Molecular analysis of Sargassum from the northern China seas

The species-level taxonomy of the marine brown algal genus Sargassum is problematic. To resolve some of these systematic issues in the northern China seas, a molecular analysis of Sargassum species was carried out using ITS-2, cox3, and rbcL DNA sequences. Phylogenetic analyses confirmed eight species, including: S. confusum, S. fusiforme, S. hemiphyllum var. chinense, S. horneri, S. muticum, S. siliquastrum, S. thunbergii, and S. vachellianum. The previously described S. shandongense and S. qingdaoense, endemic to the Shandong Peninsula, are shown to be synonymous with S. vachellianum. Seven species previously described from the East China Sea were not observed, and require further investigation.

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Detrital Zircon U-Pb Ages in the East China Seas: Implications for Provenance Analysis and Sediment Budgeting

Minerals ◽

10.3390/min10050398 ◽

2020 ◽

Vol 10 (5) ◽

pp. 398

Author(s):

Xiangtong Huang ◽

Jiaze Song ◽

Wei Yue ◽

Zhongbo Wang ◽

Xi Mei ◽

...

Keyword(s):

East China Sea ◽

Yellow Sea ◽

Bohai Sea ◽

East China ◽

China Seas ◽

Provenance Analysis ◽

The East China Sea ◽

The Bohai Sea ◽

China Sea ◽

Source Regions

Linking marine sinks to potential terrestrial sources is one of most intriguing but challenging aspects of sediment source-to-sink studies. In this study, we analyzed 23 zircon samples (3271 filtered best ages) from surface sediments of the east China seas (ECSs) that cover a large portion of the Bohai Sea, Yellow Sea, East China Sea to part of the northeastern South China Sea. The results of U-Pb age distributions exhibit variable signatures in different seas. The Bohai Sea is characterized by 4 age populations at 203–286 Ma, 383–481 Ma, 1830–1940 Ma and 2480–2548 Ma, whereas the southern Yellow Sea and the East China Sea are featured by 5 age populations at 176–223 Ma, 383–481 Ma, 732–830 Ma, 1830–1940 Ma and 2480–2548 Ma. We propose that the presence or absence of the population of 732–830 Ma in the Yangtze Craton (YC) and the North China Craton (NCC) is a possible geochronological signature to distinguish zircon grains derived from the two source regions. Furthermore, on the basis of multidimensional scaling (MDS), U-Pb ages in the sediments of the Bohai Sea, East China Sea and the Taiwan Strait could be correspondently linked to those of the Yellow River, the Yangtze River and Taiwan rivers. The good linkages support the view that U-Pb age distributions of detrital zircons in the margin seas are mainly controlled by fluvial discharges, and ultimately, by the tectonic history of the corresponding source regions. Using a sediment forward mixing model, we obtained the relative sediment contributions and spatial variations of five most important river discharges in the region. The mixing results suggest that the major rivers in the region, i.e., the Yangtze and the Yellow Rivers, are the dominant sediment contributors to the continental margin, and their mixing coefficients could be used to infer relative sediment budgeting. In addition, spatial variations in mixing coefficient in the East China Sea indicate that sediment mixing and partitioning processes in the marine depositional environment have played a part role in propagating the provenance signals as a result of interaction of oceanic currents and tides. The combined method between provenance analysis and mixing modeling provides a feasible way to appreciate sediment budgeting in the geological past.

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Recent collections of sea spiders (Arthropoda: Pycnogonida) from China seas, with some new records and a checklist of the area

Zootaxa ◽

10.11646/zootaxa.4802.2.9 ◽

2020 ◽

Vol 4802 (2) ◽

pp. 361-373

Author(s):

JIANJIA WANG ◽

HESHAN LIN ◽

DINGYONG HUANG ◽

XINQING ZHENG ◽

QINGHE LIU ◽

...

Keyword(s):

East China Sea ◽

New Records ◽

East China ◽

China Seas ◽

The East China Sea ◽

Sea Spiders ◽

China Sea

Though research about sea spiders limited in China seas, a complete checklist has not yet exist so far. After checking recent collections obtained from Shandong, Zhejiang, Fujian and the East China Sea, all these sixty-eight specimens were identified as six species belonged to four families and five genera, including three ones new to China. We described and illustrated them in this study, and also revised all previous records about Chinese pycnogonids and provided a checklist for the presently known forty-one species.

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Morphology and molecular analyses of a newClytiaspecies (Cnidaria: Hydrozoa: Campanulariidae) from the East China Sea

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315414000836 ◽

2014 ◽

Vol 95 (2) ◽

pp. 289-300 ◽

Cited By ~ 5

Author(s):

Jinru He ◽

Lianming Zheng ◽

Wenjing Zhang ◽

Yuanshao Lin ◽

Wenqing Cao

Keyword(s):

New Species ◽

East China Sea ◽

Coastal Waters ◽

Phylogenetic Analyses ◽

Coi Gene ◽

East China ◽

The East China Sea ◽

Separate Species ◽

Molecular Analyses ◽

China Sea

The near-cosmopolitan genusClytiais abundantly found in coastal waters, but difficulties of identification in this genus make nearly all species records of medusae suspect. Complex life histories, ambiguous taxonomic characters, and phenotypic plasticity pose serious problems for accurate species-level identifications and future revisions ofClytiaspecies. In the present study, morphological investigations and molecular analyses ofClytiaspecimens from the coastal waters of the East China Sea revealedClytia gulangensissp. nov. as a new species. DNA barcoding based on the mitochondrial cytochrome oxidase I (COI) gene supported the new species as a separate species withinClytia, and phylogenetic analyses based on mitochondrial 16S rDNA and nuclear 18S rDNA further confirmed this new species to be a distinct lineage. Moreover, detailed observation of medusae and polyps of this species showed sufficient morphological differences from otherClytiaspecies for a diagnosis. Our results indicated that life cycle and DNA-based studies should be a standard approach in future biodiversity investigations ofClytiaspecies.

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Sea surface temperature (SST) anomalies of the Yellow and East China Seas in July of 2020

E3S Web of Conferences ◽

10.1051/e3sconf/202122802006 ◽

2021 ◽

Vol 228 ◽

pp. 02006

Author(s):

Bin Wang ◽

Lei Wu

Keyword(s):

Heat Flux ◽

Surface Temperature ◽

Sea Surface Temperature ◽

East China Sea ◽

Sea Surface ◽

East China ◽

Westerly Wind ◽

China Seas ◽

The East China Sea ◽

China Sea

With the global warming, the long term variations of sea surface temperature and its anomalies in the Yellow and East China Seas, especially for the July of 2020 due to the abnormally torrential rain along Changjiang/Yangtze River Valley, have been investigated based on the Merged Satellite and In-situ Data Global Daily sea surface temperature (MGDSST) provided by the Japan Meteorological Agency (JMA) using the methods of composite and correlation analyses. The results suggest, contrary to warming anomalies in the North-western Pacifica Ocean, the sea surface temperature in the East China Sea is cooler around 0.5°C and that in the East China Sea is cooler around 1.3°C than the normal values. The sea surface temperatures approach the extreme low value in the Yellow Sea and East China Sea in July, and warm up to the normal year in August. In addition, the south-westerly summer monsoon over this region, is proposed to contribute the transport of Kuroshio and its pathway. The obvious westerly wind anomalies, correspond to the lower sea surface temperature over the Yellow and East China Seas in July of 2020, leads to a clear less heat advection from Kuroshio to this region. Further, the low sea surface temperature, leading a downward air motion with a convergence at near sea surface level, is helpful for the enhance of the westerly wind anomalies until the strong surface heat flux in August. This study suggests that the local horizontal circulation advection and net heat flux are also dominated on the heat content of the East China waters. Further quantitative studies are worth conducting.

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Discovery of Wilsonosiphonia fujiae (Rhodomelaceae, Rhodophyta) from the Maldives Islands and transfer of Polysiphonia rhizoidea from Hawaiʻi to Wilsonosiphonia

Phytotaxa ◽

10.11646/phytotaxa.451.1.5 ◽

2020 ◽

Vol 451 (1) ◽

pp. 63-72

Author(s):

GA HUN BOO ◽

TAE OH CHO ◽

ALISON R. SHERWOOD ◽

SUNG MIN BOO ◽

MUTUE TOYOTA FUJII

Keyword(s):

Phylogenetic Analyses ◽

Morphological Characteristics ◽

Red Alga ◽

Species Level ◽

Mitochondrial Cox1 ◽

Upper Intertidal ◽

Algal Genus ◽

Marine Algal ◽

Cryptogenic Species ◽

Rbcl Sequences

Wilsonosiphonia is a newly described marine algal genus with three species. The genus was previously confused with the widely distributed taxon Polysiphonia, and because of this, the taxonomy and distribution of Wilsonosiphonia is likely underestimated. We report the discovery of a minute filamentous red alga, Wilsonosiphonia fujiae (Rhodophyta) in the Maldives Islands, a taxon which was considered endemic to Brazil. Specimens were collected at Fulhadoo, Goidhoo Atoll and Dhidhdhoo Islands, South Ari Atoll, which are ca. 160 km apart, during January and July, 2019, respectively. Thalli formed dense patches on the upper intertidal in regions of shaded rock. Both mitochondrial cox1 and plastid rbcL sequencing confirmed the occurrence of W. fujiae in the Maldives, which is also in agreement with morphological observations. Based on the low pairwise divergences of COI-5P and rbcL sequences between the Maldives and Brazil specimens, we suggest that W. fujiae is a recently introduced yet cryptogenic species in the Maldives. Additionally, as a result of our phylogenetic analyses, it became evident that sequences from the Hawaiian Islands, which were listed as members of the genus Polysiphonia, represent species-level diversity within the genus Wilsonosiphonia. Based on both morphological characteristics and the COI-5P phylogeny, we here reinstate Polysiphonia rhizoidea from Hawaiʻi and transfer it to Wilsonosiphonia, as W. rhizoidea comb. nov.

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Neotypification of Onuphis fukianensis Uschakov & Wu, 1962 and description of a new species of Onuphis (Annelida: Onuphidae) from China seas

Zootaxa ◽

10.11646/zootaxa.4291.2.7 ◽

2017 ◽

Vol 4291 (2) ◽

pp. 347 ◽

Cited By ~ 1

Author(s):

XUWEN WU ◽

KUIDONG XU

Keyword(s):

New Species ◽

East China Sea ◽

Original Description ◽

Type Locality ◽

China Seas ◽

Southern Coast ◽

The East China Sea ◽

The Status ◽

Late Start ◽

A New Species

The original description as well as illustrations of Onuphis fukianensis Uschakov & Wu, 1962 from the East China Sea is simple and no type material is available. The species is peculiar in the genus Onuphis by having very long ceratophores (40 rings on the lateral antennae) and a late start of branched branchiae (chaetiger 47) and thus transferred to the genus Heptaceras. Examination of newly collected material from the region of the type locality allowed us to demonstrate that the reassignment was incorrect. To clarify the status of the species, we designate a neotype and redescribe O. fukianensis. Our examination of historic material revealed another species of Onuphis, which also has relatively long ceratophores and pectinate branchiae that is described below as Onuphis uschakovi sp. nov. The new species highly resembles O. eremita parva Berkeley & Berkeley, 1941, a subspecies described from the southern coast of California. However, the two taxa can be easily distinguished by the number of ceratophoral rings (27–32 vs. 21), the start of subacicular hooks (chaetigers 12–13 vs. chaetiger 8) and the shape of pectinate chaetae (oblique with 8–10 teeth vs. transverse with 15 teeth).

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From famine to feast? Selecting nuclear DNA sequence loci for plant species-level phylogeny reconstruction

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2005.1735 ◽

2005 ◽

Vol 361 (1465) ◽

pp. 211-225 ◽

Cited By ~ 91

Author(s):

Colin E Hughes ◽

Ruth J Eastwood ◽

C Donovan Bailey

Keyword(s):

Dna Sequence ◽

Dna Sequences ◽

Related Species ◽

Nuclear Dna ◽

Sequence Data ◽

Phylogenetic Analyses ◽

Species Level ◽

Gene Trees ◽

Closely Related Species ◽

Nuclear Loci

Phylogenetic analyses of DNA sequences have prompted spectacular progress in assembling the Tree of Life. However, progress in constructing phylogenies among closely related species, at least for plants, has been less encouraging. We show that for plants, the rapid accumulation of DNA characters at higher taxonomic levels has not been matched by conventional sequence loci at the species level, leaving a lack of well-resolved gene trees that is hindering investigations of many fundamental questions in plant evolutionary biology. The most popular approach to address this problem has been to use low-copy nuclear genes as a source of DNA sequence data. However, this has had limited success because levels of variation among nuclear intron sequences across groups of closely related species are extremely variable and generally lower than conventionally used loci, and because no universally useful low-copy nuclear DNA sequence loci have been developed. This suggests that solutions will, for the most part, be lineage-specific, prompting a move away from ‘universal’ gene thinking for species-level phylogenetics. The benefits and limitations of alternative approaches to locate more variable nuclear loci are discussed and the potential of anonymous non-genic nuclear loci is highlighted. Given the virtually unlimited number of loci that can be generated using these new approaches, it is clear that effective screening will be critical for efficient selection of the most informative loci. Strategies for screening are outlined.

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