Effect of light period on egg-discharge of gametophyte clones of Undaria pinnatifida (Phaeophyta)

A sporeling culture method using gametophyte clones developed in the early 1990s led to egg discharge occurring in the dark 5 min after the start of the dark period under growth under a 11:13 L-D photoperiod. The course of egg discharge could be disturbed by light, with irradiance as low as 5-6 mu mol photon m(-2) s(-1) causing 75-80% of the discharged eggs to detach from the oogonia and consequently to die within several hours. In order to enhance outgrowth rate of young sporophytes, a study was conducted to test the effect of controlling darkness in the period 2-3 h after dusk. When the slides were transferred from the standard 11:13 L-D regime to continuous light, eggs were discharged 5 min after the end of the light phase and peaked 5-l5 min later on first day after transfer, indicating that the female gametes "remember" the light-dark regime. This suggests the existence of an endogenous circadian rhythm. During the second and third days, very few eggs were discharged throughout the 11 h of the normal light phase of the L-D regime, indicating the inhibitory effect of continuous light and that the rhtyhm is easily damped by light.

Mass culture of Undaria gametophyte clones and their use in sporeling culture

Undaria pinnatifida (Harv.) Sur. is one of the three main seaweed species under commercial cultivation in China. In the mid-1990s the annual production was about 20000 tons dry. The supply of healthy sporelings is key to the success of commercial cultivation of Undaria. Previous studies demonstrated that instead of the zoospore collection method, sporelings can be cultured through the use of gametophyte clones. This paper reports the experimental results on mass culture of clones and sporeling raising in commercial scale. Light had an obvious effect on growth of gametophyte clones. Under an irradiance of 80 mumol m(-2) s(-1) and favorable temperature of 22-25degreesC, mean daily growth rate may reach as high as 37%. Several celled gametophyte fragments were sprayed onto the palm rope frame. Gametogenesis occurred after 4-6 days. Juvenile sporeling growth experiments showed that nitrate and phosphate concentrations of 2.9 10(-4) mol 1(-1) and 1.7 10(-5) mol 1(-1) were sufficient to enable the sporelings to maintain a high daily growth rate. Sporelings can reach a length of 1 cm in a month. Since 1997, extension of the clone technique has been carried out in Shandong Province. Large-scale production of sporelings for commercial cultivation of 14 and 31 hectares in 1997 and 1998 had been conducted successfully.

Langmuir-Blodgett film of phycobilisomes from blue-green alga Spirulina platensis

The phycobilisomes were isolated from blue-green alga Spirulina platensis, and could form monolayer film at air/water interface. The monolayer film of phycobilisomes was transferred to newly cleaved mica, and coated with gold. Scanning tunneling microscope was used to investigate the structure of the Langmuir-Blodgett film of phycobilisomes. It was shown that phycobilisomes in the monolayer arrayed in rows with core attaching on the substrate surface and rods radiating towards the air phase, this phenomenon was similar to the arrangement of phycobilisomes on cytoplasmic surface of thylakoid membrane in vivo. The possible applications of the Langmuir-Blodgett film of phycobilisomes were also discussed.

Transient expression of lacZ in bombarded unicellular green alga Haematococcus pluvialis

This paper reports for the first time the transient expression of a reporter gene, LacZ, in the unicellular green alga Haematococcus pluvialis. By employing the micro-particle bombardment method, motile cells in the exponential phase showed transient expression of lacZ. This was detected in bombarded motile cells under the rupture-disc pressures of 3103 KPa and 4137 KPa. Transient expression of LacZ gene could not be observed in non-motile cells of this alga under the same transformation condition. No LacZ background was found in either the motile cells or the non-motile cells. The study suggests a promising potential of the SV40 promoter and the lacZ reporter gene in genetic engineering of unicellular green algae.

A new method of Laminaria japonica strain selection and sporeling raising by the use of gametophyte clones

One-celled female and male gametophytes of three Laminaria japonica strains were isolated, cultured and gametophyte clones were formed. A technique combining strain selection with sporeling raising by the use of these female and male gametophyte clones was studied. Experiments on 9 different crossing combinations was conducted in November of 1997 in Qingdao, P. R. China. The main economic characteristics, frond length and fresh weight, of sporophytes of different crossing combinations were measured. F-1 sporophytes of No. 2 showed a higher fresh weight and longer length, therefore, No. 2 (Wh860 + x Lid) was selected as a good combination. Its parental female and male gametophyte clones are being mass cultured for sporeling production. By this method, the time needed for strain selection was shortened from 5-6 to 2 years. As compared with the routine method of sporeling raising by the collection of zoospores, the time of sporeling raising of this method decrease by 50%, and the production cost is also reduced by 50%. It is believed that this method will be labour and time saving and a more economic way for strain selection and sporeling raising in L. japonica cultivation industry.

Translocation of assimilates in Undaria and its cultivation in China

Undaria cultivation on a commercial scale began in China only in the last decade. Today, Undaria pinnatifida is the main species under cultivation concentrated in two provinces, Liaoning and Shandong. The annual production in the early nineties was 8000-13 000 tons dry weight, which is two or three times the pre-1980 figures. The raft cultivation method maintaining the alga at the desired depths generally ensures the light saturated rate of photosynthesis on clear days, and enhances production. Under the cultivated condition, the calculated annual primary productivity of this alga is 160 g C m(-2) y(-1). Translocation of C-14-labelled photoassimilates in rapidly growing sporophyte of Undaria pinnatifida was studied in the open sea. Samples from different parts of the blade with counterparts exposed to tracer ((NaHCO3)-C-14) showed that the translocation that occurred mainly from the tip of the blade to the growing region had obvious source-sink relationship. It took 20 minutes to translocate the labelled photoassimilates from the epidermis, via cortex, to the medulla of the midrib, where rates of translocation averaging 42-48 cm h(-1) were observed in the open sea. Production experiments of tip-cutting of the blades showed an increased production of 9%.

Integrated cultivation of the red alga Kappaphycus alvarezii and the pearl oyster Pinctada martensi

The effect of simultaneously cultivating the pearl oyster Pinctada martensi and the red alga Kappaphycus alvarezii on growth rates of both species was investigated in laboratory and field studies conducted from December 1993 to June 1995. The two study sites were in subtidal areas 100 km apart off the east coast of Hainan Island, China. Pearl oysters were cultivated in the center of an algal farm and red alga was cultivated in the center of the pearl oyster farm. These field experiments showed higher growth rates of both P. martensi and K. alvarezii in a co-culture system than in a monospecies culture system. Laboratory studies showed that the algae removed nitrogenous wastes released by pearl oysters. Algae treated with pearl oyster wastes grew much faster than those without oyster wastes. Algae treated with the seawater to which NH4Cl, NaNO3 and NaNO2 were added grew at the same rate as those treated with natural seawater containing oyster nitrogenous wastes, suggesting that enhanced growth of algae in the co-culture system was largely due to nitrogenous metabolites of the pearl oysters. In the co-culture, growth of pearl oysters was positively influenced by the presence of rapidly growing algae but when seawater temperature decreased below 20 degrees C, the algae grew slowly and there was no measurable benefit of mixed culture to either algae or pearl oyster.

SATELLITE REMOTE-SENSING PREDICTION OF JAPANESE PILCHARD FISHING GROUND IN THE HUANGHAI SEA AND THE EAST-CHINA-SEA

The thermophily, fishing season and central fishing ground of Japanese pilchard (Sardinops melanosticta) were studied by using satellite remote sensing (SRS) and other methods in Haizhou Bay and Tsushima waters during 1986-1990. A rapid prediction method of fishing ground is presented. Moreover, the results indicated that the thermophilic values of the fish stock are 11-20 degrees C and both fishing grounds are in increasing temperature process from the beginning to the end of the fishing period. The Japanese pilchards gather vigorously at the sea surface temperature of 15-17 degrees C. The water temperature is a key factor affecting the fishing season and the catch of the fishing ground. The increasing temperature process restricts the fishing season development and central fishing ground formation. The accuracy of 15 predictions made in the Haizhou Bay fishing ground is up to 91.3%, and 37 predictions made in the Tsushima, fishing ground shorten the fish detection time by 13.4% - 22% on the average.

SOME ASPECTS OF THE GROWTH OF GRACILARIA-TENUISITIPITATA IN POND CULTURE

The effect of temperature, salinity, nitrogen, culture density and depth on the growth of Gracilaria tenuistipitata were investigated between April 1985 and March 1986 in outdoor ponds in Guangxi Province, South China. The mean annual growth rate was 2.4% per day. Under favourable temperatures of 20-30-degrees-C, daily growth rate may reach as high as 3.3%. Salinity had an obvious effect on growth and photosynthesis and growth peaked at 21 parts per thousand, with a broad plateau between 7-27 parts per thousand. Growth experiments showed that a total nitrogen (NH4-N plus NO3-N) concentration of 4 muM was sufficient to enable the plants to maintain a daily growth rate of 2.7%. The best growth of the plant was obtained at a culture density of 0.5-1 kg M-2 and a culture depth of 30 cm in the pond.

Mineralogy of smectites in the surface sediments from the East Pacific and its significance

XRD, TEM, SEM and EDS are employed to analyze smectites in the clay fraction of the surface sediments from the East Pacific. It is shown from the XRD results that the clay fraction consists of about 20% smectites. Three types of smectites are identified, Fe-rich (Type I), Fe, Mg-rich (Type II) and Na,Ca smectite (Type III), and most of them are not well-crystallized. Type I is widely distributed in sediments, showing honeycomblike in the SEM, and aggregated or dispersive hairlike, or cloudy assemblage with a bit curl near its edge in the TEM. This type is considered to be typomorphic type of authigenic smectite in the East Pacific. Type II is similar to Type I in micromorphology in the TEM, showing a transition micronite, while Type III is tabletlike in the TEM with an unclear edge. Type I may be altered from volcanics and some of them even precipitated from the low subthermal water. Type II could also be formed in the ocean floor, while Type III comes from dry and distant continental area. This study suggests that the characteristic of chemical composition and morphology of smectite may give a clue to understand sediment source, origin of minerals and sedimentation in the deep sea.

A quasi-synoptic interpretation of water mass distribution and circulation in the western North Pacific II: Circulation

Using the data of conductivity-temperature-depth (CTD) intensive observations conducted during Oct.-Nov. 2005, this study provides the first three-dimension quasi-synoptic description of the circulation in the western North Pacific. Several novel phenomena are revealed, especially in the deep ocean where earlier observations were very sparse. During the observations, the North Equatorial Current (NEC) splits at about 12A degrees N near the sea surface. This bifurcation shifts northward with depth, reaching about 20A degrees N at 1 000 m, and then remains nearly unchanged to as deep as 2 000 m. The Luzon Undercurrent (LUC), emerging below the Kuroshio from about 21A degrees N, intensifies southward, with its upper boundary surfacing around 12A degrees N. From there, part of the LUC separates from the coast, while the rest continues southward to join the Mindanao Current (MC). The MC extends to 2 000 m near the coast, and appears to be closely related to the subsurface cyclonic eddies which overlap low-salinity water from the North Pacific. The Mindanao Undercurrent (MUC), carrying waters from the South Pacific, shifts eastward upon approaching the Mindanao coast and eventually becomes part of the eastward undercurrent between 10A degrees N and 12A degrees N at 130A degrees E. In the upper 2 000 dbar, the total westward transport across 130A degrees E between 7.5A degrees N and 18A degrees N reaches 65.4 Sv (1 Sv = 10(-6) m(3)s(-1)), the northward transport across 18A degrees N from Luzon coast to 130A degrees E is up to 35.0 Sv, and the southward transport across 7.5A degrees N from Mindanao coast to 130A degrees E is 27.9 Sv.

A SINGULAR EXACT SOLUTION FOR NONLINEAR SHALLOW-WATER ON A ROTATING EARTH

In this paper, we present an exact solution for nonlinear shallow water on a rotating planet. It is a kind of solitary waves with always negative wave height and a celerity smaller than linear shallow water propagation speed square-root gh. In fact, it propagates with a speed equal to (1 + a/h) square-root gh(1 + a/h) where a is the negative wave height. The lowest point of the water surface is a singular point where the first order derivative has a discontinuity of the first kind. The horizontal scale of the wave has actually no connection with the water depth.

Vertical structure and evolution of the Luzon Warm Eddy

Eddies are frequently observed in the northeastern South China Sea (SCS). However, there have been few studies on vertical structure and temporal-spatial evolution of these eddies. We analyzed the seasonal Luzon Warm Eddy (LWE) based on Argo float data and the merged data products of satellite altimeters of Topex/Poseidon, Jason-1 and European Research Satellites. The analysis shows that the LWE extends vertically to more than 500 m water depth, with a higher temperature anomaly of 5A degrees C and lower salinity anomaly of 0.5 near the thermocline. The current speeds of the LWE are stronger in its uppermost 200 m, with a maximum speed of 0.6 m/s. Sometimes the LWE incorporates mixed waters from the Kuroshio Current and the SCS, and thus has higher thermohaline characteristics than local marine waters. Time series of eddy kinematic parameters show that the radii and shape of the LWE vary during propagation, and its eddy kinetic energy follows a normal distribution. In addition, we used the empirical orthogonal function (EOF) here to analyze seasonal characteristics of the LWE. The results suggest that the LWE generally forms in July, intensifies in August and September, separates from the coast of Luzon in October and propagates westward, and weakens in December and disappears in February. The LWE's westward migration is approximately along 19A degrees N latitude from northwest of Luzon to southeast of Hainan, with a mean speed of 6.6 cm/s.

桑沟湾贝藻养殖区附着生物生态效应研究

附着生物又称污损生物，是附生在海洋设施和生物体表面的动物、植物和微生物等生物的总称（Azis et al., 2001）。附生在养殖器材和生物体表面的数量巨大的附着生物，对贝类养殖和海湾生态系统内的物质和营养盐循环等多个方面产生影响。本研究以北方重要的养殖海湾----桑沟湾为研究对象，对贝藻养殖区附着生物的群落演替及其生态效应进行了研究。主要研究结果如下： ① 2007年5月至2008年5月，采用挂网的方法对桑沟湾栉孔扇贝和海带混养区的附着生物的季节变化进行了研究。结果显示挂网上的附着生物具有显著的季节变化特征，网片上的附着生物湿重与水温的变化相一致，生物量为3~1210 g•m-2。2月份附着生物的生物量最低，8月份最高。2007年9月至11月，对栉孔扇贝养殖笼上和贝壳上的附着生物种类和数量进行了研究。结果显示9月份养殖笼上附着生物的湿重约为1.94 kg，10月份降至0.99 kg，11月份又稍有增加，为1.03 kg。扇贝壳上的附着生物变化趋势与养殖笼上的相同，9~11月份壳上附着生物的数量约0.49~2.09 g。扇贝养殖笼上可鉴定的大型附着生物约23种，包括藻类、海鞘类、苔藓虫类、环节动物、腔肠动物、软体动物、甲壳动物和海绵动物等。玻璃海鞘、柄海鞘、紫贻贝和苔藓虫等是附着生物群落中的优势种。 ② 通过在栉孔扇贝和虾夷扇贝上壳上添加不同重量的“模拟附着生物”（速凝水泥）的方法，研究了贝壳上附着生物的重量对这两种扇贝生长和存活的影响。结果显示水泥重量是上壳重0.5-3倍的各组实验组扇贝的生长和存活与对照组（未添加水泥的扇贝）之间没有显著差异。说明贝壳上附着生物重量为上壳的3倍重时，也不会显著影响扇贝生长存活。9-11月份贝壳上的自然附着生物的重量约为1.47-2.09 g，为上壳重的28.16 (±38.6)%—31.29 ± (31.63)%。因此，贝壳上附着的生物重量不太可能对扇贝的生长存活造成显著的负面影响。 ③ 在桑沟湾现场测定了玻璃海鞘和柄海鞘的生物沉积速率。9月份（水温约24℃）玻璃海鞘和柄海鞘的生物沉积速率分别为32.14和90.06 mg•ind-1•d-1或（858.99 和467.76 mg•gdw-1•d-1），据此计算，养殖笼上的两种海鞘的生物沉积速率约为84.29 mg•m-2•d-1。海区的自然沉积速率为41.49 mg•m-2•d-1；玻璃海鞘和柄海鞘沉积物中有机质含量分别为14.34%和13.77%，对照组海区自然的有机质含量为14.36%；以上三者有机碳的含量分别为24.72%，23.74%和24.76%；氮的含量分别为0.27%和0.25%，自然沉积物中的氮含量为0.30%。9月份扇贝养殖笼上附着的海鞘将产生2588.16吨的沉积物，即向底部沉积363.77吨的有机物、6.99吨的氮和1.79吨的磷。 ④ 通过测定扇贝养殖笼上优势种附着生物--玻璃海鞘、柄海鞘和贻贝的摄食、呼吸和排泄，研究了这些优势种类对贝类养殖和海湾环境的影响。9月份（水温约24.5℃）玻璃海鞘和柄海鞘对颗粒有机物（POM）的摄食率分别为14.30 和17.01 mg• h-1•ind-1。根据实验结果计算这两种海鞘摄取的颗粒有机物相当于312个扇贝的摄取量，大于笼内养殖的扇贝的摄取量；玻璃海鞘和柄海鞘的耗氧率分别约为0.32和0.18 mg•h-1•ind-1，养殖笼上的这两种海鞘消耗的溶解氧约等于75个扇贝消耗的溶解氧。栉孔扇贝、玻璃海鞘、柄海鞘和贻贝的排氨率分别为33.66 ±11.34，117.90±23.46，35.91±6.22，28.08±3.41 ug NH4-N•gdw-1•h-1。以此估算，9月份玻璃海鞘、柄海鞘和贻贝每天排泄的氨氮约为654.08 kg，相当于16467吨栉孔扇贝（鲜重）排泄的氨氮。海鞘和贻贝排泄的氨氮可提供浮游植物等所需的2.75%的氮，可以提供1204吨海带的生长所需的氮。 ⑤ 一个养殖笼内的栉孔扇贝和全部附着生物（Scallop Culture Unit, SCU）在夏季（6-9月）对颗粒有机物的摄食速率约为43.13-98.94 mg/h，平均74.05 mg/h，期间桑沟湾养殖的栉孔扇贝及附着生物摄取的POM约为1279.58吨；同期，SCU对氨氮和磷（PO4-P）的排泄速率分别为125.59-1432.23 μmol•h-1和76.2-252.89μmol•h-1，期间桑沟湾养殖扇贝及附着生物排泄的氮磷分别为211.09 吨和83.79 吨。一串牡蛎及吊绳和牡蛎壳上的附着生物（Oyster Culture Unit, OCU），夏季摄食率为5-41.43μmol•h-1，耗氧率为16.54-41.76μmol•h-1，对氨氮和磷（PO4-P）的排泄速率分别为35.56-489.34μmol•h-1 和9.92-16.68μmol•h-1。以此估算，夏季OCU可摄取POM535.68吨，消耗溶解氧955.58吨，排泄氮磷分别为62.37 吨和15.50 吨。

Synthesis, crystal structure and biological activities of N '-(4-methoxybenzylidene)-2-(1H-1,2,4-triazol-1-yl) acetohydrazide

The title compound, N'-(4-methoxybenzylidene)-2-(1H-1,2,4-triazol-1-yl)acetohydrazide, was synthesized and its structure was confirmed by means of IR, MS,H-1 NMR and elemental analysis. The single crystal structure of the title compound was determined by X-ray diffraction. The preliminary biological test shows that the synthesized compound has a low antifungal activity.