of the diffuse attenuation coefficient, there are good linear relationships between Kd（490） and Kd（λ） in other wavelengths with own slope and intercept of a linear functions in the spectral range 412-555 nm. Kd（490） is well correlated with the spectral ratio of remote sensing reflectance; and should enough measurement data are given, this empirical algorithm would be used in the Kd（λ） retrieval from ocean color satellite data. The variation in Kd（λ） provides much useful information for us to study the bio-optical property in the northern South China Sea.     

Accumulation and exploration of gas hydrate in deep-sea sediments of northern South China Sea

The large deep-sea area from the southwestern Qiongdongnan Basin to the eastern Dongsha Islands,within the continental margin of northern South China Sea,is a frontier of natural gas hydrate exploration in China.Multiform of deep-sea sedimentations have been occurred since late Miocene,and sediment waves as a potential quality reservoir of natural gas hydrate is an most important style of them.Based on abundant available data of seismic,gravity sampling and drilling core,we analyzed the characteristics of seismic reflection and sedimentation of sediment waves and the occurrence of natural gas hydrate hosted in it,and discussed the control factors on natural gas hydrate accumulation.The former findings revealed the deep sea of the northern South China Sea have superior geological conditions on natural gas hydrate accumulation.Therefore,it will be of great significance in deep-sea natural gas hydrate exploration with the study on the relationship between deep-sea sedimentation and natural gas hydrate accumulation.     

Phytoplankton pigment patterns and community composition in the northern South China Sea during winter

Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chl a)-like type, divinyl chlorophyll a (DV Chl a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.89±0.63 in the upper 50 m and 0.16±0.06 below 50 m depth. With increasing depth, APP decreased and photo-synthetically active radiation was attenuated. There was an obvious succession in the phytoplankton community from inshore to the open sea. Diatoms were dominant in the inshore region, while pelagophytes, Prochlorococcus, cyanobacteria and prymnesiophytes were dominant in the open sea. The vertical distribution of phytoplankton also differed greatly from inshore to the open sea. In the coastal and shelf region, diatoms were important components in the whole water column. Cyanobacteria also had a high abundance at the Subsurface Chlorophyll a Maxima (SCM) in the shelf region. In the slope and open sea, Prochlorococcus and cyanobacteria were important groups above the SCM, while pelagophytes dominated below the SCM.     

Phytoplankton pigment patterns and community composition in the northern South China Sea during winter

Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chl a)-like type, divinyl chlorophyll a (DV Chl a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.8...