Study on the photosynthetic performances of Enteromorpha prolifera collected from the surface and bottom of the sea of Qingdao sea area

In this work, the photosynthetic performances of Enteromorpha prolifera thalli collected from the surface and bottom of the sea of Qingdao sea area were studied with chlorophyll fluorescence and oxygraph technology. The samples with the highest photosynthetic activity among their kinds, the floating thalli from the sea surface of the south of the Qingdao Olympic Sailing Center and the sedimentary thalli from the mud surface of the bottom Tuandao bay, were chosen as representatives of surface thalli and bottom thalli, respectively. The results showed that the maximal PSII quantum yield of the floating thalli was significantly lower than the normal level although their photosynthetic activities were relatively high; the photosynthetic potential of the thalli form the mud surface was extremely low. Thus, it is indicated that the floating thalli are seriously stressed by their environment and the thalli from the mud surface are already dead or are dying. On the other hand, the results of the laboratory cultivation showed that the sedimentary thalli cannot regain normal photosynthetic activity even under normal illumination conditions. Thus, the thalli from the mud surface cannot become reproductive source of the alga even if they can reach sea surface again. Therefore, a preliminary conclusion can be reached that, up to mid-July 2008, the environmental conditions of the Qingdao sea area are not suitable for the growth of the alga E. prolifera and for this reason the biomass of E. prolifera, in the area, could be declining.

Complete mitochondrial genome of the sea cucumber Apostichopus japonicus (Echinodermata: Holothuroidea): The first representative from the subclass Aspidochirotacea with the echinoderm ground pattern

Complete mitochondrial genome plays an important role in the accurate revelation of phylogenetic relationships among metazoans. Here we present the complete mitochondrial genome sequence from a sea cucumber Apostichopus japonicus (Echinodermata: Holothuroidea), which is the first representative from the subclass Aspidochirotacea. The mitochondrial genome of A. japonicus is 16,096 bp in length. The heavy strand consists of 31.8% A, 20.2% C, 17.9% G, and 30.1% T bases (AT skew = 0.027: GC skew = 0.062). It contains thirteen protein-coding genes (PCGs), twenty-two transfer RNA genes, and two ribosomal RNA genes. There are a total of 3793 codons in all thirteen mitochondrial PCGs, excluding incomplete termination codons. The most frequently used amino acid is Leu (15.77%), followed by Set (9.73%), Met (8.62%), Phe (7.94%), and Ala (7.28%). Intergenetic regions in the mitochondrial genome of A. japonicus are 839 bp in total, with three relatively large regions of Unassigned Sequences (UAS) greater than 100 bp. The gene order of A. japonicus is identical to that observed in the five studied sea urchins, which confirms that the gene order shared by the two classes (Holothuroidea and Echinoidea) is a ground pattern of echinoderm mitochondrial genomes. Bayesian tree based on the cob gene supports the following relationship: (outgroup, (Crinoids, (Asteroids, Ophiuroids, (Echinoids, Holothuroids)))). (C) 2009 Elsevier B.V. All rights reserved.

Estimates of genetic parameters for growth traits of the sea urchin, Strongylocentrotus intermedius

Heritabilities and genetic and phenotypic correlations were estimated for body weight, test diameter, and test height of the sea urchin from measurements on progeny resulting from 11 sires and 33 dams by artificial fertilization of 3 females by single males, and measurements at 8, 10, and 12 months after metamorphism. Point estimate for heritabilities based on the sire components of variance were moderate to high for body weight (0.21-0.49), test diameter (0.21-0.47), and test height (0.22-0.37). Genetic correlations were significant for body weight with test diameter (0.30similar to0.65) and test height (0.30similar to0.54) and test diameter with test height (0.31similar to0.65). Genetic correlation estimates, derived the nested design and half-sib correlation analysis used in this study, appear to provide reliable estimates. Significant phenotypic correlations were found for body weight with test diameter (0.82similar to0.86) and test height (0.49similar to0.83), and test diameter with test height (0.47similar to0.84). The phenotypic correlations for test height with body weight (0.491) and test diameter (0.467) at 12 months' of age were smaller than those earlier sampling periods.(C) 2004 Published by Elsevier B.V.

Analysis of the sea-level variability along the Chinese coast and estimation of the impact of a CO2-perturbed atmospheric circulation

The relationship between monthly sea-level data measured at stations located along the Chinese coast and concurrent large-scale atmospheric forcing in the period 1960-1990 is examined. It is found that sea-level varies quite coherently along the whole coast, despite the geographical extension of the station set. A canonical correlation analysis between sea-level and sea-level pressure (SLP) indicates that a great part of the sea-level variability can be explained by the action of the wind stress on the ocean surface. The relationship between sea-level and sea-level pressure is analyzed separately for the summer and winter half-years. In winter, one factor affecting sea-level variability at all stations is the SLP contrast between the continent and the Pacific Ocean, hence the intensity of the winter Monsoon circulation. Another factor that affects coherently all stations is the intensity of the zonal circulation at mid-latitudes. In the summer half year, on the other hand, the influence of SLP on sea-level is spatially less coherent: the stations in the Yellow Sea are affected by a more localized circulation anomaly pattern, whereas the rest of the stations is more directly connected to the intensity of the zonal circulation. Based on this analysis, statistical models (different for summer and winter) to hindcast coastal sealevel anomalies from the large-scale SLP field are formulated. These models have been tested by fitting their internal parameters in a test period and reproducing reasonably the sea-level evolution in an independent period. These statistical models are also used to estimate the contribution of the changes of the atmospheric circulation on sea-level along the Chinese coast in an altered climate. For this purpose the ouput of 150 year-long experiment with the coupled ocean-atmosphere model ECHAM1-LSG has been analyzed, in which the atmospheric concentration of greenhouse gases was continuously increased from 1940 until 2090, according to the Scenario A projection of the Intergovermental Panel on Climate Change. In this experiment the meridional (zonal) circulation relevant for sea-level tends to become weaker (stronger) in the winter half year and stronger (weaker) in summer. The estimated contribution of this atmospheric circulation changes to coastal sea-level is of the order of a few centimeters at the end of the integration, being in winter negative in the Yellow Sea and positive in the China Sea with opposite signs in the summer half-year.

Rediscovery of the sea cucumber "Toxodora" pacifica Ohshima, 1915 (Echinodermata : Holothuroidea : Apodida)

The apodous holothurian species originally described by Ohshima ( 1915) as Toxodora pacifica has been rediscovered, and its known geographic range extended from Suruga Bay, Japan to the western side of the Yellow Sea, China. As the genus name Toxodora is no longer available, a new genus name, Neotoxodora Liao, Pawson, and Wei, is proposed. The type material of Neotoxodora pacifica is lost, and a Neotype is named for this species.

cDNA cloning and mRNA expression of the translationally controlled tumor protein (TCTP) gene from Japanese sea perch (Lateolabrax japonicus)

A homologue of the lower vertebrates translationally controlled tumor protein (TCTP) was cloned from the marine fish Japanese sea perch (Lateolabrax japonicus) by the technology of homology cloning. The full-length cDNA sequence of the sea perch TCTP gene contained a 5' untranslated region (UTR) of 47 bp, a 3' UTR of 433 bp, and a putative open reading frame (ORF) of 510 bp encoding a polypeptide of 170 amino acids. The deduced amino acid sequence of the sea perch TCTP gene showed a high similarity to that of zebrafish, rohu, rabbit, chicken and human. Sequence analysis revealed there were a signature sequence of TCTP family, an N-glycosylation site, and five Casein kinase phosphorylation sites in the sea perch TCTP. The temporal expression of TCTP genes in healthy and lipopolysaccharide (LPS) challenged fishes was measured by semi-quantitative reverse transcription-PCR (RT-PCR). The results indicated that LPS could up-regulate the expression of sea perch TCTP in the examined tissues, including head-kidney, spleen and liver.

Formation and evolution of the modern warm current system in the East China Sea and the Yellow Sea since the last deglaciation

To reconstruct the formation and evolution process of the warm current system within the East China Sea (ECS) and the Yellow Sea (YS) since the last deglaciation, the paleoceangraphic records in core DGKS9603, core CSH1 and core YSDP102, which were retrieved from the mainstream of the Kuroshio Current (KC), the edge of the modern Tsushima Warm Current (TWC) and muddy region under cold waters accreted with the Yellow Sea Warm Current (YSWC) respectively, were synthetically analyzed. The results indicate that the formation and evolution of the modern warm current system in the ECS and the YS has been accompanied by the development of the KC and impulse rising of the sea level since the last deglaciation. The influence of the KC on the Okinawa Trough had enhanced since 16 cal kyr BP, and synchronously the modern TWC began to develop with the rising of sea level and finally formed at about 8.5 cal kyr BP. The KC had experienced two weakening process during the Heinrich event 1 and the Younger Drays event from 16 to 8.5 cal kyr BP. The period of 7-6 cal kyr BP was the strongest stage of the KC and the TWC since the last deglaciation. The YSWC has appeared at about 6.4 cal kyr BP. Thus, the warm current system of the ECS and the YS has ultimately formed. The weakness of the KC, indicated by the occurrence of Pulleniatina minimum event (PME) during the period from 5.3 to 2.8 cal kyr BP, caused the main stream of the TWC to shift eastward to the Pacific Ocean around about 3 cal kyr BP. The process resulted in the intruding of continent shelf cold water mass with rich nutrients. Synchronously, the strength of the YSWC was relatively weak and the related cold water body was active at the early-mid stage of its appearance against the PME background, which resulted in the quick formation of muddy deposit system in the southeastern YS. The strength of the warm current system in the ECS and the YS has enhanced evidently, and approached to the modern condition gradually since 3 cal kyr BP.

The history of the Yangtze River entering sea since the last glacial maximum: a review and look forward

This review paper provides a brief review on the development of ideas in the fields of the sea level change of the ECS (East China Sea), the history of the Yangtze River entering the sea and paleochannels in the shelf of the ECS since the Last Glacial Maximum (LGM). The paper summarizes two opposite theories about the Yangtze River entering the sea during the LGM. One theory is that the Yangtze River input a lacustrine in the north of Jiangsu province which was defunct in middle Holocene, and the river was once dry. The other was that the Yangtze River still existed and entered into the Okinawa Trough during the LGM, but scholars share different opinions on which course the river ran across and which place the river input the trough. This paper concludes future work is to study the evolution of the Yangtze River and the paleoclimate and the corresponding events as a whole from the view of regional and even global change, and more attention should be paid to the study on mud sediment, the Yangtze River's response to the changes in climate and sea-level, and the channel metamorphosis.

Structural and Mechanical Properties of the Organic Matrix Layers of Nacre

The type of nanostructure referred to in biomineralization as a mineral bridge has been directly observed and measured in the organic matrix layers of nacre by transmission electron microscopy and scanning electron microscopy. Statistical analysis provides the geometric characteristics and a distribution law of the mineral bridges in the organic matrix layers. Experiments reveal that the nanostructures significantly influences the mechanical properties of the organic matrix layers. In addition, the mechanical analysis illustrates the effects of the nanostructures on the behaviors of the organic matrix layers, and the analytical results explain the corresponding experimental phenomena fairly well. The present study shows that the mineral bridges play a key role in the mechanical performances of the organic matrix layers of nacre. The results obtained provide a guide to the interfacial design of synthetic materials.

An overview of air-sea interface process studies

Recent progress in the study of air-sea interface processes for momentum, heat, moisture and mass transfer are reviewed in the present article. Except for turbulent structure, we have analysed the other physical mechanisms occurring in the wave boundary layer, such as the roles of the sea surface state, droplets and bubbles due to wave breaking, which at least partly account for the existing discrepancies between theory and observations. The experiments, both over the ocean and in the laboratory, are described briefly. In conclusion, a few perspective trends in this area are suggested for further investigation.

Investigations into the perplexing interrelationship of the Genus Takifugu Abe, 1949 (Tetraodontiformes, Tetraodontidae)

The phylogenetic relationships within the genus Takifugu Abe, 1949 (Tetraodontiformes, Tetraodontidae) remain unresolved. Because of the use of Takifugu as model organisms, the resolution of these relationships is crucial for the interpretation of evolutionary trends in biology. Pufferfishes of this genus are comprised of a comparatively small number of species and are mainly distributed along the coastal region of the western part of the Sea of Japan and the coastline of China. Mitochondrial gene sequences were employed to test the phylogenetic hypotheses within the genus. Seventeen species of the genus were examined. Molecular phylogenetic trees were constructed using the maximum parsimony, neighbor-joining, maximum likelihood and Bayesian methods. Our hypothesis of internal relationships within the genus differs from previous hypotheses. Our results indicate that (1) the genus Takifugu is a monophyletic assemblage; (2) the genus is divided into 6 subgroups based on the molecular data; and (3) there is low genetic diversity among the species within this genus. In addition, speciation within Takifugu appears to be driven by hybridization and isolation by distribution. Our results also suggested that the taxonomy in the genus should be clarified based on both molecular and morphological data.

Diving behaviour of freshwater finless porpoises (Neophocaena phocaenoides) in an oxbow of the Yangtze River, China

Dive-depth and swim-speed of a juvenile and an adult free-ranging, Yangtze finless porpoises (Neophocaena phocaenoides) were observed using velocity-time-depth recorders in an oxbow of the Yangtze River. In total, 8222 individual dives were recorded over 59 hours. Two dive types, deep-dive (greater than or equal to 2.7 m) and shallow-dive. were recognized. Horizontal travel distances of two finless pot-poises in a day were 94.4 km and 90.3 km, which were longer than those of oceanic relative species (harbor porpoises, Phocoena phocoena). Although the shallow water limited the maximum dive-depth, dive-duration, and bottom-time of finless porpoises were similar to the harbor porpoises. A sudden drop of swim-speed below 0.25 m s(-1) was frequently observed nearby the maximum dive-depth. This seemed to indicate "turning, around" behaviour, possibly during prey pursuit. (C) 2002 Published by Elsevier science Ltd on behalf of International Council for the Exploration of the Sea.

Population genetic structure of crimson snapper Lutjanus erythropterus in East Asia, revealed by analysis of the mitochondrial control region

The population genetic structure of the crimson snapper Lutjanus erythropterus in East Asia was examined with a 427-bp hypervariable portion of the mtDNA control region. A total of 262 samples were collected and 75 haplotypes were obtained. Neutrality tests (Tajima's and Fu's) suggested that Lutjanus erythropterus in East Asia had experienced a bottleneck followed by population expansion since the late Pleistocene. Despite the low phylogeographic structures in mtDNA haplotypes, a hierarchical examination of populations in 11 localities from four geographical regions using analysis of molecular variance (AMOVA) indicated significant genetic differentiation among regions (Phi(CT) = 0.08564, p < 0.01). Limited gene flow between the eastern region (including a locality in the western Pacific Ocean and two localities in the East Sea) and three geographic regions of the South China Sea largely contributed to the genetic subdivision. However, comparisons among three geographic regions of the South China Sea showed little to no genetic difference. Populations of Lutjanus erythropterus in East Asia are inferred to be divided into two major groups: an eastern group, including populations of the western Pacific Ocean and the East Sea, and a South China Sea group, consisting of populations from northern Malaysia to South China. The results suggest that fishery management should reflect the genetic differentiation and diversity in East Asia. (c) 2006 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.

ISOTOPIC CHARACTERISTICS AND AGE DATING OF THE PUMICE IN OKINAWA TROUGH

The data on the isotope compositions of rubidium, strontium and oxygen in the pumice of Okinawa Trough are reported for the first time. The ages of the pumice were successfully dated with the method of U-series disequilibrium. Then, the material source, crystallization evolution of magma and activity cycles of volcanos are explored. Isotopic data show that pumice magma was originally from the mantle, but had undergone a full crystallization differentiation and had been contaminated to a fair extent by crust-derived materials before the magma was erupted out of the sea floor. According to the dating results available so far, the earliest volcanic eruption in Okinawa Trough occurred about 70,000 a ago and the latest eruption was about 10,000 a B.P. During this period, there were three volcanic eruption cycles which were respectively corresponding to the middle Late Pleistocene, the late Late Pleistocene and the Early Holocene.

Roles of equatorial waves and western boundary reflection in the seasonal circulation of the equatorial Indian Ocean

An ocean general circulation model (OGCM) is used to study the roles of equatorial waves and western boundary reflection in the seasonal circulation of the equatorial Indian Ocean. The western boundary reflection is defined as the total Kelvin waves leaving the western boundary, which include the reflection of the equatorial Rossby waves as well as the effects of alongshore winds, off-equatorial Rossby waves, and nonlinear processes near the western boundary. The evaluation of the reflection is based on a wave decomposition of the OGCM results and experiments with linear models. It is found that the alongshore winds along the east coast of Africa and the Rossby waves in the off-equatorial areas contribute significantly to the annual harmonics of the equatorial Kelvin waves at the western boundary. The semiannual harmonics of the Kelvin waves, on the other hand, originate primarily from a linear reflection of the equatorial Rossby waves. The dynamics of a dominant annual oscillation of sea level coexisting with the dominant semiannual oscillations of surface zonal currents in the central equatorial Indian Ocean are investigated. These sea level and zonal current patterns are found to be closely related to the linear reflections of the semiannual harmonics at the meridional boundaries. Because of the reflections, the second baroclinic mode resonates with the semiannual wind forcing; that is, the semiannual zonal currents carried by the reflected waves enhance the wind-forced currents at the central basin. Because of the different behavior of the zonal current and sea level during the reflections, the semiannual sea levels of the directly forced and reflected waves cancel each other significantly at the central basin. In the meantime, the annual harmonic of the sea level remains large, producing a dominant annual oscillation of sea level in the central equatorial Indian Ocean. The linear reflection causes the semiannual harmonics of the incoming and reflected sea levels to enhance each other at the meridional boundaries. In addition, the weak annual harmonics of sea level in the western basin, resulting from a combined effect of the western boundary reflection and the equatorial zonal wind forcing, facilitate the dominance by the semiannual harmonics near the western boundary despite the strong local wind forcing at the annual period. The Rossby waves are found to have a much larger contribution to the observed equatorial semiannual oscillations of surface zonal currents than the Kelvin waves. The westward progressive reversal of seasonal surface zonal currents along the equator in the observations is primarily due to the Rossby wave propagation.