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1.
Based on the simulation with SWAN wave model and data of ERA-Interim from 1979 to 2016, how the waves propagate globally and why swell pools distribute in the eastern ocean were investigated in this study. The simulation results show that waves from North Pacific and North Atlantic mainly propagate southeastward or southward and swells generated in Southern Ocean spread northeastward. The waves from high latitude regions spread along the east coast and encounter in the tropical Pacific and Atlantic to form swell fronts around equator and then turn eastward. As the weak wind field with numerous swell inflows, swell pools are generally located on the eastern side of the ocean basin, where the swell index S are greater than 0.9 calculated using ERA-20 C data for the period of 1981–2010. Another remarkable feature is that swell pools move southward and split into two parts in winter, while they move northward and merge together in summer.  相似文献   

2.
Blocking is a large-scale, mid-latitude atmospheric anticyclone that splits the westerly into two jets and has a profound effect on local and regional climates. This study examined the seasonal, interannual, and decadal variability of the Atlantic and Pacific blocking anticyclones in the Northern Hemisphere based on the National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis data between 1958 and 1999. The preferred blocking region during these forty-two years was located over the Atlantic. Most blocking anticyclones over the Atlantic occurred in spring, while most of those over the Pacific occurred in winter. Similar two-to four-year and eleven-year oscillations were found for both the Atlantic and Pacific blocks by using wavelet analysis. The dominant mode for the Pacific blocks is decadal variation, while for the Atlantic blocks the predominant one is interannual variation with a period of about three years. The frequencies of the Pacific and Atlantic blocks varied almost in phase on interannual time scales except during the period of 1965-1977, and frequencies were out of phase on decadal time scale throughout the forty-two years.  相似文献   

3.
Pyropia species grow in the intertidal zone and are cold-water adapted. To date, most of the information about the whole plastid and mitochondrial genomes(ptDNA and mtDNA) of this genus is limited to Northern Hemisphere species. Here, we report the sequencing of the ptDNA and mtDNA of the Antarctic red alga Pyropia endiviifolia using the Illumina platform. The plastid genome(195 784 bp, 33.28% GC content) contains 210 protein-coding genes, 37 tRNA genes and 6 rRNA genes. The mitochondrial genome(34 603 bp, 30.5% GC content) contains 26 protein-coding genes, 25 tRNA genes and 2 rRNA genes. Our results suggest that the organellar genomes of Py. endiviifolia have a compact organization. Although the collinearity of these genomes is conserved compared with other Pyropia species, the genome sizes show significant differences, mainly because of the different copy numbers of rDNA operons in the pt DNA and group II introns in the mtDNA. The other Pyropia species have 2–3 distinct intronic ORFs in their cox 1 genes, but Py. endiviifolia has no introns in its cox 1 gene. This has led to a smaller mtDNA than in other Pyropia species. The phylogenetic relationships within Pyropia were examined using concatenated gene sets from most of the available organellar genomes with both the maximum likelihood and Bayesian methods. The analysis revealed a sister taxa affiliation between the Antarctic species Py. endiviifolia and the North American species Py. kanakaensis.  相似文献   

4.
The complete mitochondrial cytochrome oxidase subunit II (COII) gene of Penaeinae shrimp Fenneropenaeus chinen- sis was cloned and sequenced. The gene is 688 bp in length and codes for 229 amino acids. It shows 83.2%, 87.0% and 83.8% sequence similarity to Marsupenaeus japonicus, Penaeus monodon and Farfantepenaeus notialis, respectively. The A T content of the whole gene and that at the third position of codons are 64.7% and 78.2%, respectively. The phylogenetic relationship between F. chinensis and three other species representing genera Farfanatepenaeus, Marsupenaeus and Penaeus was analyzed. Results showed that the genetic distances among the four taxa ranged from 0.144 0 to 0.200 5, exceeding those estimated with COI and partial 16S rRNA gene sequences among Marsupenaeus, Litopenaeus and Melicertus, and being therefore larger than the value among subgenera. It has been suggested that the COII gene has a faster evolutionary rate than that of the COI gene and partial 16S rRNA gene and could be used for phylogenetic analysis at genus or species level. The results of the present study indicated that Farfantepenaeus, Fenneropenaeus, Marsupenaeus and Penaeus are at a higher phylogenetic level than subgenus, which supports the opinion of the elevation of phylogenetic status of the four subgenera to genus level.  相似文献   

5.
The complete mitochondrial cytochrome oxidase subunit Ⅱ (COⅡ) gene of Penaeinae shrimp Fenneropenaeus chinensis was cloned and sequenced. The gene is 688 bp in length and codes for 229 amino acids. It shows 83.2%, 87.0% and 83.8% sequence similarity to Marsupenaeus Japonicus, Penaeus monodon and Farfantepenaeus notialis, respectively. The A+T content of the whole gene and that at the third position of codons are 64.7% and 78.2%, respectively. The phylogenetic relationship between F. chinensis and three other species representing genera Farfanatepenaeus, Marsupenaeus and Penaeus was analyzed. Results showed that the genetic distances among the four taxa ranged from 0.144 0 to 0.200 5, exceeding those estimated with COⅠ and partial 16S rRNA gene sequences among Marsupenaeus, Litopenaeus and Melicertus, and being therefore larger than the value among subgenera. It has been suggested that the COⅡ gene has a faster evolutionary rate than that of the COⅠ gene and partial 16S rRNA gene and could be used for phylogenetic analysis at genus or species level. The results of the present study indicated that Farfantepenaeus, Fenneropenaeus, Marsupenaeus and Penaeus are at a higher phylogenetic level than subgenus, which supports the opinion of the elevation of phylogenetic status of the four subgenera to genus level.  相似文献   

6.
Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.  相似文献   

7.
The global monsoon(GM) comprises two major modes, namely, the solstitial mode and equinoctial asymmetric mode.In this paper, we extend the GM domain from the tropics to the global region and name it the global spring – autumn monsoon(GSAM), which mainly indicates a spring–autumn asymmetrical precipitation pattern exhibiting annual variation. Its distribution and possible formation mechanisms are also analyzed. The GSAM domain is mainly distributed over oceans, located both in the midlatitude and tropical regions of the Pacific and Atlantic. In the GSAM domains of both the Northern and Southern Hemispheres, more precipitation occurs in local autumn than in local spring. The formation mechanisms of GSAM precipitation vary according to the different domains. GSAM precipitation in the tropical domain of the Eastern Hemisphere is influenced by the circulation differences between the onset and retreat periods of the Asian summer monsoon, while tropical cyclone activities cause precipitation over the South China Sea(SCS) and western North Pacific(WNP). GSAM precipitation in the tropical domain of the Western Hemisphere is influenced by the tropical asymmetrical circulation between the Northern and Southern Hemispheres and the variation in the intertropical convergence zone(ITCZ) driven by the intensity of the sea surface temperature cold tongues over the equatorial eastern Pacific and eastern Atlantic. GSAM precipitation in the midlatitude domain is influenced by the differences in water vapor transportation and convergence between spring and autumn. In addition, GSAM precipitation is also affected by extratropical cyclone activities.  相似文献   

8.
Virescentia guangxiensis,a new species of Virescentia from Guangxi,South China,is described and illustrated based on morphological observations and phylogenetic analysis.This species was distinguished morphologically from other species by the presence of special expansion cells with a variable shape,obovoid,spherical,pear-shaped,located in the penultimate cells of primary or secondary fascicles,rarely terminal on primary fascicles,as well as by small whorls(250-350-μm wide) and short primary fascicles(5-7 cell stories).Phylogenetic analysis of molecular data from the rbcL and COI-5 P loci supported the separation of the proposed new species from other species in the genus Virescentia.This is the first species of the order Batrachospermales reported in Guangxi and the second species of the genus Virescentia reported in China.This study expands the known species diversity and geographical distribution of fre shwater Rhodophyta in China.  相似文献   

9.
Acila divaricata (Hinds, 1843) and A. mirabilis (Adams and Reeve, 1850) are common benthic bivalves in China. A number of researchers have proposed that the latter species is a junior synonym of the former species. Because of morphological similarities, it is difficult to distinguish these two species based on visual examination only. For better understanding of their taxon-omy, the mitochondrial CO1 gene fragments of five individuals of A. divaricata from the East China Sea and six individuals of A. mirabilis from the Yellow Sea were sequenced in this study. The phylogenetic relationships of the obtained COI sequences, together with nineteen sequences of three species of the genus Nucula, were analyzed. The pairwise intra- and inter-specific distances for the CO1 sequences ranged from 0.002 to 0.017 and from 0.128 to 0.134, respectively, and no overlap was found. Phylogenetically, A. divaricata and A. mirabilis form distinct clades and cluster into a sister to all other Nucula species. The results indicated that A. di-varicata and A. mirabilis are two distinct species. The differences in the morphology and distribution between the two species were briefly discussed.  相似文献   

10.
Luidia Forbes (Paxillosida: Luidiidae) are common soft bottom sea stars with 49 described species. Because of substan- tial morphological diversity, the taxonomy of the genus is complex and hasn't been resolved definitely. In order to resolve general taxonomic issues, and determine species boundaries and phylogenetic relationships within the genus Luidia, the sequences of tyro- chrome oxidase subunit I (COI) gene from 24 specimens of Luidia, belonging to eight taxa in Chinese waters, were studied. Three sequences of two species in genus Luidia from GenBank were used to analyze the phylogenetie relationships. The molecular phy- logeny exhibited three main clades, each with strong bootstrap support: Clade A including Luidia quinaria from the Sea of Japan; Clade B including seven nominal species (L. quinaria von Martens, L. yesoensis Goto, L. ehangi Liu, Liao and Li, L. orientalis Fisher, L. avicularia Fisher, L. longispina Sladen and L. hardwicki Gray) from Chinese waters; and Clade C including L. maculata Miiller & Troschel from Chinese waters. Our molecular phylogeny results support the morphological Quinaria-Group and Alter- nata-Group assigned by D6derlein. Seven nominal species we sampled do not exhibit genetic distances that are large enough to rec- ognize them as separate species. Cryptic species may exist in 'Luidia quinaria' from the Yellow Sea and the Sea of Japan. Meaning- ful morphological characters need further investigation in Luidia.  相似文献   

11.
Two new species of Chrysogorgia Duchassaing Michelotti,1864 collected from the Caroline seamounts in the tropical Western Pacific Ocean are described.Chrysogorgia pinniformis sp.nov.belongs to Versluys' group C(Squamosae typicae) with only scales in polyp body wall and tentacles.C.pinniformis sp.nov.is characterized by large branches pinnately branched and forming multiple fans with its small branches regularly and quasi-dichotomous branched,and scales and rods present in the polyp mouth area.It is most similar to C.pinnata Cairns,2007 by the pinnate trait,but differs from the latter by its group C pattern(vs.group A,Spiculosae) and having sclerites present in the polyp mouth area(vs.absent).Chrysogorgia varians sp.nov.belongs to the Chrysogorgia group A(Spiculosae) with rods distributed in the polyp body wall and tentacles.It is characterized by warty rods and elongated scales in the tentacles,many warts and ridges on the scales,conspicuously toothed margins at the rounded ends in the pinnules,and small rods with ridge-like warts in the polyp mouth area.This species was frequent and abundant in the Caroline seamounts during our cruises and its morphological variability in growth period was obvious.The phylogenetic analyses based on mtMutS and 28 S rDNA regions supported the assignment of the new species to the genus Chrysogorgia.However,the mtMutS marker showed very limited usefulness for species delimitation and inner relationship inference of Chrysogorgia.In contrast,the 28 S rDNA showed much higher level of genetic variation,and it may be a potential barcode for this genus.In the 28 S rDNA trees,the two new species clustered together.Additionally,compilation of our data showed that 42 of 78(ca.54%) Chrysogorgia species were found in the Indo-West Pacific convergent region,indicating that this area may be a hotspot of deep-water Chrysogorgia species.  相似文献   

12.
Phaeocystis globosa is an important harmful algal bloom causative species distributing widely in temperate and tropical coastal waters in the world.The morphological,physiological,and biochemical characte ristics are different amo ng geographic strains,which can not be distinguished with nuclear ribo somal DNA markers at present.Therefore,the genetic distance and phylogeographic relationships of nuclear 28 S rDNA D1-D2 and ITS regions,and three chloroplast intergenic spacers(petN-trnS1,trnM1-psbA,and rbcS-rpl27) were analyzed and compared among 13 strains of P.globosa isolated from the Pacific Ocean and Atlantic Ocean in this study.In addition,the nucleotide polymorphisms of 28 S rDNA D1-D2,ITS,and rbcS-rpl27 regions were evaluated in two P.globosa strains.The various levels of nucleotide polymorphism were in the nuclear 28 S rDNA D1-D2 region and ITS region,but no polymorphism was in the chloroplast rbcS-rpl27 intergenic spacer.A reasonable intraspecific phylogeographic relationship was presented by rbcS-rpl27 intergenic spacer,which had the strongest distinction to geographic strains compared to those of 28 S rDNA D1-D2 and ITS regions.In the phylogenetic tree of rbcS-rpl27 intergenic spacer,the two strains from the North Sea of the Atlantic Ocean were divided firstly from the species of P.globosa,and then formed an independent clade,while the other Atlantic strains and all of Pacific strains j oined up to build the other clade.It was implied that at least two genetically distant populations of P.globosa existed in the Atlantic coastal regions.This study provided a high-resolution chloroplast marker to analyze intraspecific phylogeographic populations of P.globosa,and preliminarily clarified the genetic relationships of the Pacific and Atlantic strains of P.globosa.  相似文献   

13.
1 Introduction Dinoflagellate Alexandrium has received intensive at-tention in recent years, as it is a valuable bioactive com-pound resource and related to harmful algal bloom (HAB)which has negative impact on marine ecology systemaquiculture, human health and tourism (Hallegraeff andBolch, 1992; Smayda, 1997; Vale and Antonia de MSampayo, 2001). However, not all of the species in genusAlexandrium produce toxin (Wendy et al., 2001), so rapididentification and clarification of the phyloge…  相似文献   

14.
The genus Cylindrotheca consists of a small group of marine diatoms with a few species described. Eleven isolates of diatoms identified as Cylindrotheca closterium morphologically were obtained from Jiaozhou Bay with their nuclear-encoded small-subunit ribosomal RNA (SSU rDNA) and chloroplast-encoded rbcL gene sequences determined in this study. Interestingly, very high sequence divergences of SSU rDNA and rbcL gene were found among these isolates, and numerous nucleotide variation of rbcL gene caused relatively few variation of deduced amino acid sequence. Phylogenetic analyses based on SSU rDNA and rbcL gene, respectively, grouped the isolates into 6 clades. Phylogenetic tree of SSU rDNA placed all the Cylindrotheca isolates together, separating them into two lineages clearly. LineageⅠ was composed of the eleven C. closterium isolates obtained in this study together with another C. closterium isolate, but some clades were not well supported. LineageⅠwas contained two C. closterium isolates and one C. fusiformis isolate. Phylogenetic analysis of rbcL gene also separated the Cylindrotheca isolates into two well-defined lineages. The eleven C. closterium isolates formed a lineage and all clades were supported strongly. Statistical comparisons of SSU rDNA indicated that the average distance within lineageⅠwas significantly higher than that of other microalgae species (P 〈0.01). These results suggested the existence of cryptic species within C. closterium.  相似文献   

15.
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) plays important roles in various cellular processes. A cytosolic GAPDH encoding gene (gpd) of Gracilaria/Gracilariopsis lemaneiformis was cloned and characterized. Deduced amino acid sequence of the enzyme of G. lemaneiformis had high homology with those of seven red algae. The 5'-untranslated regions of the GAPDHs encoding genes of these red algae varied greatly. GAPDHs of these red algae shared the highly conserved glyceraldehyde 3-phosphate dehydrogenase active site ASCTTNCL. However, such active site of Cyanidium caldarium was different from those of the other six algae at the last two residues (CL to LF), thus the spatial structure of its GAPDH active center may be different from those of the other six. Phylogenetic analysis indicated that GAPDH of G. lemaneiformis might have undergone an evolution similar to those of Porphyra yezoensis, Chondrus crispus, and Gracilaria verrucosa. C. caldarium had a closer evolutionary relationship with Cyanidioschyzon merolae than with Cyanidium sp. Virtual Northern blot analysis revealed that gpd of G. lemaneiformis expressed constitutively, which suggested that it might be house-keeping and could be adapted as an inner control in gene expression analysis of G. lemaneiformis.  相似文献   

16.
17.
The 5.8S ribosomal DNA sequences (5.8S rDNA) and their flanking regions, internal transcribed spacer 1 and spacer 2 (ITS1 and ITS2) of three new isolates in genus Alexandrium (Alexandrium sp. qd1, Alexandrium sp. qd2, Alexandrium sp. gz) from China were amplified, sequenced, and subjected to phylogenetic analysis. Alexandrium sp. gz and Alexandrium sp. qd1 were grouped with high bootstrap values with four strains/species, i.e., A. catenella South Korea strain, A. catenella Japan strain, and two from China, Alexandrium sp. AC03 and Alexandrium sp. AN01 being proposed to be A. catenalla in a previous study. Then Alexandrium sp. gz and Alexandrium sp. qd1 were identified as Alexandrium catenella. As A. catenella was isolated from Qingdao and Guangzhou sea areas, it supposedly distributed at least in these two areas and was genetically different. Alexandrium sp. qd2 differed greatly from species in Alexandrium. It clustered with Symbiodinium californium, Symbiodinium sp. G15 and Gymnodinium sp. Zhao 01 with 100% bootstrap value; so Alexandrium sp. qd2 affiliates to genus Symbiodinium, and is probably a free-living Symbiodinium species.  相似文献   

18.
The marine green alga Chaetomorpha valida fouls aquaculture ponds along the coastal cities of Dalian and Rongcheng, China. Unialgal cultures were observed under a microscope to determine the developmental morphological characters of C. valida. Results reveal that gametophytic filaments often produce lateral branches under laboratory culture conditions, suggesting an atypical heteromorphic life cycle of C. valida between unbranched sporophytes and branched gametophytes, which differs from typical isomorphic alternation of Chaetomorpha species. The shape of the basal attachment cell, an important taxonomic character within the genus, was found variable depending on environmental conditions. The 18S rDNA and 28S rDNA regions were used to explore the phylogenetic affinity of the taxa. Inferred trees from 18S rDNA sequences revealed a close relationship between C. valida and Chaetomorpha moniligera. These results would enrich information in general biology and morphological plasticity of C. valida and provided a basis for future identification of green tide forming algae.  相似文献   

19.
The genus Munidopsis has high biodiversity in seamount habitats.In this study,two new Munidopsis species,Munidopsis ahyongi sp.nov.and Munidopsis carolinensis sp.nov.from the Caroline Ridge in the tropical western Pacific Ocean were described.M.ahyongi sp.nov.is very similar to a group of species in the M.serricornis complex,but can be readily distinguished from the related species in having the oblique posterior orbital margins,2 spines on the lateral carapace margin,and a relatively longer rostral median spine.M.carolinensis sp.nov.is different from two related species primarily in having oblique frontal margins,blunt outer orbital angles,straight lateral margins of the rostrum,scale-like rugae on sternites 5-7,and less spinose pereopod 1(chelipeds,P1) merus and carpus.Aside from the morphological comparisons,DNA barcode analysis and phylogenetic analysis based on the cytochrome c oxidase subunit I gene(COI) were employed for the identification of these new species.  相似文献   

20.
Three deep-sea black corals belonging to the family Schizopathidae,are reported from two seamounts on the Caroline Ridge in the tropical Western Pacific:Umbellapathes parva sp.nov.with depth of 1 488-1 766 m,Telopathes cf.magna MacIsaac Best,2013 with depth of 937-1 016 m,and Stauropathes cf.punctata(Roule,1905) with depth of 942-1 353 m.The latter two species are the first records in the Western Pacific Ocean.U.parva sp.nov.is characterized by monopodial corallum,relatively long unpinnulated stalk with complex pinnulated branche s developing from the lowermost primary pinnules and small spine s.It differs from two known congeners by much smaller spine s and the present of secondary pinnules.T.cf.magna MacIsaac Best,2013 has sparsely branched corallum,relatively long and simple pinnules arranged in subopposite or alternate pairs.S.cf.punctata(Roule,1905) is characterized by the corallum with almost planar pinnulated branches,and pinnules arranged in subopposite pairs.Our results indicate that the corallum size and shape are variable in conspecific specimens particularly those at different growth stages.By contrast,the size of the polypar spines as well as the abpolypar spines have little variation and can be served as a main differing feature for schizopathid species.The phylogenetic analyses using nuclear internal transcribed spacer region(spanning partial 18 S rDNA,ITS 1,5.8 S,ITS2,and partial 28 S rDNA) and two mitochondrial fragments cox3-IGR-coxl(COI) and trnW-IGR-nad2(NAD2) showed Telopathes,Stau ropathes,and Bathypathes had close relationships,and Umbellapathes formed a sister clade with Alternatipathes.  相似文献   

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