Abstract:Research of species distribution and diversity of the coral reef fishes was conducted by the method of line intercept transect,taxonomic diversity index,relative abundance and similarity index,according to the monitoring data investigated along the east and south coasts of Hainan island from 2004 to 2013.The results showed that,there were 6 orders, 32 families, 64 genera and 130 species of coral reef fishes with density of a decreasing trend from south to north approximately.And Perciformes was in the absolute dominance.Average diversity index of the family was 4.41 when the genera was 3.09,and normalization G-F was 0.30; Relative abundance of coral reef fishes of Perciformes has possessed absolute dominance.Six higher relative abundance families were Pomacentridae,Labridae,Chaetodontidae,Apogonidae,Tetraodontidae and Centriscidae; It was very similar in orders with similarity index between 0.86 to 1,when it was low as Family,Genus and Species,all of them below 0.5.There were many varieties and abundant species in the shallow reefs along the east and south coasts of Hainan Island,through the Jaccard's similarity index analysis.Length of fish body ranged 6～10 cm,followed by 0 to 5 cm,few of them 21～40 cm.This paper hopes to provide basic data and theoretical basis for protection of coral reef ecosystem and reef fishes,through the discussion of the species distribution and diversity of the coral reef fishes along the east and south coasts of Hainan Island in nearly a decade.

Abstract:Based on the survey of macrozoobenthos from the Yangtze River estuary in summer during 2011—2014,this paper analyzes inter-annual variation of species composition,abundance and biomass.The results showed that a total of 60 species were collected in 2011,58 species in 2012,78 species in 2013,and 83 species in 2014.During 2011—2013,the mean abundance and the mean biomass decreased year by year.Meanwhile,the mean abundance and the mean biomass in the diluted water region of the Yangtze River estuary were noticeably higher than those of the Yangtze River estuary.Both the mean abundance and the mean biomass,however,rose again significantly in 2014.The biodiversity index (H'),richness index (D) and evenness index (J') were basically stable,slightly lower in 2012 and exhibiting an overall recovery trend later.The dominant species were Heteromastus filiformis,Cossurella dimorpha,and Gammarus sp.Polychaetes were the dominant group every year except in 2013,in which no dominant species was detected.The inter-annual variation in community structure was relatively large and the community components showed a trend of increasing abundance year by year.The results of this paper provide a scientific basis for further study of environmental change and macrozoobenthos community succession in the Yangtze River estuary.

Abstract:To study the life history processes and morphological traits of Sargassum horneri from the Sargassum seaweed bed of Gouqi Island,this study first conducted the investigation of the growth and reproduction during an annual cycle of Sargassum horneri,and 16 related biological parameters including individual length,blade,vesicle and receptacle were analyzed.Experimental results showed that growth of Sargassum horneri can be divided into 4 phases within the year according to the occurrence of different biological structures in its life history:(1) seedling period during July to August,during which plants consist of stalk,branch and blade briefly,plants grow with an average rate of 1.52 mm/d; (2) adult period during August to April of next year, all biological structures were consummated and successively recorded the occurrence of vesicle,secondary branch and receptacle in September,November and April of next year respectively,and plants grow with an average rate of 2.01 mm/d; (3) reproduction period during April to May,the occurrence of receptacles indicated the arrival of reproduction period,while the concentrated dispersion of ovums indicates the arrival of “climax” of reproduction period,and plants grow with an average rate of 3.80 mm/d;(4) senescence and degeneration period during May to June,the majority of plants begin ageing with detachment of biological structures,while the average growth rate of plants reaches 0.99 mm/d due to the supplement of immature individual.In the 16 biological parameters detected,10 parameters including length,individual biomass and primary branch length showed a significant seasonal variation(P <0.05).This warm-temperate species exhibited a phenological behavior intermediate between tropical and cold-temperate species of Sargassum. Analysis of within- and between-individual stability of 10 morphological parameters indicated the lowest stability of primary branch length(Ed=95),which belongs to the best parameters for distinguishing species and may provide us with the basis for morphology research and species identification of Sargassum.

Abstract:The present study investigated the species composition,dominance and characteristics of macrobenthic fauna within 13 sampling stations from eight survey cruises in Yangtze River estuary during February,May,August and November,in 2013 and 2014.The Shannon Wiener diversity index (H),Pielous species evenness (E),species abundance (D),dominance index (Y) were used to evaluate Yangtze estuary community characteristics.In addition,the community structures of macrobenthic fauna were analyzed by hierarchical cluster and non-metric sort multidimensional scaling (NMDS).The results showed that a total of 49 species of large benthic animals were obtained in 2013,and 40 species were collected in 2014.The temporal variation of macrobenthos in different seasons changed obviously in the same year,and the total number of species decreased in 2014.The highest abundance and biomass appeared in the spring and autumn,2013 and in winter and summer,2014.The biomass of different seasons was obviously different in 2013 and 2014.Crustaceans were characteristic of macrobenthos in both 2013 and 2014,and the dominant species belonging to fish increased.Higher diversity was observed in the autumn,2013 and in the spring,2014 comparzed to the other seasons in the same year.Generally,and the diversity index showed an increasing tendency during the investigation of two years' period.Hierarchical cluster analysis and NMDS analysis showed that the macrobenthic community of the Yangtze River estuary constituted two groups in 2013,and community in the summer,autumn and winter were grouped from that in spring.In 2014,community in spring,summer and autumn were clustered,and was separated from community in the winter.ABC curve showed that macrobenthic communities in subtidal zones were moderately affected in the four seasons in 2013.In contrast,in 2014,no significant effect on macrobenthic community was observed in the spring,summer and autumn,and macrobenthic community was only affected with heavily moderate interference in winter.The tendency in decreasing interference was observed during the investigation period.

Abstract:For a better understanding the effects of environmental variables on catch rates of bigeye tuna (Thunnus obesus),the catch rates of bigeye tuna and environmental variables were collected in longlining surveys in waters near Cook Islands from Sept.8,2013 to Dec.31,2013.Data included:hook depth data,temperature and chlorophyll-a concentration,three-dimensional sea current vertical profile data,operating parameters and catch data.Stepwise regression was used to develop the hook depth calculation model.Statistics and clustering analysis were used to analyze the effects of environmental variables on bigeye tuna catch rate.Results showed that the depth,temperature,chlorophyll-a concentration,east-west current,south-north current,horizontal current and vertical current range with the high catch rate for bigeye tuna were 120.0～199.9 m,13.0～14.9 ℃,0.200～0.239 μg/L,0.1～0.2 m/s,-0.2～0 m/s,0.1～0.4 m/s,and 0.04～0.05 m/s,respectively.Results suggested that more hooks should be deployed in the environmental variables' range with the high bigeye tuna catch rate when fishing in the waters near Cook Islands and targeting bigeye tuna.

Abstract:The Xiaolangdi reservoir is a key water-control project located in the middle reaches of the Yellow River in Henan Province,China.Since 2002,the water and sediment regulation operations have been conducted in this area during June or July every year.In autumn,juvenile fish is artificially released into the reservoir to prevent the fishery resources from decreasing as a result of the project.In order to know the influence of this project on the fishery resources,acoustic investigations on fishery resources were conducted in the main channel areas from the dam to the Yellow River Three Gorges in the Xiaolangdi reservoir.A split-beam scientific echo sounder (Simrad EY60,70 kHz,Norway) was used on November 25,2013 (after the water and sediment regulation) and May 22,2014 (before water and sediment regulation),respectively.The average density of fishery resources,the population size and the spatial distribution in different areas of reservoir were surveyed and estimated according to the survey on fish target strength in situ and the use of echo integration methods.As a result,the acoustic integral value:Nautical Area Scattering Coefficient (NASC) in the reservoir were 29.38 m²/nm² and 49.77 m²/nm² in November 2013 and May 2014,respectively,also the average density of fishery resources were 0.016 ind/m² and 0.290 ind/m², and the population size were 41.56 t and 606.70 t,respectively.For the horizontal distributions of fishery resources in the different investigated areas,the average density of fishery resources in the areas are as follows:areas close to the dam saw a horizontal distribution of 0.016 ind/m²; the middle reaches of the river with 0.023 ind/m²; the upper reaches with 0.024 ind/m²; and Three Gorges area with 0.009 ind/m² in November 2013.In May 2014,the horizontal distributions of fishery resources for the same locations were 0.848 ind/m²,0.248 ind/m²,0.077 ind/m²,0.083 ind/m²,respectively.The NASC in the corresponding areas were 5.61 m²/nm²,4.60 m²/nm²,5.52 m²/nm²,6.47 m²/nm² in November 2013; and 94.09 m²/nm²,53.18 m²/nm²,28.27 m²/nm²,29.38 m²/nm² in May 2014 for the respective area segments.The fishery resources were distributed mainly in the upper and middle reaches of the reservoir in November 2013,and in the lower and middle reaches in May 2014.Fish in the reservoir showed the characteristics of layered vertical distribution.In the area of the Yellow River Three Gorges,fish is mainly distributed in the 10 m to 20 m water layer.In the main channel area,fish is mainly distributed in the surface water layer and the 20 m to 30 m layer.The fish target strength (in situ) had respectively highest proportions of -59.5 dB in November 2013,and -56.5 dB to -53.5 dB in May 2014.This shows that the fish size was relatively small and the body length increased six months later.These results support the idea that the fishery acoustic survey is an effective method for the fishery resources assessment in the Xiaolangdi reservoir.

Abstract:The knowledge of diel vertical migration (DVM) of Antarctic krill aggregation (AKA) in the winter season will provide basic data to study the forming mechanism of fishing ground and provide the reference to study the overwintering strategy.Based on the data collected by the fishery survey on Antarctic krill population in the South Georgia Island during the austral winter 2013,the present study analyzes the DVM of AKA in the South Georgia Island.The results show average depth of AKA maintains 100 m to 300 m under sea surface,and the deepest and shallowest depths the of AKA occur at sunrise and night respectively.The average depth of AKA is deepening from July to September.The average depths of AKA show a significant monthly difference at night,in the day and at dusk.AKA often occurs in the deeper layer in the day and stays at surface at night.

Abstract:In order to investigate the community structure characteristics of molluscs in the rock intertidal zone of Zhejiang,field sampling was carried out including eight rocky intertidal sections in Apr.and Oct.2009.A total of 27 species in two seasons were identified,belonging to 3 classes,11 orders,16 families and 22 genera.The molluscs community in the intertidal zone of Zhejiang was mainly composed of subtropical species,including 13 species recorded,and followed by temperature widespread species and temperate species,with 12 species and 2 species,respectively,generally in accordance with the taxonomic features of the East China Sea.The average molluscs biomass and density in spring were 156.15 g/m² and 83.47 ind./m²,respectively; which were higher than those in autumn,being 88.04 g/m²,63.05 ind./m²,respectively.Dominant species were Thais clavigera,Nerita albicilla,Barbatia obliquata,Nerita yoldii and Septifer bilocularis in spring; T. clavigera,Monodonta labio,B.obliquata,N.albicilla,Septifer virgatus and Chlorostoma rustica in autumn.Dominant species of molluscs varied with different seasons,indicating their functions in the community changed with seasons.The index of Shannon-Winner was from 1.13 to 2.77,the average being 1.85.The index of Pielou's evenness was from 0.33 to 0.77,the average being 0.64.The index of Margalef's species richness was from 0.80 to 2.02,the average being1.27.The community structure of molluscs had been studied by Bray-Curtis similarity clustering and non-metric multidimensional scaling (MDS) analysis.The community could be spatially clustered into three groups during Spring:the first was sections including Nanji Islands and Dongtou,the second was sections including Sanmen,Xiaowushitang,Xiangshan Bay,Ninghai and Xiushan,and the third was Shitang.However,autumn was also clustered into three groups,the first was sections including Sanmen,Xiaowushitang,Xiangshan Bay and Xiushan,the second was sections including Dongtou,Ninghai and Shitang,and the third was Nanji Islands.SIMPER analysis found that the average similarity rate between each section in the group was higher than 37%,and the average difference rate between groups was higher than 66%.

Abstract:Coastal fishing grounds are the important traditional fishing grounds in China.But coastal fishery resources have been immersed in the conditions of unsustainable development because of overfishing、environmental pollution and habitat destruction in recent years.The paper points out the difficulties which fishery management is faced with,and on this basis,analyzes deeply the root of difficulties.Finally,the paper puts forward the corresponding countermeasures from the system innovation of fishery resource management; improvement of fishery management means; improvement of the support system,the planning of fishing grounds,the establishment of demonstration area,hoping to provide decision-making reference for fisheries department.

Abstract:Based on bottom trawl data from August 2006 to October 2007,seasonal variations in the fish community structure and diversity in the north of Liaodong Bay were analyzed using the index of relative importance(IRI),species diversity indices,and multivariate methods.A total of 39 species were collected,belonging to 8 orders,23 families,and 35 genera.Most of them were warm-temperature species and warm-water species.There were obvious succession of dominant species in four seasons,the seasonal dominant species whose IRI value ≧1000 were Chaeturichthys stigmatias,Synechogobius ommaturu,Larimichthys polyactis,Liza haematocheila,Platycephalus indicus,Protosalanx chinensis,Lophius litulon,and without symbiotic species in four seasons.Compared with the data in 1998,the dominant species have largely changed.The Margalef species richness index(D) ranged from 0.40 to 1.69,the Shannon-Winner diversity index(H') ranged from 0.39 to 1.45,the Pielou evenness index(J') ranged from 0.43 to 0.75,and all of three diversity indexes changed significantly among seasons(ANOVA).ANOSIM analysis also indicated that fish species composition varied significantly among seasons.The SIMPER analysis revealed that Larimichthys polyactis,Chaeturichthys stigmatias,Synechogobius ommaturus,Konosirus punctatus, Lophius litulon,Liza haematocheila,Platycephalus indicus,Scomberomorus niphonius,Pterogobius zacalles,Cynoglossus joyneri were primary discriminating species in the fish community among seasons.Based on the correlation between fish community structure and environmental factors using correlation analysis and BVSTEP,it is indicated that water temperature was primary environmental factor which led to seasonal changes of fish community in the north of Liaodong Bay.The study can provide a scientific basis for protecting ecological environment,fishery resources conservation and sustainable exploitation.

Abstract:Shannon-Wiener diversity index is commonly used in measuring the community species diversity or assessing the ecological status of marine environments.There are two methods to compute the Shannon-Wiener diversity index in the surveyed region,which is calculated based on each sample data(Method 1) or based on the pooled data of the survey region(Method 2).In order to find out which method is better to reflect the species diversity of the survey region,as well as to examine the relationship between the Shannon-Wiener diversity index and the sample size,a comparative study of these two methods was carried out using simulation study based on the data from the macrozoobenthos survey in tidal flat wetland of northwestern Jiaozhou Bay in 2009.The results showed that the Shannon-Wiener diversity index calculated by Method 1 was lower than that from Method 2.The estimated Shannon-Wiener diversity index calculated by Method 1 was independent of sample size,and the Shannon-Wiener diversity index by Method 2 became greater with the sample size increasing,and then kept stable approaching the “true value” at the sample size of 20.Both the relative estimation error (REE) and the relative bias (RB) of the diversity index estimation from Method 2 were getting smaller when the sample size was greater than 20,which indicated that the sample size affected the calculating results of Method 2.Method 2 with enough or optimal sample size would be used in estimating the species diversity or in evaluating the ecological quality of the entire survey area,which would objectively reflect the status of species diversity in the survey area.

Abstract:The ecosystem approach to fisheries (EAF) emerged in 2001 by FAO.It took into account the important impact of ecosystem on fisheries and added the concerns about the ecological framework into fisheries management.EAF based on two theories,the ecosystem management and fisheries management,proposing the EAF framework:basing on the dependency of ecosystem health and human welfare,paying attention to multi-species management,balancing the three dimensions targets of the ecology,the humanities and the mechanism,and aiming to achieve the fisheries sustainable development.This paper mainly describes the origin,definition,basic principle and elements of EAF,and briefly introduces the practice foundation of EAF and the model construction,and finally compares the EAF with EBFM(ecosystem-based fisheries management).Although the objectives,content and paradigm of EAF are clear,the EAF relative lack of practical experience which is still in improvement and development phase.EAF is the developing prospect of fishery management.The introduction and study of EAF is very important for improving the sustainable development of fisheries in China.

Abstract:Monthly variation of biology characteristics,density and its spatial distribution of O.oratoria in Laizhou Bay,together with the influence of environmental factors,were analyzed according to the bottom trawl data of 9 surveys from May 2011 to April 2012,in order to provide theoretical basis for utilizing and protecting the resources of O.oratoria.The monthly variation of density(both biomass and individual number) was August >July >September >October >May> November> June> April> March.The body length of O.oratoria was 41-171mm and the average body length was the lowest in May by 102mm and the highest in July by 118 mm.The body weight of O.oratoria was 0.30- 68.00 g and the average body weight was the lowest in May by 13.64g and the highest in July by 17.67g.The individual fatness coefficient was the highest in October both for the female(1.49) and the male(1.56).The trend of the monthly change of fatness coefficient was on the decline in May-July,on the rise in August-October and on the decline after November again.The difference of fatness coefficient was not significant(P >0.05) between the male and the female.The ratio of the female to the male was less than 1.0 in every month except in May.O.oratoria was mainly distributed in shallow waters in spawning seasons(May-July),such as the Yellow River estuary and they started to migrate to profundal zone in August and inhabited the areas from September to next March,then returned to shallow waters in April.Pearson correlation analysis indicated that environmental factor that best matched the density of O.oratoria was sea surface temperature(SST),then the salinity(Sal),the water depth(Dep),the zooplankton and other fishing catch biomass.The correlation coefficient was the lowest between the density of O.oratoria with dissolved oxygen(DO) and phytoplankton.The correlation between the average individual weight of O.oratoria with environmental factors was not significant (P >0.05),except with the Dep in August(P <0.001),September(P <0.005) and with other fishing catch biomass in July,August and next April(P <0.001).

Abstract:Two sampling transects for chlorophyll a (Chl.a) between inner bay and the mouth of bay were performed and one sampling station in kelp zone was daily sampled once every 2 hours in May and August,2014 in Sanggou Bay.The spatial distribution and diurnal variation characteristics of Chl.a were studied,and the correlations between Chl.a concentration and physical and chemical factors were analyzed by combining with the environmental factors such as temperature,salt,pH,nutrients and so on in Sanggou Bay,the change of Chl.a and its influencing factor were discussed pre-and-post-the-harvest of kelp in Sanggou Bay.(1) For the voyage survey,Chl.a concentration was significantly higher in summer than in spring in Sanggou Bay.In spring,the average Chl.a concentration in the surface layer and the bottom layer were 0.67±0.39 μg/L,0.50±0.31 μg/L,respectively,and Chl.a concentration was higher in the surface layer than in the bottom layer.The general trend of Chl.a concentration was decreasing from inner bay to the outside of the bay in surface layer in spring.In summer,the average Chl.a concentrations in the surface layer and the bottom layer were 3.39±1.53 μg/L and 3.12±1.43 μg/L,respectively,and Chl.a concentration was higher in the surface layer than in the bottom layer.The kelp area showed the highest values Chl.a concentrations and shellfish area showed the lowest values in the surface layer in summer.The kelp area and shellfish area showed the highest values Chl.a concentrations and outer site of the bay showed the lowest values in the bottom layer in summer.(2) The results of continuous observation showed that Chl.a concentration was in the range of 0.24-0.95 μg/L,and the average value were 0.70 ± 0.19 μg/L in spring in kelp zone.There was less fluctuation for Chl.a concentration day and night in spring.In summer,Chl.a concentration was in the range of 2.01-4.66 μg/L,and the average value were 3.04 ± 0.82 μg/L in kelp zone.There was greater fluctuation for Chl.a concentration day and night in summer.The Chl.a concentration in spring was significantly higher than those in summer.And the nutrient concentration,Si/P,N/P and Si/N ratio in spring were significantly lower than that in the summer.(3) There was a significantly positive correlation between Chl.a concentration and temperature or silicate concentration in the surface layer in spring.And Chl.a was significantly positive correlation with salinity in the bottom layer in summer.The distribution of Chl.a is commonly affected by temperature,silicate,salinity,marine cultures and hydrological environment pre-and-post-the-harvest of kelp in Sanggou Bay.The multi-trophic aquaculture mode of bivalves and seaweeds is important influence factor of Chl.a distribution and variation in Sanggou Bay.

Abstract:In order to know the background information of fishery resources in Zhelin Bay-Nan'ao Island marine ranching,four acoustic surveys were conducted with Simrad EK60 echosounder in different months from April 2011 to February 2012.The results showed that the average abundance density and biomass density of 21 species estimated were 2.68×10⁴ ind/km² and 0.73 t/km² respectively in April 2011.The average abundance density and biomass density of 38 species estimated were 6.49×10⁴ ind/km² and 0.71t/km² respectively in August 2011.The average abundance density and biomass density of 33 species estimated were 4.14×10⁴ ind/km²and 0.93 t/km² respectively in November 2011.The average abundance density and biomass density of 15 species estimated were 1.45×10⁴ ind/km² and 0.36 t/km² respectively in February 2012.The fish density and biomass were the highest in November and the lowest in February.The nautical area scattering coefficient (NASC) was distributed mainly in 4～8 m depth layer in April and evenly in 4-14 m depth layer in August.In November the main depth layer was similar to that in April,but the percentage in the depth layer of higher than 10 m was higher than that in April.In February NASC was distributed mainly in 4-10 m depth layer (especially 6-8 m).No significant linear relationship was observed between fisheries resources density and water depth.Fisheries resources density did not show a significant linear relationship with sea surface temperature (SST) of station monthly.There was significant linear relationship between monthly average abundance density and SST (R²=0.997 4).A linear relationship between monthly average biomass density and SST was found (R²=0.287 2).Our research confirmed that the acoustic method showed good effects in the process of marine ranching fishery resources assessment,promoting the development of acoustic technology in the research field of marine ranching and providing the realistic foundation and scientific basis for our country to further study the effect and assessment of marine ranching enhancement in the future.

Abstract:The distribution patterns of Misgurnus anguillicaudatus and Paramisgurnus dabryanus were investigated in the Yangtze River basin.Specimens of four different ploidy levels were found as diploid (2n=50),triploid (3n=75),tetraploid (4n=100) and pentaploid (5n=125).Diploids were dominant,exhibiting broadly ecological amplitude.Polypoid M.anguillicaudatus populations were concentrated in the middle reaches of the Yangtze River and its subsidiary lakes.The weight of females in both M.anguillicaudatus and P.dabryanus was significantly greater than that in males (P <0.005).However,there was no statistically significant difference between the growth traits of two species.The body length and weight of diploid M.anguillicaudatus were lower than that of triploid (P <0.005) and tetraploid (P <0.001).There was no significant difference in growth traits between triploid and tetraploid M.anguillicaudatus.Female proportion in M.anguillicaudatus populations gradually decreased from upstream to downstream,whereas in P.Dabryanus it fluctuated and no obvious trend was observed.The GLM linear regression analysis found that the body weight of M.anguillicaudatus was negatively correlated with longitude (r=-0.510),while no significant correlation was observed for P.Dabryanus (r=-0.177).This study proves the presence of P.Dabryanus and M.anguillicaudatus specimens of four different ploidy levels in natural populations in the Yangtze River basin,suggesting the need for further scientific attention and consideration of possible conservation measures.

Abstract:In order to study the reproduction of brass gudgeon (Coreius heterodon) in the upper Yangtze River before and after impoundment of the first phase of the Jinsha River Hydroelectric Project(including Xiangjiaba and Xiluodu Dam),the surveys of fish resources of early life stages were carried out in Jiangjin section from May 5 to July 10,2011-2014.Sampling was conducted continuously by conical net.The results showed that C.heterodon accounted for 14.76% of the total 8 014 eggs,the annual average fecundity of C.heterodon was 22.45×10⁷ind.From 2011 to 2014 average daily density of C.heterodon eggs were 8.41,10.57,1.32 and 3.18 ind./1 000 m³ respectively,the average daily density of 2013 and 2014 had significant difference with 2011 and 2012.The correlation between density of C.heterodon eggs and its influence factors found that C.heterodon spawning had significant negative correlation with the transparency,and the transparency of 2013 and 2014 was significantly higher than transparency of 2011 and 2012.According to egg developmental stage and flow velocity,it was inferred that Baisha to Yangshi and Rongshan to Zhaoya section were the main spawning grounds,which were contributing about 56.96% of the total C.heterodon eggs.It indicated that the Jinsha River Hydroelectric Project brought certain impacts to C.heterodon spawning in the upper reaches of Yangtze River,the operation of the first phase of the Jinsha River Hydroelectric Project should consider the environmental requirement of C.heterodon spawning,and a complete fishing ban in spawning grounds should be implernented.

Abstract:Samples of Hydractinia were collected from the South China Sea.Two new species of H.constrictura sp.nov.and H.phyllosoma sp.nov.are described in the present paper.The specific diagnosis of the two new species is as follows:Hydractinia constrictura sp.nov.Umbrella global-shaped,without apical projection; manubrium long,with a whorl slightly constriction in nearly middle part of manubrium,which is divided into two parts,with vacuolated endodermal cells scattered in upper part of manubrium and no vacuolated cells in lower part; with 4 perradial oral arms,unbranched,each termination with a single knob-shaped cluster of cnidocysts; gonads interradial on manubrium,with medusa buds; with 4 marginal tentacles,bulb global,ending in a large cnidocyst knob.Hydractinia phyllosoma sp.nov.Umbrella bell-shaped,without apical projection; without gastric peduncle,manubrium short; mouth quadrate,with 4 leaf-like lips with cnidocyst clusters; gonads interradial on manubrium,without medusa buds; 4 marginal tentacles.