| 1. Effect of water temperature (7, 12, 17, 22 and 27°C) on oxygen consumption rates (OCR) and amomonia-N (AER) excretion rates of the green and the sea cucumbers (Apostichopus Japonicus) were studied in laboratory. The results were as follows: 1) Temperature had significantly effect on the oxygen consumption ratesand ammonium-N excretion rates for two groups of sea cucumber. The body weight was no significantly effect on red sea cucumbers, but was significantly effect on the green ones. There was significant interaction between temperature and size on OCR and AER for two groups of sea cucumber. There was significant difference between two groups sea cucumber of OCR at temperature of 7-22°C for the small group, while there was significant difference at temperature of 17-27°C for the large group. For the AER, there was significant difference between two groups sea cucumber at temperature of 7 and 27°C for small group, while was significant difference at temperature of 17-27°C for large group. 2) Under controlled temperature of 7-27°C, the regressive equation between body weight of sea cucumber and individual oxygen consumption rate (R,μg·g-1·h-1) is described as R = aWb, and the ranges of a and b values were 14.973-26.103, 0.425-1.03 for green ones, respectively; and 7.988-25.914, 0.755-1.141 for red ones, respectively. The regressive equation between body weight and individual ammonium-N excretion rate (R = aWb), the ranges of a and b values were 1.263-3.396, 0.411-0.941 for green ones, respectively; 0.713-2.723, 0.540-0.909 for red ones, respectively. 3) Temperature had no significant effect on O:N ratios (P>0.05), and the O:N ratios indicating that the green and red sea cucumbers in our testing conditions mainly utilized protein as its energy sources for the small size, while the percentage of lipid and carbohydrate increasing with the increase of body weight.2. Effect of salinity (23, 26, 29, 32, 35 and 38) on oxygen consumption rates and amomonia-N excretion rates of the green and the red sea cucumbers (Apostichopus Japonicus) were studied in the laboratory. The results were as follows: 1) Both of salinity and size had significantly effect on the oxygen consumption rate (OCR) and ammonium-N excretion rate (AER) for two groups of sea cucumber. There was no interaction between salinity and size on OCR and AER for two groups of sea cucumber. The OCR and AER were lowest at salinity of 29-32 for the green and the red sea cucumbers, and increased with the salinity changed to 35 and to 26, then declined at salinity of 23 and 38 again. The OCR of the green sea cucumber was higher than that the red ones at salinity range of 23-32, and lower than the red ones at salinity of 35-38. Whereas, the AER was higher than the red ones at salinity range of 23-29, and lower than the red ones at salinity of 32-38. 2) Under controlled salinity of 23-38, the regressive equation between body weight of sea cucumber and individual oxygen consumption rate (R,μg·g-1·h-1) is described as R = aWb, and the ranges of a and b values were 18.5963-24.980, 0.6393-0.913 for green ones, respectively; 10.5613-21.9678, 0.6393-0.913 for red ones, respectively. The regressive equation between body weight and individual ammonium-N excretion rate (R,μg·g-1·h-1) is described as R = aWb, and the ranges of a and b values were 18.5963-24.980, 0.6393-0.913 for green ones, respectively; 10.5613-21.9678, 0.8713-1.1023 for red ones, respectively. 4) O: N ratios were increased with salinity for the green sea cucumber indicating that the protein content of energy sources was increased; however, the O: N ratios were decreased with salinity for red sea cucumber indicating that the protein content of energy sources was decreased.3. The effect of light colors on the oxygen consumption rates (OCR) and ammonia-N excretion rates (AER) for the green and the red sea cucumber, Apostichopus japonicus, were examined at 16°C, and the five light colors were natural light (590nm), red light (700nm), yellow light (580nm), green light (525nm) and blue light (450nm), respectively. The results showed as followed: 1) There was significantly effect of light color on OCR for the green and the red sea cucumbers. The OCR at natural light was significantly higher than that at red and green light for the green sea cucumbers, and no difference was observed at different light color except at natural light. OCR at yellow light was significantly higher than that at natural light for the red group, and no difference was observed at different light color except at natural light. The OCR was significant differing at natural light between two groups of sea cucumbers. 2) There was significantly effect of light color on AER for the green and the red sea cucumbers. The AER at yellow light was significantly higher than that at green light for the green sea cucumber, and there was no difference among natural light, green light and red light. AER was highest at green light, and was lowest at natural light for the red sea cucumber. The AER was significant difference at natural light between two groups of sea cucumbers. The O: N ratios were less than 10, which indicated that the green and red sea cucumbers in our testing conditions mainly utilized protein as its energy sources.4. The effect of feeding on the oxygen consumption rate for the green and the red sea cucumbers, Apostichopus japonicus, was examined in a closed respiration chambers at 12, 16 and 20°C. Temperature had significant effect on the specific dynamic action (SDA) for the green and the red sea cucumbers. The results showed that the postprandial metabolic rate of sea cucumber displayed a general pattern, i.e., the specific dynamic action (SDA) peak occurred with 2-6 h, increased about 2-fold, and lasted 18-40 h. The basic metabolic rate, meal size and peak metabolic rate were no difference among temperatures and between two groups of sea cucumbers, which were no difference between 16°C and 20°C, but significant higher than that at 12°C. The SDA duration inversely related to temperature, but there was significant difference at various temperatures and no difference between green and red sea cucumbers. For the factorial metabolic scope, it was no differing at various temperatures, but those were significantly different at 12 and 16°C between green and red sea cucumbers, and no difference at 20°C. The magnitude of SDA was significantly different among various temperatures and groups of sea cucumbers. However, there was no difference for the SDA coefficient among various temperatures and groups of sea cucumbers.5. The present study examined the effects of diets on specific dynamic action (SDA) of green and red sea cucumbers, Apostichopus japonicus. The oxygen consumption rates (VO2) of the sea cucumbers fed with formulate diet (FMD), macroalgae (ALG) and sea mud (SMD) were measured in closed respiration chambers, and the SDA parameters, including peak VO2, factorial rise, duration and magnitude of SDA were calculated. It was found that A. japonicus exhibited a typical SDA response after feeding, where the metabolic rate increased soon after feeding, and reached the peak VO2 about 3 h, and then backed to the basic metabolism within SDA duration of 4.8-31.7 h according to the diets they were feeding. The meal ration and the time to reach peak metabolic rate were not affected by the diets and species (P > 0.05). The factorial rise was not different between FMD group and ALG group (P > 0.05), but they were significantly higher than those in SMD group (P < 0.05). The metabolic rate rose by up to about 2.1 times over the prefeeding value in the green sea cucumber ingesting FMD and ALG, and up to about 2.6 times in the red sea cucumber, whereas the factorial rise was average about 1.3 ingesting SMD for green and red groups of sea cucumber. The duration and magnitude of SDA was the highest in FMD group, followed by ALG group, and the lowest in SMD group, and there was significantly different in magnitude of SDA among diets for sea cucumbers.6. Compared studied the oxygen consumption and biochemical component of sea cucumber, Apostichopus japonicus, under the conditions of hibernation, aestivation and starvation. During the 36 d experimental period, no mortality was recorded. A. japonicus started hibernation or aestivation under the water temperature of < 3°C or > 20°C, showing feeding cessation and metabolic depression. The wet body weight of the control group increased by 18.5%, while the hibernation, aestivation and starvation groups decreased by 19.8%, 38.1% and 47.4%, respectively. The relationship of final wet body weight (BWt) to the initial wet body weight (BWo), temperature (T) and duration of starvation (D) of A. japonicus could be expressed as the regressive equation: BWt=82.102 + 0.662 BWo - 1.704T - 0.274D. The oxygen consumption rates of sea cucumber in hibernation and aestivation groups declined by 71.68% and 44.89%, respectively, while for the starvation group, the oxygen consumption rate declined by 48.92% compared with the initial day. Biochemical components of A. japonicus during hibernation, aestivation and starvation also showed significant change. Hibernation group catabolized lipid and carbohydrate as their main energy sources during the experimental period, and lipid and carbohydrate content declined by 26.2% and 63.8%, respectively. The protein content of starvation and aestivation groups decreased by 35.7% and 34.6%, respectively, indicating the utilization of protein as energy source. Meanwhile, lipid and carbohydrate content also decreased considerably for these 2 groups, especially for starvation group in which the lipid content declined by 33.6%. The results showed that the metabolic substrates of sea cucumber in stress groups were not only related to the duration of starvation and metabolic activity, but also related to the dormancy status. Therefore, in practical aquaculture of sea cucumber, lacking feed should be avoided and dormancy time should be shortening artificially. Feed with high protein and lipid content should be supplied before their dormancy to meet the metabolic and nutritional requirements of sea cucumber in dormancy.7. The growth and energy budget of young Apostichopus japonicus were studied under constant temperature of 7-27°C. The results showed that there was significantly effect of temperatures on the growth of A. japonicus (P<0.01). Specific growth rate (SGR) of the green sea cucumber increased from 0.359 %·d-1 at 7°C to 1.567 %·d-1 at 12°C and decreased to 0.36 %·d-1 at 27°C, while for the red one, the SGR increased from 1.049 %·d-1 at 7°C to 2.114 %·d-1 at 17°C and decreased to -0.323 %·d-1 at 27°C. The optimum temperature for the growth of the young green and the red sea cucumbers were 15.1°C and 16.3°C, respectively, calculated from the equation, which was derived from the relationship between SGR and temperatures. The apparent digestive rate (ADR) were lowest at 12°C and highest at 27°C for the green sea cucumber, while the ADR of the red ones were increasing with the temperature. The food conversion efficiency was deceasing with the temperature for two groups of sea cucumbers.The SGR-Salinity relation can be expressed as the following:Green SGRd = -0.0115 + 0.3467T - 0.6856T2 (R2=0.92, n=20)Red SGRd = -0.0139 + 0.4541T– 2.3117T2 (R2=0.867, n=20)The optimal salinity in terms of maximum growth was 15.1 and 16.3°C, respectively, calculated from the equations. The energy assimilated into metabolism and spent in feces as percentages of the energy from food were major factors that influenced the model of energy allocation. The metabolism as percentages of the energy from food increased with the increase of temperature and the growth energy decrease. The high growth rate for sea cucumber at higher temperature can be ascribing to the higher food consumption and lower metabolism rate.8. The growth and energy budget of the green and the red sea cucumbers, Apostichopus japonicus, were conducted under salinity of 23-38. The results showed that salinity had significantly effect on the growth of two groups of sea cucumbers. The specific growth rate (SGR) of the green sea cucumber was increasing with the salinity from 23 to 29 and decreased as the salinity increasing further. There was similar change of SGR for the red sea cucumber, but was grown fastest at salinity of 32. The SGR of the green sea cucumbers were significantly faster than the red ones at salinity of 23-32 and no difference was observed at salinity of 35-38. The apparent digestive rate (ADR) of the green sea cucumber was highest at salinity of 38 and lowest at 29, and changed from 33.46-39.94%. However, the red one of ADR was highest at salinity of 32 and lowest at 35, and changed from 38.87-42.79%. The ADR was higher at salinity between 23 and 38, but there was significant difference at salinity of 38. The trends of food conversion efficiency were similar to SGR, and were significantly different at salinity of 23-39 between the green and the red sea cucumbers. The SGR-Salinity relation can be expressed as the following: Green SGRd = -9.8181+0.7752S-0.0127S2 (R2=0.8199,n=24) Red SGRd = -11.617+0.8539S-0.0134S2 (R2=0.8593,n=24)The optimal salinity in terms of maximum growth was 29.6 and 31.86, respectively, calculated from the equations. The energy assimilated into feces and spent in metabolism as percentages of the energy form food were major factors that influenced the model of energy allocation. The former decreased with the increase of salinity and the latter increased. The energy budget of the green and the red sea cucumber did not have marked difference.9. The growth and energy budget of young Apostichopus japonicus were studied under five light colors. The results showed that light colors had significantly effect on the growth of two groups of sea cucumbers. 1) The specific growth rate (SGR) of green group under different light color was as follows: yellow > natural > blue > red > green, and for the red group was yellow > red > natural > blue > green. The SGR for the green sea cucumber was lower 19.62%, 58.68% and 10.50% under red light, green light and blue light compared with natural light, respectively. While for the red sea cucumber, the SGR was higher 22.57% under yellow light, and lower 27.07% and 13.52% under green and red light compared with natural light, respectively. 2) The minimal feed intake (FI) was under green light for the green group sea cucumber, and FI was not observed under different light color for the red group sea cucumber. The apparent digestive rate (ADR) was lowest under yellow light and highest under red light for green and red sea cucumber, respectively, and was no significant difference at other light color. The food conversion rate was lowest at green light for both of green and red sea cucumber. 3) Since the energy assimilated into feces and spent in metabolism as percentages of the energy form food were major factors that influenced the model of energy allocation, the energy allocation under five light colors was different. The growth energy to energy from food for green and red sea cucumber were highest under yellow light, however, the metabolism energy o energy from food was lowest for green sea cucumber and was highest for red sea cucumber.
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