Effects of Temperature and Salinity on Oxygen Consumption Rate and Ammonia-N Excretion Rate of Red Apostichopus japonicus (Selenka)

Abstract:

The current study investigated the effects of temperature (7, 12, 17, 22, and 27℃) and salinity (23, 26, 29, 32, 35, and 38) on oxygen consumption rate (OCR) and ammonia-N excretion rate (AER) of small group (S) (1.68-3.48 g) and large group (L) (15.78-20.79 g) red Apostichopus japonicus. The results showed that temperature had significant effect on OCR and AER of red A. japonicus, and that body size significantly affected the AER but not OCR. There was significant interaction between body size and temperature (P<0.01). OCR and AER of S group was increased with the increasing of temperature; however, OCR and AER of L group were enhanced when temperature ranged from 7 to 17℃, and diminished at 22℃, and then increased at 27℃. Salinity and body size had significant effect on OCR and AER (P<0.05), and there was no significant interaction between body size and salinity (P<0.01). The effects of salinity on OCR and AER of two body groups of red A.japonicus showed a shape of ‘M’, which was lower at salinity of 29 and 32 and higher at salinity of 26 and 35. There is a negative regressive function R = aWb between the OCR/AER and body size. O:N ratios in different temperatures were covered range of 4.75-11.74 for S group and 10.71-15.52 for L group, respectively; O:N ratios in different salinities were covered range of 6.37-12.29 for S group and 8.24-12.10 for L group, respectively. These results demonstrated that the large group red type A. japonicus could not tolerate higher temperature and two group sea cucumbers were sensitive to lower and higher salinity. The study indicated that the optimum salinity range for red type A. japonicus was 29-32.