Rates of oxygen consumption and tolerance of hypoxia and desiccation in Chinese black sleeper(Bostrichthys sinensis)and mudskipper(Boleophthalmus pectinirostris)embryos

The rates of oxygen consumption, tolerance of hypoxia and desiccation of the Chinese black sleeper （ Bostrichthys sinensis） and mudskipper （Boleophthalmus pectinirostris） embryos were investigated. The pattern of oxygen consumption of the Chinese black sleeper embryos was similar to that of the mudskipper ones. The lowest rates of oxygen consumption [ （ 1.65 ±0. 66） nmol/ （ind. ·h） ] of the Chinese black sleeper embryos 16 h after fertilization and the lowest rates of oxygen consumption [ （0.79± 0.08 ）nmolf（ ind. · h） ] of the mudskipper embryos 6 h after fertilization were recorded, respectively. Then the rates of oxygen consumption of these two species embryos increased gradually until hatching [ （8.26 ± 1.70 ） nmolf（ ind.· h） in the Chinese black sleeper, （2.69 ± 0.23 ）nmolf（ ind. · h） in mudskipper]. After exposure to hypoxia water （0.16 mg/dm^3）, bradycardia of the embryos occurred in both the Chinese black sleeper and the mudskipper. However, the Chinese black sleeper embryos survived approximately 45 min longer than the mudskipper ones. After exposure to desiccation at a relative humidity of 58%, bradycardia of the embryos was observed in both the Chinese black sleeper and the mudskipper, and the Chinese black sleeper embryos lived approximately 9 min longer than the mudskipper ones.

EFFECTS OF TEMPERATURE AND DISSOLVED OXYGEN CONTENT ONOXYGEN CONSUMPTION RATE OF CHINESE PRAWN, GIANT TIGER PRAWN AND GIANT FRESHWATER PRAWN

temperature and the diasolved oxygen content affect the oxygen consumption of juveniles of Chinese prawn (Penaeus chinensis), giant tiger prawn (P. monodon) and giant freshwater prawn(Macrobrachium rosenbergii). There is good correlation between the oxygen consumption rate (V, mg/g·h) of the above three prawn species and the water temperature, and dissolved oxygen. In the range of test temperature, V increased with water temperature and diassolved oxygen content. The V of the above three prawn species increased 0.085 mg/g·h, 0. 093 mg/g·h and 0. 08 mg/g·h respectively with each ℃ of rising temperature. The comatose point and stifling point of the juveniles rose obviously at unsuitable temperature.

Determining oxygen consumption rate and asphyxiation point in Chanodichthys mongolicus using an improved respirometer chamber

Knowledge of oxygen consumption rates and asphyxiation points in fish is important to determine appropriate stocking and water quality management in aquaculture. The oxygen consumption rate and asphyxiation point in Chanodichthys mongolicus were detected under laboratory conditions using an improved respirometer chamber. The results revealed that more accurate estimates can be obtained by adjusting the volume of the respirometer chamber, which may avoid system errors caused by either repeatedly adjusting fish density or selecting different equipment specifications. The oxygen consumption rate and asphyxiation point of C. mongolicus increased with increasing water temperature and decreasing fish size. Changes in the C. mongolicus oxygen consumption rate were divided into three stages at water temperatures of 11-33~C： （I） a low temperature oxygen consumption rate stage when water temperature was 11-19~C, （2） the optimum temperature oxygen consumption rate stage when water temperature was 19-23~C, and （3） a high temperature oxygen consumption rate stage when water temperature was 〉27~C. The temperature quotients （Q10） obtained suggested that C. mongolicus preferred a temperature range of 19-23~C. At 19~C, C. mongolicus exhibited higher oxygen consumption rates during the day when the maximum values were observed at 10：00 and 14：00 than at night when the minimum occurred at 02：00.

Effects of Temperature and Salinity on Oxygen Consumption and Ammonium Excretion Rate of ♀ Epinephelus fuscoguttatus × ♂ E. lanceolatus Juveniles

The impact of water temperature(24, 27, 30 and 33℃) and salinity(15, 20, 25, 30 and 33) on oxygen consumption(OCR) and ammonium excretion rate(AER) of ♀ Epinephelus fuscoguttatus ×♂ E. lanceolatus hybrid grouper juveniles(9.39 ± 0.07 g) were investigated under the fed and un-fed conditions. The results showed that the OCR and AER were significantly(P < 0.05) affected by temperature and salinity under both fed and un-fed conditions. When temperature was 24–33℃, the OCR and AER of fed hybrid grouper juveniles were 85.68%–129.52% and 125.78%–287.63%, respectively, higher than those of un-fed hybrid grouper juveniles. The O/N ratio, protein use(P_u), Q_(10)(respiration) and Q_(10)(excretion) of fed hybrid grouper juveniles were 14.43–24.01, 28.35% – 48.48%, 1.69 and 3.01, respectively. The O/N ratio, P_u, Q_(10)(respiration), Q_(10)(excretion) of un-fed hybrid grouper juveniles were 20.39 – 31.79, 22.16% – 34.34%, 1.23 and 1.17, respectively. When salinity was 15–33, the OCR and AER of fed hybrid grouper juveniles increased by 87.42% – 116.85% and 215.38% – 353.57%, respectively, over those of un-fed hybrid grouper juveniles. The O/N ratio and P_u of fed hybrid grouper juveniles were 14.48 – 17.78, 39.36% – 49.43%, respectively. The O/N ratio and Pu of un-fed hybrid grouper juveniles were 20.39 – 31.79 and 22.16% – 34.34%, respectively. The specific dynamic action(SDA) of hybrid grouper juveniles was mainly related to protein metabolism. The results had a guiding significance to the large-scale intensive aquaculture of hybrid grouper juveniles.

An innovative method to calculate oxygen consumption rate

Based on heat and mass transfer characteristics of spontaneous combustion of coal,Arrhenius equation and the Ranz-Marshall correlation,a novel approach was proposed in this paper to estimate oxygen consumption rate of self-ignition of coal at high temperature.Compared with the conventional methods,this approach involves not only kinetic properties of self-ignition of coal and temperature,but also the ambient air flow characteristics and diameter of coal particle.To testify the proposed approach,oxygen consumption rates at high temperature were measured by the programmable isothermal oven experiments.Comparisons between experimental and theoretical results indicate that the rates of oxygen depletion calculated by the proposed approach agree well with those measured from laboratory-scale experiments,which further validates the proposed approach.

Direct measurement of oxygen consumption rates from attached and unattached cells in a reversibly sealed, diffusionally isolated sample chamber

Oxygen consumption is a fundamental component of metabolic networks, mitochondrial function, and global carbon cycling. To date there is no method available that allows for replicate measurements on attached and unattached biological samples without compensation for extraneous oxygen leaking into the system. Here we present the Respiratory Detection System, which is compatible with virtually any biological sample. The RDS can be used to measure oxygen uptake in microliter-scale volumes with a reversibly sealed sample chamber, which contains a porphyrin-based oxygen sensor. With the RDS, one can maintain a diffusional seal for up to three hours, allowing for the direct measurement of respiratory function of samples with fast or slow metabolic rates. The ability to easily measure oxygen uptake in small volumes with small populations or dilute samples has implications in cell biology, environmental biology, and clinical diagnostics.

Effect of Fouling on Feeding, Oxygen Consumption and Waste Excretion of Pearl Oyster Pinctada martensii in Daya Bay Cultivation

Biofouling is a particular problem in the pearl oyster culture. It may reduce the growth and survival rates of the cultured species. Foulers are often themselves filter feeders, and are therefore potential competitors for food resource with the cultured species. Fouling organisms may also reduce the oxygen supply. A study was conducted to measure the impact of foulers on feeding oxygen consumption, and waste excretion. POM, ammonia, phosphate and oxygen concentration were measured in various treatments （cultured species, foulers）. This study showed that fouling organisms had significant effect on food uptake, oxygen consumption and waste excretion. The clearance rate, ammonia and phosphate release rate, oxygen consumption rate of the fouled pearl oyster were greater than those of the clean pearl oysters. Other foulers that settled on cages or buoys also contributed much to phytoplankton depletion, oxygen consumption and concentration increase of ammonia and phosphate in water. Therefore, this study showed us that foulers were important competitors in the pearl oyster cultivation of Daya Bay in November 2005.

Oxygen consumption and ammonia-N excretion of Meretrix meretrix in different temperature and salinity

Effects of temperatures and salinities on oxygen consumption and ammonia-N excretion rate of clam Meretrix meretrix were studied in laboratory from Oct. 2003 to Jan. 2004. Two schemes were designed in incremented temperature at 10, 15, 20, 25℃ at 31.5 salinity and in incremented salinity at16.0, 21.0, 26.0, 31.5, 36.0, and 41.0 at 20℃, all for 8-10 days. From 10 to 25℃, both respiration and excretion rate were increased. One-way ANOVA analysis demonstrated significant difference （P〈0.01） in physiological parameters in this temperature range except between 15 and 20℃. The highest Q10 thermal coefficient value （12.27） was acquired between 10 and 15℃, and about 1 between 15 and 20℃, indicating M. meretrix could well acclimate to temperature changes in this range. Salinity also had significant effects on respiration and excretion rate （P〈0.05）. The highest values of respiration and excretion rate of M. meretrix were recorded at 16.0 salinity （20℃）. These two physiological parameters decreased as salinity increased until reached the minimum Q10 value at 31.5 （20℃）, then again, these parameters increased with increasing salinity from 31.5 to 41.0. M. meretrix can catabolize body protein to cope with osmotic pressure stress when environmental salinity is away from its optimal range. No significant difference was observed between 26.0 and 36.0 in salinity （P〉0.05）, suggesting that a best metabolic salinity range for this species is between 26.0 and 36.0.

The Effect of Toxic Sulfide Exposure on Oxygen Consumption and Oxidation Products in Urechis unicinctus(Echiura:Urechidae)

To investigate sulfide detoxification in Urech＆ unicinctus, oxygen consumption rate and sulfide detoxification products were analyzed during sulfide exposure under controlled laboratory conditions. The results showed that oxygen consumption rates were elevated significantly during 3 h sulfide exposure compared to the control （P〈0.05）. The concentration of sulfite in body wall and hindgut of experimental worms increased significantly （P〈0.05） when exposed to 50 μmolL^-1 sulfide, reached a maximum at 24 h and then decreased. Similar result was observed in worms exposed to 150 μmolL^-1 sulfide except that sulfite concentration reached a maximum at 12 h. Contents of thiosulfate in body wall and hindgut of U. unicinctus exposed to sulfide were also significantly higher than that of the control without sulfide exposure. In conclusion, during short-time sulfide exposure U. unicinctus may raise oxygen consumption to detoxify toxic sulfide into sulfite and thiosulfate. Sulfide detoxification was restrained when the exposure time was prolonged or sulfide concentration was increased, which was indicated by decrease of sulfite, the intermediate product of sulfide detoxification.

EFFECTS OF REDUCED SALINITY ON OXYGEN CONSUMPTION AND AMMONIA-N EXCRETION OF CHLAMYS FARRERI

Effects of reduced salinity on the oxygen consumption rate (OCR) and the ammonia N excretion rate (AER) of scallop Chlamys farreri (3.2 5.9 cm in shell height, 0.147 1.635 g in soft tissue dry weight ) were studied in laboratory from March 21,1997 to April 16, 1997. Under the controlled conditions of reduced salinity from 31.5 to 15.0 and ambient temperature 17℃ and 23℃, the concentrations of dissolved oxygen and ammonia N were determined by the Winkle method and the hypobromite method, respectively. Results showed that with controlled reduced salinity, the mean values of the OCR were 2.17 mg/(g.h) at 17℃, and 2.86 mg/(g.h) at 23℃and that the mean values of the AER were 178.0 μg/(g.h) at 17℃ and 147.0 μg/(g.h) at 23℃. The OCR and the AER decreased with reducing salinity from 31.5 to 15.0 both at 17℃ and 23℃. The effects of reduced salinity on the OCR and the AER of scallop C. farreri could be represented by the allometric equation and the exponential equation, respectively.

Study on Oxygen Consumption of Erinaceus europaeus under Laboratory Conditions

[Objective]The study aimed to determine oxygen consumption of Erinaceus europaeus at different temperatures to accumulate basic da- ta for the protection and deep discuss of Erinaceus europaeus. [Method]By using the improved close respiration apparatus,the time spent by ani- mals consuming a unit volume of oxygen was recorded by the improved close respiration apparatus to estimate oxygen consumption of Erinaceus europaeus at 20,25 and 30 °C respectively. [Result]When the temperature varied from 20 to 30 °C,the oxygen consumption and oxygen con- sumption rate of Erinaceus europaeus reduced with the increase of external temperature on the whole. The weight of Erinaceus europaeus had no obvious relation with its oxygen consumption and oxygen consumption rate. In addition,the temperature had linear regression relationships with the oxygen consumption and oxygen consumption rate of Erinaceus europaeus,that is,the linear regression equation between oxygen consumption （ x 0 ） （ ml/h） and temperature （ t） was x 0 =658. 81 -14. 98t,and the equation between oxygen consumption rate （ Q 0 ） [L/（ kg·h） ]and tempera- ture （ t） was Q 0 =827. 94 -19. 52t. [Conclusion]The metabolic rate of Erinaceus europaeus changed with environmental temperature,and 20 °C was more suitable for its growth,conforming with the fact that it is active just at night.

EFFECTS OF TEMPERATURE ON OXYGEN CONSUMPTION AND AMMONIA EXCRETION BY SOLENAIA OLEIVORA

The effects of water temperature on oxygen consumption rate and ammonia excretion rate of Solenaia oleivora were studied in the laboratory. The results showed that, under controlled conditions and ambient temperatures 15—30℃, the relationship between oxygen consumption rate (O) [mg/h] and dry weight of soft tissue (W) [g] can be represented by an allometric equation O=aW b, while the relationship between ammonia excretion rate (N) [μg/h] and dry weight of soft tissue (W) [g] follows also an allometric equation N=cW b. It is indicated that both metabolic rates are correlated positively with water temperature. High temperature can reduce the level of protein metabolism. The linear regression among oxygen consumption rate (O), temperature (T) and dry weight of soft tissue (W) can be described by the equation O=-0.6513+0.0532T+0.1073W, and for ammonia this relation is N=32.1626-1.0566T+1.3222W, the multiple relation coefficient was 0.9642 and 0.8921, respectively.

EFFECTS OF TEMPERATURE ON OXYGEN CONSUMPTION AND AMMONIA-N EXCRETION OF CHLAMYS FARRERI

of temperature on oxygen consumption rate (OCR) and ammonia-N excretion rate of scallop Chlamys farreri (1.7-6.2 cm in shell height) were studied in laboratory from Dec. 30 1996 to Jan. 28, 1997 . Under the controlled conditions of ambient water temperature 10-31℃ and salinity 32, the concentrations of dissolved oxygen and ammonia-N were determined by the Winkle method and the hypobromite method , respectively . Results showed that the OCR ranged from 1.20 mg/g (DW). h to 5.76mg/g (DW). h. The OCR increased with temperature from 10℃ to 23℃, but at 28℃ the OCR of mature individuals decreased, and that of different size scallops reduced at 31℃. The ammonia-N excretion rate ranged from 113.13 μg NH4-N/g (DW). h to 486.63 μg NH4 -N/g (DW). h,and increased with temperature from 10℃ to 31℃.

Effect of temperature on the standard metabolic rates of juvenile and adult Exopalaemon carinicauda

Ridgetail white prawn （Exopalaemon carinicauda） are of significant economic importance in China where they are widely cultured. However, there is little information on the basic biology of this species. We evaluated the effect of temperature （16, 19, 22, 25, 28, 31, and 34℃） on the standard metabolic rates （SMRs） of juvenile and adult E. carinicauda in the laboratory under static conditions. The oxygen consumption rate （OCR）, ammonia-N excretion rate （AER）, and atornic ratio of oxygen consumed to nitrogen consumed （O：N ratio） of juvenile and adult E. carinicauda were significantly influenced by temperature （P〈0.05）. Both the OCR and AER of juveniles increased significantly with increasing temperature from 16 to 34℃, but the maximum OCR for adults was at 31℃. Juvenile shrimp exhibited a higher OCR than the adults from 19 to 34℃. There was no significant difference between the AERs of the two life-stages from 16 to 31 ℃ （P〉0.05）. The O：N ratio in juveniles was significantly higher than that in the adults over the entire temperature range （P〈0.05）. The temperature coefficient （Q_10） of OCR and AER ranged from 5.03 to 0.86 and 6,30 to 0.85 for the adults, respectively, and from 6,09-1.03 and 3.66-1.80 for the juveniles, respectively. The optimal temperature range for growth of the juvenile and adult shrimp was from 28 to 31℃, based on Q_10 and SMR values. Results from the present study may be used to guide pond culture production ofE. carinicauda.

不同预氧化温度破碎煤在轴压下的自燃特性

目的为了探究采空区破碎煤在应力状态下的氧化自燃特性,方法采用荷载加压煤自燃特性参数测定装置,研究不同预氧化温度破碎煤在不同轴压状态下的自燃特性,分析破碎煤在氧化过程的耗氧速率、特征温度点、气体生成和表观活化能等特征参数变化规律。结果结果表明:轴压会增强煤的自燃特性,具体表现为耗氧速率增加,CO和C_(2)H_(4)气体体积分数增大,氧化特征温度点前移,表观活化能减小;轴压为0,4 MPa时,预氧化温度70℃煤样的氧化特性最强,轴压为8 MPa时,预氧化温度升高导致煤样的氧化特性降低;结合耗氧速率、指标气体和表观活化能的变化,表明预氧化温度70℃的煤自燃倾向性更高,更易复燃。结论(1)不同预氧化温度煤样的自燃特性在轴压的影响下表现一致:轴压会增强煤的氧化特性,更容易到达快速氧化阶段。(2)不同轴压下预氧化温度对煤样的自燃特性影响存在差异:预氧化温度升高反而会降低煤样的氧化特性,表明在高轴压影响下煤体预氧化温度越高,其氧化特性越弱。

拼装湿地循环处理对城市水体水质改善的效果

近年来,降雨径流造成城市水体有机物和氨氮浓度超标的微污染问题较为突出,影响城市人居与生态环境,亟需开发绿色高效的原位处理技术以满足微污染城市水体水质改善需求。选取城市雨水提升泵站前池为处理水体,在水体内原位设置由动力模块和高效模块组成的循环拼装湿地,通过泵站前池水体循环处理方式,去除水体污染物和提升水体自净能力;通过对拼装湿地不同模块运行水质参数〔化学需氧量(COD)、氨氮、浊度〕的连续监测及水体不同区域耗氧速率和氨氮消除速率测定,探究拼装湿地循环处理对城市微污染水体水质改善的影响。结果表明:1)拼装湿地能够稳定去除约85%的COD和87%的氨氮,水体COD和氨氮浓度分别稳定在2~3和0.2~0.3 mg/L;2)拼装湿地循环处理作用下,泵站前池水体的耗氧速率提升3~10倍,氨氮去除速率提升2~3倍;3)拼装湿地填料表面形成了具有高效脱氮除碳功能的微生物种群,保证了拼装湿地良好的污染物去除性能。拼装湿地循环处理方式不仅借助设备本身的过滤、植物吸收和微生物降解等过程去除污染物,还通过强化气液传质、提升溶解氧水平和提高生化反应速率等方式提升了所处理水体的自净能力。拼装湿地循环处理技术在净化城市河湖水体、改善水体微生态等方面具有推广应用的潜力。

不同预氧化程度下煤自燃特性研究

煤自燃是影响煤矿安全生产的主要灾害之一。为研究氧化煤的自燃特性,利用程序升温试验系统对预氧化不同氧化程度为40℃、70℃、100℃、120℃、150℃和170℃煤样在低温氧化阶段的耗氧速率、CO和CO_(2)产生率、放热强度进行了计算,得出不同氧化程度煤在不同氧化温度下的自燃特性。结果表明:随着温度的升高,预氧化程度为40℃、70℃、100℃、120℃、150℃和170℃煤样的耗氧速率、CO及CO_(2)产生率、放热强度均超过了原煤,预氧化程度为170℃的煤样与原煤基本持平,对氧化煤应该进行有效防治,分析结果对采空区煤自燃防治具有一定的指导意义。

Metabolic rates and biochemical compositions of Apostichopus japonicus (Selenka) tissue during periods of inactivity

Estivation, hibernation, and starvation are indispensable inactive states of sea cucumbers Apostichopusjaponicus in nature and in culture ponds. Generally, temperature is the principal factor that induces estivation or hibernation in the sea cucumber. The present study provided insight into the physiological adaptations ofA. japonicus during the three types of inactivity （hibernation, estivation, and starvation） by measuring the oxygen consumption rates （Vo2） and biochemical compositions under laboratory conditions of low （3℃）, normal （17℃） and high （24℃） temperature. The results show that the characteristics of A. japonicus in dormancy （hibernation and estivation） states were quite different from higher animals, such as fishes, amphibians, reptiles, and mammals, but more closely resembled a semi-dormant state. It was observed that the shift in the A. japonicus physiological state from normal to dormancy was a chronic rather than acute process, indicated by the gradual depression of metabolic rate. While metabolic rates declined 44.9% for the estivation group and 71.7% for the hibernation group, relative to initial rates, during the 36 d culture period, metabolic rates were not maintained at constant levels during these states. The metabolic depression processes for sea cucumbers in hibernation and estivation appeared to be a passive and an active metabolic suppression, respectively. In contrast, the metabolic rates （128.904-11.70 μg/g h） of estivating sea cucumbers were notably higher （107.85±6.31 μg/gh） than in starving sea cucumbers at 17℃, which indicated that the dormancy mechanism here, as a physiological inhibition, was not as efficient as in higher animals. Finally, the principle metabolic substrate or energy source of sea cucumbers in hibernation was lipid, whereas in estivation they mainly consumed protein in the early times and both protein and lipid thereafter.

THE DISTRIBUTION PATTERNS OF BACTERIA,ATP AND THE RELATIONS WITH RESPIRATION RATES AND PHYTOPLANKTON IN THE CHANGJIANG ESTUARY AND ITS ADJACENT EAST CHINA SEA

Two cruises were conducted in January and July 1986 in the Changjiang (Yangtse River) Estuary and its adjacent East China Sea (30°45′ -32°00′N,121°00′-124°00′E). Direct epifluorescence counts of planktonic bacteria and determinations of ATP concentrations were made. Subsamples were taken for measurement of oxygen consumption rates and chlorophyll concentrations.Bacteria and ATP concentrations were higher in summer than in winter, highest in the river and the river mouth, and gradually lower offshore. The bacteria number was correlated positively with suspended matter, nitrates and oxygen consumption rates, and negatively with salinity.In winter bacteria were the main contributors of ATP and the main consumers of dissolved oxygen in the whole studied area. In summer two maxima of ATP were found along the salinity gradient. The first one which coincided with the peak of turbidity near the river mouth was attributed to bacte -ria, and the second which occurred in the waters with a salinity range

STUDY ON THE DISSOLVED OXYGEN FLUX IN THE SOUTH CHINA SEA

The seawater box model for the South China Sea (SCS) was used to calculate the fluxes of dissolved oxygen in Box I, Box Ⅱand Box Ⅲ for establishing the box model of dissolved oxygen (DO)in the SCS.The total input flux of oxygen to the SCS was calculated to be 280.4×104 mol/s, of which 49.2% was transported into the sea by outer oceans, 30.3% came from organisms photosynthesis, 3% from rainfall, 0.4% from rirers, and 17.0% from the atmosphere.