Rapid amplification of cDNA ends (RACE) and real-time polymerase chain reaction (RT-PCR) were carried out to analyze the CYP4 gene expression in polychaete Marphysa sanguinea exposed to benzo[a]pyrene (BaP) in this study. The full length of MsCYP4 cDNA was 2 470 bp, and it encoded 512 amino acids. The deduced amino acid sequence showed 47% identity with CYP4F from frog Xenopus tropicalis and shared high homology with other known CYP4 sequences. To analyse the role of CYP4 in protecting M. sanguinea from BaP exposure, three BaP groups were established: 0.5, 5 and 50 μg/L. Polychaetes were sampled after 3, 7 and 12 d. At 0.5 μg/L, the effect of BaP on MsCYP4 gene expression increased with time prolonged. MsCYP4 gene expression curve showed U-shaped trend with time in 5 and 50 μg/L BaP groups. Therefore, MsCYP4 gene may play an important role in maintaining the balance of cellular metabolism and protecting M. sanguinea from BaP toxicity.

The cyp19a1a gene encodes an aromatase that plays a key role in sex differentiation of the gonad. The first bacterial artificial chromosome (BAC) sequence of half-smooth tongue sole (Cynoglossus semilaevis) containing the intact cyp19a1a gene was reported and the conservation and synteny of the cyp19a1a gene among teleosts were analyzed in the study. The BAC is 107 367 bp in size, with an overall guanine-cytosine (GC) content of 43.44%, and contains 4.38% transposable elements. Nine genes were predicted, including seven functional genes and two hypothetical genes. The cyp19a1a gene of all tested teleosts has nine exons and eight introns, and potential binding sites flanking the transcriptional start site are conserved. The expression pattern among teleosts is also similar during ovarian differentiation. Synteny analysis revealed a conserved gene cluster PKH4B-SL9A5-FHOD3-CEBPG-CEBPA among teleosts. These findings suggest that, among teleosts, cyp19a1a genes not only have similar genomic structures, but also have conserved functions. The genomic environment of cyp19a1a in tongue sole is not universal in teleosts, reflecting the particular evolution of tongue sole cyp19a1a after it diverged from the other teleosts.

In variational methods, coupled parameter optimization (CPO) often needs a long minimization time window (MTW) to fully incorporate observational information, but the optimal MTW somehow depends on the model nonlinearity. The analytical four-dimensional ensemble-variational (A-4DEnVar) considers model nonlinearity well and avoids adjoint model. It can theoretically be applied to CPO. To verify the feasibility and the ability of the A-4DEnVar in CPO, “twin” experiments based on A-4DEnVar CPO are conducted for the first time with the comparison of four-dimensional variational (4D-Var). Two algorithms use the same background error covariance matrix and optimization algorithm to control variates. The experiments are based on a simple coupled ocean-atmosphere model, in which the atmospheric part is the highly nonlinear Lorenz-63 model, and the oceanic part is a slab ocean model. The results show that both A-4DEnVar and 4D-Var can effectively reduce the error of state variables through CPO. Besides, two methods produce almost the same results in most cases when the MTW is less than 560 time steps. The results are similar when the MTW is larger than 560 time steps and less than 880 time steps. The largest MTW of 4D-Var and A-4DEnVar are 1 200 time steps. Moreover, A-4DEnVar is not sensitive to ensemble size when the MTW is less than 720 time steps. A-4DEnVar obtains satisfactory results in the case of highly nonlinear model and long MTW, suggesting that it has the potential to be widely applied to realistic CPO.

Fifty-seven stations (48 grid stations and nine stratified stations) were sampled across the study region (67.000°-88.394°N, 152.500°-178.643°W) during the 4th Chinese National Arctic Research Expedition (CHINARE 4) from July to August 2010 by the icebreaker R/V Xuelong. A total of 24 species of Hydromedusae were identified from 130 zooplankton samples, of which seven species belonged to Automedusa, eight species to Anthomedusae, four species to Leptomedudae, and three species to Siphonophora. Catablema multicirratum Kishinouye, 1910, Bougainvillia bitentaculata Uchida, 1925, and Euphysa japonica (Maas, 1909) were recorded for the first time in the Arctic sea. In the present paper, 18 species of Hydromedusae were described and illustrated, of which three species were described for the first time in the Arctic sea, and 15 species were described for the first time in China.

Genetic diversity of cultivated populations was investigated using assay of vertical slab polyacrylamide gel electrophoresis in 4 species of shrimps,which were Penaeus japonicus,Penaeus monodon,Penaeus vannamei and Metapenaeus ensis.The results showed that the mean number of alle-les per locus(A) is 1.3±0.2,1.3±0.1,1.3±0.1 and 1.3 ±0.1 respectively; the percentage of polymorphic loci(P_0.95) is 12.5,6.7,20 and 23.5 respectively; the expected heterozygosity(H_e) is 0.042±0.034,0.042±0.031,0.094±0.042 and 0.097±0.047 respectively; and the observed heterozygosity(H₀)is 0.029±0.024,0.028±0.023,0.154±0.082 and 0.150±0.084 respectively.The difference of genetic diversity is obvious in 4 species of shrimps.The degree of genetic diversity is M.ensis > P.vannamei > P.japonicus > P.monodon.In short,the lower level of genetic diversity is estimated in 4 species of shrimps.

Some geochemical investigations of interstitial water in surface sediments were conducted at the Changjiang Estuary and the outer shelf of the East China Sea. It is found that the changes of alkalinity (≈ the concentration of HCO₃^-), and NH₄⁺ diffusion fluxes have a correlation with the actions of benthic fauna. The fluxes measured by gradient method may have a direct linear correlation with the sedimentation rate of this area.

The Shenzhou-4 spaceborne (SZ-4) altimeter waveforms were processed, and then the significant wave heights (SWH) was retrieved on the basis of waveform fitting and waveform retracking. Waveforms processing includes the waveform 1 s averaging, the elimination of thermal noise and the waveforms normalization. Double peaks were found on each SZ-4 waveform, and it was pointed out that the region of waveforms with the second peak is abnormal and its effects on the whole waveform in the waveform fit should be taken into consideration. To obtain the width of the waveform leading-edge, a method was proposed to find the starting point of waveform, and the half-power point of waveform was found by retracking the waveform. The normalized waveforms were fitted with the Haynes model by using the weighting least square fit method. Then the selections of the weighting coefficients and their effects on significant wave hight retrieving were discussed, and the optimal five-region weighting method was proposed. At last, the SWH data of SZ-4 altimeter retrieved by using the proposed method were compared with those of ERS-2 and Jason-1 altimeter, and it was concluded that the SZ-4 altimeter can detect significant wave height.

The influence of macronitrogen (NO₃^- and NH₄⁺) addition with Ulva pertusa on dissolved inorganic carbon system in seawater was studied. The results indicate that p (CO₂) and HCO₃^- concentration decrease significantly, while pH and CO₃^2- concentration increase significantly. When the concentration of NO₃^- was less than 71 μmol/dm³ or NH₄⁺ was less than 49.7 μmol/dm³, dissolved inorganic carbon (DIC) absorption rates by Ulva pertusa generally increased with the increasing of nitrogen concentration. The DIC decreased 151 μmol/dm³ with the addition of 71 μmol/dm³ NO₃^- and decreased 232 μmol/dm³ with the addition of 49.7 μmol/dm³ NH₄⁺ after the experiment compared with DIC measured without nitrogen addition. A significant negative-correlation was found between △c (DIC) and growth rate (μ) of Ulva pertusa (r=-0.91, P <0.000 1, n=11). NH₄⁺ had more influence on the species of inorganic carbon system than NO₃^-.

The effect of the bacterial strain CI4 on the germination of spores from the green alga Ulva pertusa was assayed and it was found that the bacterial biofilm and cell-free supernatant strongly inhibited spore germination. In attempts to define the chemical nature of the antifouling substance in the supernatant of CI4, the culture supernatants were tested for activity after heat treatment, enzymatic treatments, size fractionation, and separation into aqueous and organic fractions. Results suggest that this bacterium produces an extracellular component with specific activity toward algal spores that was heat-sensitive and between 3 and 10 kDa in molecular size. The exposure of the organic phase fraction to spores showed inhibitive effect on spore germination. Pronase and carboxypeptidase y did not significantly affect the activity of inhibitory component, suggesting that the component was not a protein or a peptide. The bacterium CI4 was identified as Pseudoalteromonas haloplanktis based on the phenotypic characters and 16S rRNA gene analysis.

This paper expounds primarily on the physiological mechanism of the mature process and release of Ruditapes philippinarum's eggs. A natural dry condition, immersion in NH₄OH seawater, and crude extracted shedding hormone, were the necessary physiological conditions and factors which make eggs reach physiological maturity, and make the female or male clam spaw and spermiate. At the same time, it has been shown that the physiological action of the NH₄OH seawater may stimulate the respiration of the eggs, and that the comsumption oxygen raises 15.17μl. The shape of eggs turns from oval into round; and the ultrastructure of the nucleus and cytoplasm show strengthened metabolic activity. Besides, it has been substantiated that the shedding hormone exist in the gonad of female clams. The shedding hormone may be a heat labile protein. The result may be of theoretial importance and economic value to artifical reproduction of the molluscs.