Effect of salinity on survival, growth, oxygen consumption and ammonia-N excretion of juvenile whiteleg shrimp,Litopenaeus vannamei

Abstract

In this study, we tested the lower salinity tolerance of juvenile shrimps (Litopenaeus vannamei) at a relatively low temperature (20 1C). In the ¢rst of two laboratory experiments, we ¢rst abruptly transferred shrimps (6.91 AE 0.05 g wet weight, mean AE SE) from the rearing salinity (35000 mg L À 1 ) to salinities of 5000, 15000, 25000, 35000 (control) and 40 000 mg L À 1 at 20 1C. The survival of L. vannamei juvenile was not a¡ected by salinities from 15000 to 40 000 mg L À 1 during the 96-h exposure periods. Shrimps exposed to 5000 mg L À 1 were signi¢cantly a¡ected by salinity, with a survival of 12.5% after 96 h. The 24-, 48-and 96-h lethal salinity for 50% (LS 50 ) were 7020,8510 and 9540 mg L À 1 respectively. In the second experiment, shrimps (5.47 AE 0.09 g wet weight, mean AE SE) were acclimatized to the different salinity levels (5000, 15000, 25000, 35000 and 40 000 mg L À 1 ) and then maintained for 30 days at 20 1C. Results showed that the survival was signi¢cantly lower at 5000 mg L À 1 than at other salinity levels, but the ¢nal wet weight under 5000 mg L À 1 treatment was signi¢cantly higher than those under other treatments (Po0.05). Feed intake (FI) of shrimp under 5000 mg L À 1 was signi¢cantly lower than those of shrimp under 150 004 0 000 mg L À 1 ; food conversion e⁄ciency (FCE), however, showed a contrasting change (Po0.05). Furthermore, salinity signi¢cantly in£uenced the oxygen consumption rates, ammonia-N excretion rates and the O/N ratio of test shrimps (Po0.05). The results obtained in our work provide evidence that L. vannamei juveniles have limited capacity to tolerate salinities o10 000 mg L À 1 at a relatively low temperature (20 1C). Results also show that L. vannamei juvenile can recover from the abrupt salinity change between 15000 and 40 000 mg L À 1 within 24 h. Low salinity and temperature a¡ected survival of whiteleg shrimp P Zhang et al. Low salinity and temperature a¡ected survival of whiteleg shrimp P Zhang et al. Low salinity and temperature a¡ected survival of whiteleg shrimp P Zhang et al. Low salinity and temperature a¡ected survival of whiteleg shrimp P Zhang et al.

Physiological change and nutritional requirement of Pacific white shrimpLitopenaeus vannameiat low salinity

“…In another study, the growth rate of L. vannamei at 10 or 28 psu was also significantly higher than at 2 psu, but no growth difference was between 10 and 28 psu (Walker et al 2009 final weight was obtained at 5 and 15 psu, which significantly differed from those of shrimp at the salinity >25 psu, there was no significant difference between the final weights at 5 and 15 psu possibly due to short experimental duration (Bray et al 1994). Similarly, when shrimp were acclimatized to different salinities (5,15,25,35 or 40 psu), the survival was significantly lower at 5 psu than at other salinities, but the final wet weight was significantly higher than those at salinities exceeding 5 psu after 30 days (Zhang et al 2009). As the maintenance of internal ionic homeostasis, normal cellular function and other physiological processes in aquatic animals requires more energy, further more energy may require for osmoregulation at low salinity, leading to less energy for shrimp growth (Li et al 2008a).…”

“…Similarly, when shrimp were acclimatized to different salinities (5, 15, 25, 35 or 40 psu), the survival was significantly lower at 5 psu than at other salinities, but the final wet weight was significantly higher than those at salinities exceeding 5 psu after 30 days (Zhang et al . ).…”

“…; Zhang et al . ). When the effects of salinity and acclimation time on juvenile L. vannamei were evaluated based on oxygen consumption, and the L. vannamei could well adapt to a sudden change in salinity or acclimation to a gradual change of ambient salinity, and the fasting and feeding oxygen consumptions increased with the decrease of salinity with the highest value of oxygen consumption detected at 5 psu (Rosas et al .…”

“…On the contrary, the oxygen consumption of L. vannamei at 5 psu was significantly lower than at 15, 25, 35 or 40 psu at 20 °C (Zhang et al . ).…”

Growth performance, haematological parameters, antioxidant status and salinity stress tolerance of juvenile Pacific white shrimp (Litopenaeus vannamei ) fed different levels of dietary myo -inositol

“…Although shrimp are well adapted to cope with environmental changes, such as salinity, temperature, dissolved oxygen and pH changes (Brito, Chimal, & Rosas, ; Castille & Lawrence, ; Chen & Lai, ; Rosas et al. ; Spaargaren, Richard, & Ceccaldi, ; Zhang, Zhang, Li, & Gao, ), these changes are still stressful for the shrimp, and radicals generated from acute stress may result in oxidative stress or even mortality (Le Moullac & Haffner, ; Liu, Wang, Wang, Wang, & Sun, ; Wang & Chen, ). Moreover, previous studies reported that changes in salinity might be noxious to L. vannamei and olive flounder due to enhancement of reactive oxygen species (ROS) generation, inducing oxidative stress (Choi, An, & An, ; Liu et al., ).…”