Effects of ration, temperature and body weight on metabolism in young black porgy

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｍｅｔａｂｏｌｉｓｍｉｎｆｉｓｈｉｎｃｌｕｄｅｓｓｔａｎｄａｒｄｍｅｔａｂｏｌｉｓｍ(ＲＳ)ｒｏｕｔｉｎｅｍｅｔａｂｏｌｉｓｍ(ＲＲ),ｓｐｅｃｉｆｉｃｄｙｎａｍｉｃａｃｔｉｏｎ(ＳＤＡ)ａｎｄａｃｔｉｖｅｍｅｔａｂｏｌｉｓｍ(ＲＡ),ｒｅｌａｔｅｄａｓ:　　ＲＴ=ＲＳ ＲＲ ＳＤＡ ＲＡｗｈｅｒｅＲＳｉｓｔｈｅｍｅｔａｂｏｌｉｓｍｏｆｔｈｅｆｉｓｈａｔｒｅｓｔ;ＲＲｔｈｅｍｅｔａｂｏｌｉｓｍｏｆｔｈｅｒｏｕｔｉｎｅｌｙａｃｔｉｖｅｆｉｓｈ;ＳＤＡｔｈｅｍｅｔａｂｏｌｉｓｍｏｆｔｈ…     

Life cycle and production of chironomidae (diptera) in Biandantang, a typical macrophytic lake (Hubei, China)

ＩＮＴＲＯＤＵＣＴＩＯＮＡｌｔｈｏｕｇｈｄｅｓｃｒｉｐｔｉｏｎｏｆｌｉｆｅｈｉｓｔｏｒｙａｎｄｅｓｔｉｍａｔｅｓｏｆａｎｉｍａｌｐｒｏｄｕｃｔｉｏｎｈａｖｅａｌｏｎｇｈｉｓｔｏｒｙ (Ｌｉｎ ｄｅｇａａｒｄ ,1 989) ,ｆｅｗｓｔｕｄｉｅｓｏｎｔｈｅｐｒｏｄｕｃｔｉｏｎｒａｔｅｏｆｂｅｎｔｈｉｃｍａｃｒｏｉｎｖｅｒｔｅｂｒａｔｅｓｗｅｒｅｃａｒｒｉｅｄｏｕｔｉｎＣｈｉｎｅｓｅｗａｔｅｒｓ (Ｌｉａｎｇ ,1 984 ) .Ｗｉｔｈｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｆｉｓｈｅｒｉｅｓａｎｄｔｈｅｄｅｔｅｒｉｏｒａｔｉｏ…     

Optimum temperature for the growth performance of juvenile orange-spotted grouper （Epinephelus coioides H.）

Effects of water temperature （17, 21, 25, 30 and 35℃） and body size （14.75-281.41 g initial body weight） on food consumption, growth, feed conversion, and dry matter content in orange-spotted grouper fed to satiation were investigated. The combined effect of temperature （T, ℃） and body weight （W, g） on maximum food consumption （Cmax, g/day） was described as： InCmax=-7.411＋0.828 InW＋0.317T4）.004 7T2, and the optimum feeding temperature was 33.9℃. The combined effect of temperature and body weight on growth （G） was described as： lnG=-4.461-0.2081nW＋0.394T-0.006 3T^2. The optimum growth temperature was 31.4℃, whereas overall growth rates were high at 25, 30 and 35 ℃. Feed conversion efficiencies （FCE, %）, increasing first and then decreasing with increasing temperature, averaged from 1.8 to 2.1 in terms of dry weight of food fish. The optimum temperature for FCE tended to be lower than that for growth or feeding. Dry matter content increased with both increasing water temperature （17, 25, 30 and 35℃） and body weight, and the combined effect of temperature and body weight on dry matter content （DM, %） was described as： lnDM =3.232＋0.01 4 lnW-0.004 4T＋0.001 2TInW.     

Effect of temperature under unfavourable conditions on oxygen uptake of larval herring,Clupea harengus

Oxygen uptake under starvation and short periods of sudden temperature change was measured for larval herring (Clupea harengus L.) reared at average temperature of 7.3, 11 and 12.9°C. Larval stages between first feeding and premetamorphosis were used. For comparison, the routine oxygen uptake (ROU) was also investigated and followed the relationshipQ=0.974+0.174tW ^−0.210, whereQ is in μg/(mg·h),W is dry body weight in mg andt is temperature in °C. The oxygen uptake under starvation (SOU, deprived of food for 24 h) was different from the routine when the larval dry weight was less than 0.6–0.8 mg; it increased with temperature and body weight giving the relationshipQ=1.568+0.110tW ^0.380; if the larval dry weight was more than 0.6–0.8 mg, it reverted to the norm (Q=1.704+0.078tW ^−0.349). The oxygen uptake was tested in short periods (3 h) of sudden temperature changes in six groups: 7.3 to 11, 7.3 to 12.9, 11 to 7.3, 11 to 12.9, 12.9 to 7.3 and 1.29 to 11°C. The oxygen uptake in the 7.3 to 12.9 and 12.9 to 7.3°C groups varied in a way similar to that of the larvae under starvation. The other four groups' oxygen uptake were more or less normal.     

Energy flow in Branchiura sowerbyi (Oligochaeta: tubificidae) in a shallow macrophyte-dominated lake, Biandantang Lake

The energy flow ofBranchiura sowerbyi was studied for the first time in China in a shallow macrophytic lake, Biandantang Lake, Hubei Province. The energy flow was calculated from the measurement of flesh production (12.5241kJ/m²a), egestion (517.7302kJ/m²a), metabolism (38.3273 kJ/m²a), and excretion (4.3798kJ/m²a). The net growth efficiency of the species is about 22.7%, which accords well with the generally reported value for oligochaetes. In addition, the relationship between starvation respiration (R, mgO₂/ind·d), wet weight (Ww, mg) and temperature (T, °C) were also measured, with the regression function beingR=0.008Ww^0.736 e^0.050T. Project supported by NSFC (30270278, 3960019), the foundation of the government of Hubei Province (No. 2000J109), and the foundation of Ecological Station, CAS in the Institute of Hydrobiology.     

Reproductive rate of a marine planktonic copepodLabidocera euchaet a Giesbrecht in Xiamen Harbor

Reproductive rate of a marine planktonic copepodLabidocera euchaeta Giesbrecht in Xiamen Harbor bor was studied during the period from April 1986 to August 1987. Results showed that rate of egg production (F, eggs/(♀, d)) was positively correlated with temperature (T,^oC) and body weight of spawning female (Wc, μgC) as:F=0.0637 (T−7)^0.7445 Wc. Each month a maximum rate of egg production occurred at one of the five experimental temperatures (10°, 15°, 25°, and 30°C) near the monthly mean field temperature. The available food density (P, μgC/ml) had significant effect on specific rate of egg production (Fc, %C ♀/d) as:Fc=0.1732 (P-0.0179)/P. The gross efficiency of egg production of ca 62% in carbon was independent of food density snd ingestion rate. Observations on in situ egg production and hatching rate demonstrated that this species reproduces continuously all the year round, with summer as its high reproductive season and winter a low one. Ten generations a year is also suggested based on the number of the peaks of average population egg production rate. This agreed well with the result obtained from the generation-time equations. Egg-laying pattern was also observed and discussed.     

Effects of Body Weight and Water Temperature on Maximum Food Consumption of Juvenile Sebastodes fuscescens （Houttuyn）

Maximum rate of food consumption ( Cmax ) was determined for juvenile Sebastodes fuscescens (Houttuyn) at water temperature of 10, 15, 20 and 25℃. The relationships of Cmax to the body weight (W) at each temperature were described by a power equation: lnCmax = a b lnW. Covariance analysis revealed significant interaction of the temperature and body weight. The relationship of adjusted Cmax to water temperature (T) was described by a quadratic equation: Cmax = -0.369 0.456T - 0.0117T^2. The optimal feeding temperature calculated from this equation was 19.5 ℃. The coefficients of the multiple regression estimation relating Cmax to body weight (W) and water temperature (T) were given in the Table 2.     

Abundance and production ofBranchiura sowerbyi (Oligochaeta: Tubificidae) in two typical shallow lakes (Hubei, China)

An April 1996 to March 1997 comparative study on the abundance and secondary production ofBranchiura sowerbyi Beddard, 1892 in two typical shallow lakes showed that in Houhu, an algae-dominated lake, the worm density (68 ind·m⁻²) peaked in July, biomass (1.930 g·m⁻²) peaked in June, while in Biandantang, a macrophyte-dominated lake, standing stock (density: 60 ind·m⁻²; biomass: 1.019 g·m⁻² in wet weight) peaked in December. Secondary production of the animal in Houhu Lake was 3.413 g wet wt m⁻² a⁻¹, a little more than that (2.675 g wet wt m⁻² a⁻¹) in Biandantang Lake. Their turnover rates (P/B ratios) were 4.0 and 5.0, respectively. Project (39600019 and 39430101) supported by NSFC.     

THE DENSITIES OF CHANGJIANG ESTUARINE WATERS

The International Eq一lation of State of Seawater,1980 and the PraeticalSalinity Scale,1978 have been adoPted by theUNESCO江CES沼COR八APSOJoint Panel ono‘eanogral,hie Tables and Standards(JPOTS),and endorsed bythese organizati6ns(Miller‘〕and Poisson,1981;Uneseo,1981).Th已new equa-tion and the Praetieal Salinity Seale are to be used for all values Published fromJan .1,1982 .The new equation 15 aeeurate for use in all oeeanie surfaee waters,but eannot be aeeurately aPPlied to…     

DISCOVERY OF ORGANIC MOLECULES IN DEEP-SEA IRON COSMIC DUST

A great quartity of cosmic dust(spherules) was found in deep-sea sediments during May to July,1983manganese nodule investigations by the R/V“XIANGYANGHONG 16”in the area 7°-11°N,167°-178°Win the Pacific.Comprehensive study of the cosmic dust and determination with Laser Raman MolecularMicroprobe(LRMM) of the molecules in it showed that besides Fe-Fe,Fe~(3+)-O,Fe-Ni,Al-O,Fe-Obr-Si and Si-Onb,it also contained the organic molecules C-H-O and C-H-S-O,various no fixed form molecules of C,CH_2,CH_3 and volatile molecules CO_2,H_2O,OH~- and H_2S,etc…The study result has very important applications for exploring the origin of interplanetary dust parti-cles and life material.     

ENERGY FLOW OF BELIAMYA AERUGINOSA IN A SHALLOW ALGAL LAKE, HOUHU LAKE （WUHAN, CHINA）

The energy budget ofBellamya earuginosa in a shallow algal lake, Houhu Lake (Wuhan, China) was investigated by the measurement of flesh production (32.8 kJ/(m²·a)), egestion (337.7 kJ/(m²·a)), metabolism (246.7 kJ/(m²·a)), and estimation of excretion (21.4kJ/(m²·a)). The net growth efficiency of the species is about 10.9%, which accords with the generally reported value for gastropods. In addition, the relationships between starvation respiration (R, mgO₂/(Ind·d)), body weight (Wd, mg in dry wt) and temperature (T, °C) were also determined. The regression equationR=0.044Wd ^0.537 e ^0.061T was obtained by the least square method, The measured SDA of the species is 26.51% of its gross metabolism. Project No. 3960019 and 39430101 supported by NSFC and also a granted for the East Lake Ecological Experimental Station, CAS, Wuhan.     

Study on cryopreservation of Porphyra yezoensis conchocelis

Cryopreservation of Porphyra yezoensis conchocelis was conducted with cryoprotectants and a proposed pretreatment procedure and thawing methods explored. Six cryoprotectants combined by DMSO with ethylene glycol （EG）, propylene glycol （PEG）, sorbitol and sucrose were developed. The effect of prefreezing at -40℃ or -20℃ for different time durations was compared and the thawing methods were screened. It was shown that the cryoprotectant including 10% DMSO with 0.5 molL^-1 sorbitol exhibited the optimal effect. The ideal pretreatment was that conchocelis segments were stayed for 20min at -40℃ before stored in liquid nitrogen, and 40℃ water bath was proper for quick thawing. The highest recovery rate of cryopreserved P. yezoensis conchocelis reached 89.41%.     

Phosphorus budget of redeye mullet （Liza haematocheila T. ＆ S.） under graded feeding levels

Experiment on phosphorus budget of redeye mullet （Liza haematocheila T. ＆ S.） was conducted at water temperature 21℃ and salinity 33. The results showed that the growth phosphorus （phosphorus that allocated into growth, GP） increased from -30.84% to 15.83% by feeding on graded amount of diets （starvation, 1%, 2%, 3%, 4% body weight and satiation）. The GP linearly increased with feeding levels （FL） as GP （mg） = - 0.785 ＋ 0.604 FL, and at satiation the relationship between GP and body weight （BW） was GP （mg） = 1,5991 BW0.7685. In the budget, IP （intake phosphorus） = GP ＋ FP （faecal phosphorus） ＋ EP （excretion phosphorus）. FP showed an irregular tendency with different feeding levels, and EP decreased with increasing feeding levels but rebound at satiation. The P budget at satiation was 100IP = 15.84 GP ＋ 64.62 FP ＋ 19.55 EP.     

Cryopreservation of Gametophytes of Laminaria japonica （Phaeophyta） Using Encapsulation-Dehydration with Two-Step Cooling Method

Gametophytes of Laminaria japonica were cryopreserved in liquid nitrogen using encapsulation-dehydration with two-step cooling method. Gametophytes cultured at 10℃ and under continuous irradiance of 30 μmol m-2 s-1 for 3 weeks were encapsulated in calcium alginate beads. The beads were dehydrated in 0.4 molL-1 sucrose prepared with seawater for 6 h, desiccated in an incubator set at 10℃ and 70% relative humidity for 4 h, pre-frozen at either -40℃ or -60℃ for 30 min, and stored in liquid nitrogen for ＞24 h. As high as 43% of survival rate was observed when gametophytes were thawed by placing the beads in 40℃seawater and re-hydrated in 0.05 molL-1 citrate sodium prepared using 30‰ NaC1 7 d later. More cells of male gametophytes survived the whole procedure in comparison with female gametophytes. The cells of gametophytes surviving the preservation were able to grow asexually and produce morphologically normal sporophytes.     

Abundance and Biomass of Benthic Bacteria in Jiaozhou Bay, China

The abundance and biomass of benthic heterotrophic bacteria were investigated for the 4 typical sampling stations in the northern muddy part of Jiaozhou Bay, estuary of the Dagu River, raft culturing and nearby areas of Huangdao in March, June, August and December, 2002. The abundance and biomass range from 0.98×10⁷ to 16.87×10⁷ cells g⁻¹ sediment and 0.45 to 7.08 μg C g⁻¹ sediment, respectively. Correlation analysis showed that heterotrophic bacterial abundance and biomass are significantly correlated to water temperature (R=0.79 and 0.83, respectively,P<0.01).     

Size-fractionated phytoplankton biomass in autumn of the Changjiang （Yangtze） River Estuary and its adjacent waters after the Three Gorges Dam construction

A cruise was undertaken from 3rd to 8th November 2004 in Changjiang （Yangtze） River Estuary and its adjacent waters to investigate the spatial biomass distribution and size composition of phytoplankton. Chlorophyll-a （Chl-a） concentration ranged 0.42-1.17 μg L^-1 and 0.41-10.43 μg L^-1 inside and outside the river mouth, with the mean value 0.73 μg L^-1 and 1.86 μg L^-1, respectively. Compared with the Chl-a concentration in summer of 2004, the mean value was much lower inside, and a little higher outside the river mouth. The maximal Chl-a was 10.43 μg L^-1 at station 18 （122.67°E, 31.25°N）, and the region of high Chl-a concentration was observed in the central survey area between 122.5°E and 123.0°E. In the stations located east of 122.5°E, Chl-a concentration was generally high in the upper layers above 5 m due to water stratification. In the survey area, the average Chl-a in sizes of 〉20 μm and 〈20 μm was 0.28 μg L^-1 and 1.40 μg L^-1, respectively. High Chl-a concentration of 〈20 μm size-fraction indicated that the nanophytoplankton and picophytoplankton contributed the most to the biomass of phytoplankton. Skeletonema costatum, Prorocentrum micans and Scrippsiella trochoidea were the dominant species in surface water. The spatial distribution of cell abundance of phytoplankton was patchy and did not agree well with that of Chl-a, as the cell abundance could not distinguish the differences in shape and size of phytoplankton cells. Nitrate and silicate behaved conservatively, but the former could probably be the limitation factor to algal biomass at offshore stations. The distribution of phosphate scattered considerably, and its relation to the phytoplankton biomass was complicated.     

Effects of temperature and irradiance on early development of Chondrus ocellatus Holm (Gigartinaceae, Rhodophyta)

Chondrus is a type of commercially produced red seaweed that widely used for food and carrageen extraction. Although the natural life history of the alga had been well understood, the factors influencing development of the tetraspore and carpospore remain poorly understood. In the perspective of seedling resources, the regulation of early development is crucial for the seedling nursing; therefore, it is necessary to understand the physiological influences during its early development. In this study, we studied the effects of temperature and irradiance on the early development of Chondrus ocellatus Holm under laboratory conditions. The released tetraspores and carpospores were cultivated at different temperatures (10–28°C) and irradiances (10, 60 μmol photons m⁻²s⁻¹) with a photoperiod of 12L:12D. The results indicate that both tetraspores and carpospores are tolerant to temperatures of 10–25°C, and have the highest relative growth rate at 20°C. Irradiance variances influenced the growth of the discoid crusts, and the influence was more significant with increasing temperature; 60 μmol photons m⁻²s⁻¹ was more suitable than 10 μmol photons m⁻²s⁻¹. The optimum temperature and irradiance for the development of seedlings was 20°C and 60 μmol photons m⁻²s⁻¹, respectively.     

Relation of body weight and food consumption to metabolic rate of juvenile Japanese sea bass,Lateolabrax japonicus

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＪａｐａｎｅｓｅｓｅａｂａｓｓ (ＬａｔｅｏｌａｂｒａｘｊａｐｏｎｉｃｕｓＣ＆Ｖ)ｄｉｓｔｒｉｂｕｔｅｓｗｉｄｅｌｙｉｎｔｈｅｃｏａｓｔａｌｗａｔｅｒｓａｌｏｎｇｔｈｅＢｏｈａｉＳｅａ ,ＹｅｌｌｏｗＳｅａ ,ＥａｓｔＣｈｉｎａＳｅａ,ａｎｄＳｏｕｔｈＣｈｉｎａＳｅａ .Ａｓａｃａｒｎｉｖｏｒｏｕｓｆｉｓｈ ,ｉｔｏｃｃｕｐｉｅｓｔｈｅｈｉｇｈｔｒｏｐｈｉｃｌｅｖｅｌｉｎｔｈｅｍａｒｉｎｅｅｃｏｓｙｓｔｅｍａｎｄｈａｓａｄａｐｔｅｄｔｏｖａｒｉｏｕｓｅｎｖｉｒｏｎｍｅｎｔａｌｒ…     

ORGANIC GEOCHEMISTRY MARKERSOF CLIMATIC EVOLUTION IN LOESSREGION OF CHINA

Two hundred and thirty-five samples collected from Weinan loess section (L₂ – S₀) have been analyzed by TOC (total organic carbon) and pyrolysis hydrocarbons. The curve of TOC with depth has been set up and compared well with other climatic markers. The main periods of TOC variation of the last 0.14 Ma are 67.08 ka and 18.29 ka, which is near with the periods of the variation of sunshine, showing that the TOC variation may be controlled by the variation of 65°N sun-shine. The distribution of pyrolysis hydrocarbon and its parameters shows that there are two kinds of hydrocarbon associated with climatic change. One is called hydrocarbon pyrolysted directly from organism (pHC_2–1) which is in the range of T _max350°C – 500°C, and associated with atmospheric water. The other is called carbonate inclusion hydrocarbon (pHC_2–2) which is in the range of T _max 500°C – 600°C and formed by evaporation and associated with dry climate. The formula calculating humidity has been deduced Og=pHC_2–1/(pHC_2–1 + pHC_2–2). The range of humidity of the section is 47% – 77% and the reducing order is S_1–3, S_1–2, S₀, S_1–1, S_1–4, S_1–1, L_1–1, L_1–3, and L_1–5. And the trend of the humidity is still increasing today.     

Phytoplankton assemblage of Yangtze River Estuary and the adjacent east China sea in summer, 2004

A cruise was conducted from late August to early September 2004 with the intention of obtaining an interdisciplinary understanding of the Yangtze River Estuary including the biological, chemical and physical subjects. Water sample analysis indicated that total phytoplankton species richness was 137. Of them 81 were found in Bacillariophyta and 48 in Pyrrophyta, accounting for 59.1% and 35.0% respectively. The average cell abundance of surface water samples was 8.8×104 cells L-1, with the maximum, 102.9×104 cells L-1, encountered in the area (31.75°N, 122.33°E) and the minimum, 0.2×104 cells L-1, in (30.75°N, 122.17°E). The dominant species at most stations were Skeletonema costatum and Proboscia alata f. gracillima with the dominance of 0.35 and 0.27. Vertical distribution analysis indicated that obvious stratification of cell abundance and dominant species was found in the representative stations of 5, 18 and 33. Shannon-Wiener index and evenness of phytoplankton assemblage presented negative correlation with the cell abundance, with the optimum appearing in (30.75°N, 122.67°E). According to the PCA analysis of the environmental variables, elevated nutrients of nitrate, silicate and phosphate through river discharge were mainly responsible for the phytoplankton bloom in this area.