Genetic diversity can reflect the origin and evolution of species. It can also inform the practices of genetic conservation, breeding and genetic improvement, even stabilization of marine ecosystem. In the past two decades, accumulating studies have focused on the genetic diversity of major marine fish and shellfish in China. Here we summarize the achievements of this area and its application to taxonomy, germplasm identification, phylogenetic evolutionary biology, analysis of population genetic structure, genetic breeding and so on. We hope to provide new insights into research on genetic diversity of marine animals, and promote the healthy development of the aquaculture industry in order to achieve the management and sustainable use of marine animals.

This paper documents the morphology, taxonomy and diversity of living coccolithophores in Chinese sea waters (CSW). Totally, 97 species have been recorded, belonging to 4 orders, 11 families, and 44 genera. Syracosphaera, including 20 species, is the most abundant living coccolithophores genus in CSW. We also list five new record species in this paper. They are Cyrtosphaera lecaliae, Syracosphaera histrica, Corisphaera strigilis, Pontosphaera discopora and Braarudosphaera bigelowii. Meanwhile, we also describe 19 species (include six species indeterminate) of living coccolithophores founded in CSW, based on scanning electron microscopy (SEM) or polarizing microscope observations. The identification key for common living coccolithophores species in CSW is also presented.

Efforts have been made by scientists studying on the taxonomy, biogeography and biodiversity in China seas since 1950, the establishment of Qingdao Marine Biological Laboratory, Chinese Academy of Sciences (CAS). Over 1,000 papers and 200 volumes of monographs have been published, of which more than 47 volumes are Fauna Sinica ― Invertebrata (27 volumes on marine biota), 11 volumes of Fauna Sinica ― Vertebrata are on fishes, and 8 volumes are Flora Algarum Marinarum Sinicarum. Results of studies on biodiversity in whole China seas were summarized in Marine Species and Their Distributions in China’s Seas’ (1994) and Checklist of Marine Biota of China Seas (2008). In the latter volume, new taxonomic results up to 2007 were added, and a total of 22,629 marine species were recorded, with an increase of 5,118 species compared with those reported in 1994. So far, the biodiversity of China seas is high. The results of “Shelf Environment and Bio-resources Survey 1997-2000” and those of “Endangered Species Assessment Project” (2000-2004) published in China Species Red List vols.1, 3, 2A, 2B ( 2004, 2005 and 2009) revealed that under the impacts of global climate change and anthropogenic activities, the biodiversity and bio-resources have seriously declined, the number of endangered species increased, and some major populations collapsed. China joined the World Marine Biodiversity Project “Census of Marine Life” (CoML) in 2004. In the project “Census of Marine Zooplankton”, ecosystem dynamics and biodiversity characteristics had been investigated; and in a survey cruise from Arctic to Antarctic through Equator, 2000 zooplankton samples were taken by R/V “Science I” of Institute of Oceanology, CAS, and 260 DNA barcoding data have been obtained. For the CoML “NRIC: Synthesis Program”, the China Collection Report entitled “Status of marine biodiversity study in China seas” had been drafted and submitted to PLoS ONE for publication, the progress of China’s marine biodiversity and biogeography studies has been reviewed by the present author. To strengthen the conservation of biodiversity and endangered species, 33+21 National Marine Nature Reserves and 7 National Marine Parks have been established up to date. Problems in marine biodiversity study and conservation in China seas are discussed and the following suggestions are put forward: (1) To strengthen the collection of materials (specimens) for marine biodiversity study, a biodiversity background value survey and deep sea collection cruises should be carried out to discover new species and reveal the past, present, and to predict the future trends of major species and biological communities; (2) Carrying on biodiversity monitoring survey in various habitats around the country, to understand the processes and mechanisms of global climate change and human activities impacting biodiversity; (3) Strengthening basic research on change in marine biodiversity, particular the assessment and conservation of biodiversity and endangered species for sustainable development; (4) Minimizing the disparity between the study and conservation of marine and terrestrial (including freshwater) biodiversities, and effective management; and (5) Training young scientists, particularly taxonomists to study different biotic groups systematically.

China has among the largest latitudinal ranges of any country on Earth. Environmental factors such as diverse climate, hydrology and topography jointly determine levels of marine environmental diversity and therefore patterns in zooplankton diversity in China seas. Studies of zooplankton diversity in China progressed through different stages from a main focus on species taxonomy, diversity of distribution pattern, to a focus on environment influences on the ecological group, and finally a focus on zooplankton adaptations to various environments. Topography, water mass, and monsoon occurrence were determined to be three determinate factors of marine environmental patterns in China seas. Based on this knowledge, studies on the influence of different environmental factors on zooplankton diversity have attracted more interest. The absence of consistent research protocols has led to a global bottleneck in research on environmental adaptations of zooplankton. Past difficulties in estimating ecological parameters such as the optimum temperature and salinities of species’ distributions have been alleviated with improved field data and statistical methods. Many mathematical methods such as the yield-density model, levenberg-marquardt curve fitting, mean value theorem, and Romberg integral calculation have also been widely applied. These methods have proven useful for delineating and differentiating ecological groups as well as elucidating the factors contributing to zooplankton diversity. Future studies on zooplankton diversity should attack these questions from multiple angles including studies in different habitats, at various spatial and temporal scales, and of different taxonomic groups, biomass size spectra, and ecological groups. Finally, we predict that applied studies will become an increasingly significant field within zooplankton diversity research.

The progress on the studies of marine macrobenthic biodiversity from Chinese waters with a focus on the Yellow Sea is summarized in the present paper, with discussions of achievements in the fields of species composition, individual consistency, biomass, biodiversity, secondary productivity, macrobenthic community energy levels, and the introductions of research methods, impacts of environmental change and pollution. To date, Jiaozhou Bay, Changjiang Estuary, and the Fujian and Zhejiang coastal zones are the most intensively studied regions. The seminal research projects on macrobenthic ecology and biodiversity within the study region are also listed. In conclusion of the studies of macrobenthic ecology and biodiversity in China seas, the macrobenthic fauna from the Bohai Bay is the most simple. A total of 413 macrobenthic species have been found in this gulf, the common or dominant species are usually the hypothermal, euryhalinous warm water species; the annual mean biomass is 19.83 g/m², the Mollusca is the main contributing group to the biomass; the annual mean density is 474 inds./m², the Polychaeta and Mollusca are the two main contributing groups to the density. In the Yellow Sea, 853 macrobenthic species have been found. The common or dominant species are stenohaline warm water species; the annual mean biomass from the northern Yellow Sea is 99.66 g/m², the Echinodermata is the main contributing group to the biomass, the annual mean biomass from the southern Yellow Sea is 27.69 g/m², which is much lower than that from the northern Yellow Sea, the Polychaeta is the main contributor; the annual mean density from the northern Yellow Sea is 2,017.40 inds./m², that from the southern Yellow Sea is only 88.67 inds./m². In fact, the mean density and biomass from the northern Yellow Sea is much higher than those from other areas in China seas; the annual mean secondary productivity from the southern Yellow Sea is 4.98 g(AFDW)/m², the two high areas of secondary productivity are located in the two sides of the Yellow Sea Cold Water Mass. In the East China Sea, there have been found 1,300 macrobenthic species, in which, 45 are common or dominant ones; the differences among the seasonal mean biomasses are indistinct, usually spring>winter>summer>autumn; the annual mean biomasses from area off Zhejiang Province(28.22 g/m²)>Changjiang Estuary area (15.55 g/m²) >Taiwan Strait (8.98 g/m ²), the annual mean density from the East China Sea is 164 inds./m², the trend of the density is higher and higher from north to south areas. In the South China Sea, 1,661 macrobenthic species, distinctly more than those from the Bohai Gulf, Yellow Sea and East China Sea, part of dominant species are the same as those from the East China Sea, very different from those from the Bohai Gulf and the Yellow Sea; the annual mean biomass is 20.06 g/m², usually the seasonal biomasses are spring>winter>autumn> summer, the Mollusca and Echinodermata are the two main contributing groups to the biomass; the annual mean density is 198 ind./m², usually the seasonal densities are summer>spring>winter>autumn, the Polychaeta is the main contributor to the density. The main themes of this research are ever-increasing impacts from human activities and global climate change, and the pressing need for conservation of marine biological resources. The conservation and sustained utilization of marine biological resources need the understanding of the changing mechanisms of marine macrobenthic biodiversity based on the approach of long-term change of marine environment.

Based on records of fishes from the Yellow Sea found in literatures, databases and our own investigations from the 1950’s to 2011, we summarize the species composition and faunal characteristics of fishes in the region. A total of 113 families and 321 species have been recorded in the Yellow Sea. Among them, 139 are warm temperate species, 107 are warm water species, 70 are cold temperate species and only 5 are cold water species. Based on records from the literatures and fish databases, the habitat types of Yellow Sea fish species can be grouped as follows: 193 continental shelf demersal fishes, 41 continental shelf reef-associated fishes, 34 continental shelf pelagic-neritic fishes, 29 continental shelf benthopelagic fishes, 15 oceanic pelagic fishes and 9 oceanic bathydemersal fishes. Since the 1980’s, fishery resources in the Yellow Sea have changed in terms of both species composition and biomass. Engraulis japonicus has become a very dominant species with a high current CUPE, whereas it was relatively low before. Some small and less-valuable species, such as Johnius belengerii, Liparis chefuensis, Amblychaeturichthys hexanema, Enedrias fangi, Ammodytes personatus, have also become dominant species in Yellow Sea fisheries. On the other hand, many traditionally and economically important fishes, such as Larimichthys polyactis, Gadus macrocephalus, Clupea pallasi, Scomberomorus niphonius, Scomber japonicus, Pampus echinogaster etc., have lost dominance and now exhibit a low CPUE. These results suggest that fishery resources in the Yellow Sea have been over-exploited, and that more attention should be paid to the effective management of this resource and its ecological protection.

The western Pacific region has been operating as a centre for the origin of marine biodiversity: the richest diversity of many marine taxa was found in these waters. Therefore, biodiversity research and conservation efforts in this area are necessary in order to promote the integrative and international management of this resource. The present work is a compilation of numbers of all the families, genera and species of major taxa of zooplankton known in the western Pacific Ocean(106°-150°E, 0°-44°N). In all, 2,658 zooplanktonic species (including subspecies) belonging to 206 families and 675 genera have been recorded from taxonomic identifications and literature, 99 families, 251 genera and 697 species belong to the Medusozoa, 12 families, 22 genera and 59 species to the Ctenophora, 14 families, 35 genera and 86 species to the pelagic Molluscs (Pteropoda and Heteropoda), 8 families, 89 genera and 416 species to the Ostracoda, 51 families, 156 genera and 908 species to the Copepoda, 4 families, 58 genera and 202 species to the Mysidcea, 2 families, 8 genera and 56 species to the Euphausiacea, 8 families, 22 genera and 105 species to the Decapoda, 5 families, 8 genera and 48 species to the Chaetognatha, 5 families, 26 genera and 81 species to the Tunicata.

Coral reefs contain the highest biodiversity ecosystem on Earth. In order to improve our understanding of the biodiversity and zooplankton communities, zooplankton was sampled using vertical trawls with 169 μm and 505 μm planktonic nets at 10 stations (5 within lagoon and 5 on reef flat) and one continuous observatory station from the 5 ^th to the 15^th of May, 2004 in the Zhubi Atoll of the Nansha Islands. A total of 96 species and 17 groups of planktonic larvae were identified, among which the greatest species number was the copepods with 65 species, followed by the planktonic larvae. The average abundance of zooplankton based on the data from 169 μm planktonic net was 926.0 ± 1,155.8 inds./m³. Decreasingly dominant groups included copepods, tunicates and larvae, while dominant species included Centropages orsinii, Acartia shuzheni, Oikopleura longicauda, O. fusifornis and Gastropoda veliger. Zooplankton community structure differed between the lagoon area and reef flat. The lagoon was characterized by high species number and abundance, a prominence of dominant species and low in species evenness indices, while the reef flat showed a more even community, likely due to relatively high levels of spatial heterogeneity in coral reefs. Diurnal variations of zooplankton were obvious that species richness and average abundance at nighttime were 4.6 and 46.2 times that of the daytime values on the reef flat, respectively. Holoplankton dominated communities both in terms of richness and were either transported from oceanic waters outside the atoll or were associated with the reef-associated itself. Both meso- and micro-zooplankton played an important role in species richness and abundance in the coral reef.

With vast sea areas, long coastline and complex environmental conditions, the China seas contain various habitats for bivalves. The diversity characteristics of some typical habitats can reflect the molluscan fauna of China seas. Based on our years of work and records from malacologists home and abroad, the bivalve diversity, habitats and ecological habits in different environments are described, and the distribution characters in different sea areas are analysed. Due to the effects of coastal water, Yellow Sea Cold Water Mass and Yellow Sea Warm Current, faunal elements in Yellow Sea are the most complex. Most of the species in East China Sea are subtropical elements, and the warm water species increases with the decrease of latitude and distance from coast, because of the hydrological characters of Kuroshio Warm Current and Taiwan Warm Current. The south part of the South China Sea is close to the equator and the north part is subtropical, with many special habitats, such as, coral reefs, mangroves and sea grass beds. The biodiversity is the highest among China seas. Up to now, a total of 1,104 species of bivalves belonging to 393 genera 77 families are reported. The number of species occurred in Bohai Sea, Yellow Sea, East China Sea and South China Sea are 87, 175, 337 and 822 respectively.

Using macrofaunal data collected at five transects in Shenzhen Bay intertidal zone between 1995 and 2010, we analyzed density, species diversity index (H'), richness index (d) and multivariate marine biotic index (M-AMBI). We found spatial differences in macrofaunal species number, species diversity, richness index and M-AMBI. Namely, the closer to Shenzhen River a sampling transect was located, the lower the macrofaunal species number, species diversity, richness index and multivariate marine biotic index. The most obvious spatial difference in terms of macrofaunal community structure was that densities of the larger-bodied species Dendronereis pinnaticirris and Neanthes glandicincta were low, while the densities of smaller and short-lived species including Capitella capitata and oligochaete animal were high at transect close to Shenzhen River. Abundance biomass comparison (ABC method) validated the spatial difference. Decreasing distance to the Shenzhen River was also related to increased levels of organic matter. We surmise that the spatial differences we observed were related to industrial, aquacultural and municipal wastes entering the Shenzhen River associated with increasing regional population and development during the study period. Yearly and seasonal variations of macrofaunal species number, density, species diversity index, richness index and multivariate marine biotic index were inconsistent, and we found no obvious trends.

Coral surveys at Xisha Islands in the South China Sea in 2006 recorded 188 species and subspecies in 45 genera and 13 families. Combined with literature records, a total of 204 species of scleratinian. corals in 50 genera and 13 families are known from the Xisha Islands, a list which includes almost all known species in China as well as 62 new record species. The scleratinian fauna was dominated by branching species which are generally rapidly growing corals. Various diversity indices revealed that the reefs at Huaguang, Treasure Island and Yongxing Island exhibited the highest species diversity. With increasing attention paid to coral reef conservation, it is desirable to establish key protected areas based on the characteristics of scleractinian species diversity and distribution.

This paper summarizes all the reef fishes collected in Tungsha (Pratas) Island and Taiping Island (Nansha or Spratly) in the South China Sea, along with records of these two islands from literatures and databases since 1975. A total number of 73 families and 652 species in Tungsha Island as well as 56 families and 466 species in Taiping Island were obtained, with 76 families and 759 species found in both Islands. The reason why the species number in Taiping is less than that of Tungsha is because the reef area of Taiping is much smaller and fewer surveys were conducted. Based on the analysis of zoogeographical distribution range of each species, we found that almost all the species recorded in the two islands are widely distributed species in Indo-Pacific, Indo-western Pacific and western Pacific. Only one species, Chrysiptera chrysocephala, was found only in the South China Sea. This result infers that the fish fauna in the South China Sea can fully exchange with that in the surrounding waters or the Coral Triangle region, and any geographical isolation or speciation phenomenon is not discernible. In addition, although the Sørensen similarity index between Taiping and Tungsha reached 85.69%, a total of 240 species is absent from either Taiping or Tungsha, i.e. 165 species were recorded in both Tungsha and Taiwan but absent at Taiping, and 75 species were recorded in both Taiping and Taiwan but absent at Tungsha. Furthermore, most of the 21 and 20 species which were recorded only in Taiping and Tungsha, respectively, are hard-to-survey rare species. We speculate that our surveys in both islands are rather insufficient. If the investigation could be more intensive and longer-term, the similarity of fish faunas between these two islands will be even higher.

The resting cyst plays an important role in the life cycle of certain dinoflagellates. Cyst formation is of great significance to populations in terms of perseverance and dispersal. Dinoflagellates producing cysts spend much more time in the sediment than in the water column, and studies on cysts help to uncover dinoflagellate diversity. Cyst diversity and abundance within sediments can reflect the history of overlying dinoflagellates and environmental conditions, and thus serve as a historical record of phytoplankton community and environmental changes. By analyzing the amount and relative proportion of different cysts, the paleo-oceanographical environment can be reconstructed. Here we review recent progress in the study of dinoflagellate cysts within China’s seas. We point out the insufficiency of identifying dinoflagellate cysts based solely on morphological characters, and stress the need to combine results with results of germination experiment. We integrated literature data and provide a checklist of dinoflagellate cyst in China seas: a total of 67 species from 25 genera are listed. Their biological and paleontological names as well as distributional ranges are given. The genus Protoperidinium is most rich with 18 species, followed by Scrippsiella (9), Gonyaulax (7), and Alexandrium (5); other genera contain 1-3 species each. In the present studies in China, species identification based mainly on morphological observations likely result in uncertain taxonomical classification of some species. Finally we discussed fruitful directions for further studies.

To better understand mechanisms of plankton community response to environmental change, the plankton community structure and diversity were investigated at nine stations near Sanya city between October 26 and September 10, 2006. A total of 130 phytoplankton taxa belonging to 61 genera and 4 classes, 76 zooplankton species belonging to 9 groups, were identified in the present study. Among the phytoplankton, 101 species in 48 genera belonged to Bacillariophyta, 25 species in 10 genera belonged to Pyrrophyta, 3 species in 2 genera belonged to Cyanophyta, and 1 species belonged to Chrysophyta. The genus Chaetoceros had most abundant species, followed by Rhizosolenia. Density of phytoplankton ranged between 348-11,320 cell/L (average 3,247 cell/L) at the nine stations. Bacillariophyta dominated phytoplankton assemblages with an average of 3,230 cell/L, comprising 99.5% of the total phytoplankton abundance. As for zooplankton, species of Copepods were most abundant (29), followed by Medusae (17), Pelagic larvae (10), Chaetognaths (7), Tunicata (6), Gastropoda (4), Decapoda (1), Polychaeta (1) and Ostracoda (1). The first three were the dominant groups, contributing 28.5%, 27.7% and 13.6% of total zooplankton density, respectively. The density of zooplankton was 43-190 ind./m³ (average 114 ind./m³). The Shannon-Wiener diversity index and Pielou’s evenness index were 3.98 and 0.70 for the phytoplankton community, and 4.37 and 0.87 for the zooplankton community, respectively. Among nine stations, Luhuitou and Dadonghai had high density but low species diversity of phytoplankton. There were more species of reef-building corals and higher live coral coverage in the stations with higher plankton diversity.

The marine microbenthos is composed of prokaryotic bacteria and archaea, and eukaryotic microalgae and protozoa that live in or on bottom sediments. Compared to those in pelagic systems, marine benthic habitats, particularly those in deep-sea, are highly heterogeneous and harbor diverse microbenthic communities whose abundance and productivity exceed those of the water column by one to several orders of magnitude in some cases. The marine microbenthos constitutes an essential component of marine biodiversity and ecosystems, particularly in marine biogeochemical cycles. Our understanding of microbial diversity and distribution within the benthos is greatly hampered by the lack of taxonomical data and undersampling. Estimation based on theories and statistics have yielded varied pictures of microbial diversity. Molecular evidence has also provided new insights into the microbial world. The present paper summarizes literature dealing with the biodiversity and geographical distribution of marine microbenthos, from bacteria to eukaryotic algae and protozoa. Striking progress has been made towards understanding the community structure, diversity and molecular phylogeny of benthic bacteria, while most benthic protozoa, with the exception of marine interstitial ciliates, are still an understudied group, largely due to taxonomic impediments and methodological limitations. Thus far, most research focuses on molecular and species diversity within marine microbenthos, while little research concerns habitat diversity. Our review highlights the need for more comprehensive investigation of the diversity, distribution and ecological role of the marine microbenthos.

A species checklist of contemporary living tintinnid (Ciliophora, Spirotrichea, Tintinnida) ciliates around the world was compiled according to references since Kofoid and Campbell (1929). A total of 954 species belonging to 69 genera and 15 families were listed in marine and fresh waters all over the world. Among them, 925 species live in marine habitats and 29 species live in fresh water biotopes. Tintinnopsis is the most abundant genus. It has 137 species, of which 118 live in marine habitats. In China, 164 species including 20 species in fresh waters, belonging to 36 genera and 13 families, have been recorded. Of them, 144 species live in the seas. There were 9 species, namely Codonella cratera, Stenosemella lacustris, Tintinnidium ephemeridum,Tintinnidium ranunculi, Tintinnidium semiciliatum, Tintinnopsis fusiformis, Tintinnopsis illinoisensis, Tintinnopsis ovalis, and Tintinnopsis cylindrata, living in fresh waters in the list were not recorded in China. In the list, Chinese species name were given, of which159 were adopted from the present literature. We also revised Chinese name of Salpingella decurtata, Codonellopsis glacialisand several species of genera Tintinnopsis and Leprotintinnus.

Estuaries are among the most productive and dynamic aquatic ecosystems on earth, due to the mixing of fresh and salt waters and significant recycling of nutrients and organic matters. Sitting in a transi- tional zone, bacterial communities in an estuary typically harbor representatives of both freshwater and ma- rine groups: Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Cyanobacteria (Synechococcus), Bacteroidetes, Actinobacteria, and Verrucomicrobia. In addition, estuaries such as Chesapeake Bay also contain their own unique bacterial signatures including the SAR11 group, Roseobacter, SAR86, and Actino- bacteria subclades, suggesting the ecological adaptation of organisms endemic to the Bay or perhaps, to large temperate estuaries in general. Relative to spatial variations, remarkable seasonal shifts and recurring annual patterns were identified in Chesapeake Bay bacterial communities. Besides water residence time and bacterial growth rate, many other factors are potential driving forces for the microbial diversity and bacterial population dynamics we observed. Temporal variations in bacterial communities were best explained by change in chlorophyll a (Chl a) and water temperature, while other factors such as dissolved oxygen, ammonia, nitrite and nitrate, and viral abundance also appeared to contribute to seasonal succession. Recently, the applications of community-based genomics and postgenomics (transcriptomics and proteomics) have allowed us to study the comprehensive gene diversity and gene expression directly from natural microbial communities. We predict that further studies and analyses of these genes and proteins will deliver new discoveries regarding the composition and function of microbial communities in aquatic environments.

The family Ellobiidae is a special group of primitive pulmonate molluscs that live in tropical and subtropical areas, mainly in high tidal and supratidal zones of coastal areas. Ellobiids occur widely and abundantly in mangrove areas. Of the 240 species known globally, over half of them have been recorded in mangrove habitats. In this paper, we summarize species of halophilic ellobiids in China and the relationship between ellobiids and mangroves. We discuss the achievements of mangrove ellobiids studies in the fields of species composition, distribution, ecological function and behavior. We also report a complete list of the ellobiid species from mangroves and their distribution within mainland China, including 21 newly recorded species. It is implied that this group is very sensitive to environmental changes and human disturbances, therefore it can be used as a bio-indicator for sea dike construction, which is an important proposed research topic in future.

Herein, we introduce, summarize, and analyze the taxonomy, species composition, distributional characteristics, major research results, and current status of Chinese marine macroalgae with updated references. The China sea flora can be divided into four sub-floras, viz. the western region of the Yellow Sea, the western region of the East China Sea, and the northern and southern regions of the South China Sea. More than 1,277 species of marine macroalgae were recorded along the China seas coast, including 161 in Cyanophyta, 607 in Rhodophyta, 298 in Phaeophyta and 211 in Chlorophyta, respectively. We briefly introduce the overall distribution, vertical distribution and spatial-temporal changes of marine algae located within the littoral area. We analyze some problems which limit the study of Chinese marine macroalgae, including difficulties in sampling and habitat deterioration. Moreover, classic taxonomy has not been attached enough importance and has not been updated with molecular techniques, and lack of talents.

As the main components of marine biota, zooplankton play vital roles in the marine biodiversity, trophic relationships and ecosystem dynamics. However, morphological identification of zooplankton is time-consuming and even impossible for some taxa, especially for pelagic larvae. Diversity of marine zooplankton is believed to be underestimated. DNA Barcodes (short DNA sequences for species recognition and discrimination) provide powerful tools for rapid species identification and are quickly applied in marine zooplankton ecological researches. Here we give a general introduction on the concept, advantages, and limitations of DNA barcoding. We review the multiple applications of DNA barcodes (mainly focused on the mitochondrial cytochrome c oxidase subunit I (mtCOI) gene) in the marine zooplankton ecological researches, which include rapid species identification, cryptic species reveal, trophic relationship analysis, invasive species monitoring, historical range expansion, population genetic and biogeographic analysis. We anticipate that DNA barcoding techniques will be increasingly used by marine ecologists. With the DNA barcode reference libraries completing and new high-throughput tools such as next generation sequencing developing, DNA barcoding will provides more information that, not only for species identification and discovery, but also help to improve our understanding of zooplankton biodiversity and their functions in marine ecosystems.

The echinoderms are important components of macrobenthos. In order to understand the diversity of echinoderm fauna of China seas, the characteristics of their fauna are analysed according to the species composition and distribution patterns. The effects of marine environmental factors such as temperature, currents and water mass to the distribution of echinoderms are also discussed. The results showed that the echinoderm fauna of China seas now comprise 591 species in 5 classes: 44 crinoids, 86 starfish, 93 sea urchins, 147 sea cucumbers, and 221 ophiuroids. There is significant difference in species composition of echinoderms between the Yellow Sea, the East China Sea and the South China Sea. Only 59 species are distributed in the Yellow Sea; more than 200 species are distributed in the East China Sea; the number of species known from the South China Sea is about 450. The distributional characteristic of species shows that the species number and the warm water species are on the increase from the north toward the south. It is worth mentioning that the cold water species dominated by the ophiuroids Ophiura sarsii vadicola and Ophiopholis mirabilis are found in large quantities in the deeper part of the Yellow Sea due to the existence of the Yellow Sea Cold water mass (where the summer bottom water temperature is not higher than 4-8℃ in the north, and 8-12℃ in the south) in the summer. Consequently, the present authors are of the opinion that the echinoderm fauna of the Yellow Sea should be considered as a constituent portion of the temperate fauna, being a subregion belonging to North Pacific Temperate Biotic Region. Of the 591 species of echinoderms, 34 species are elements of North temperate fauna (sharing 5.8%); 557 species are warm water species (sharing 94.2%), most species of which are widely distributed in Indo-west Pacific region. Generally speaking, the echinoderm fauna of China Seas is predominantly warm water elements.