2.2.1.1 Temperature, salinity and dissolved oxygen
After extensive studies, several authors have mentioned certain physical, chemical and biological parameters of water and sediment as important for the aquaculture of marine shrimps. Along with dissolved oxygen, water temperature and salinity are considered as significant parameters because of their close association in aquatic ecosystem (OSPAR, 2005). The maximum water temperature recommended by Nunes et al., 2005 and ABBC, 2005 was 32°C, though the lower limit recommended by them varied slightly. Boyd (1990) suggests that 28-30°C is essential for the shrimp aquaculture. However, the optimal level mentioned by Chávez (2009) was 18° to 33°C. Water temperature along with salinity is dependent …show more content…
P. monodon is euryhaline with the ability to tolerate a wide range of salinity (1 to 57 ppt) (Chen, 1990). The optimum salinity suggested for L. vannamei culturing by Ferreira et al. (2011) is 15 ppt. The energy spent in osmoregulation will be minimal when aquatic organisms are reared in isosmotic solutions. Maintenance of optimum salinity was found to increase the tolerance of P. setiferus and P. schmitti post larvae to low oxygen concentration (Rosas et al., 1997). The ability of shrimps to tolerate variations in salinity depends on its developmental stage. Post larvae were found to be under osmotic stress and their oxygen consumption was more in higher salinities (Alvarez et al., 2004) whereas larger shrimps were found to tolerate lower salinities well (Bett and Vinatea, 2009). Though they may tolerate salinity changes, acute salinity variations, if they are coupled with poor water quality is stressful to shrimps (Brock and Main, 1994). In response to acute salinity changes, shrimps such as L. vannamei, produce reactive oxygen species (ROS) which damages its own cells. It has been shown that such cellular damage caused by salinity stress can be controlled by supplementing shrimp feed with Vitamin E (Liu et al., 2007a). As per studies, wide variation in temperature and salinity can compromise shrimp health leading to ion regulation stress (Lemaire et al., 2002; ABCC, 2005). Tendencia et al. (2010) have noted the combined role of water temperature, salinity and Vibrio count in the risk of WSSV infections in P. monodon in the Philippines. Salinity is an important factor which determines the survival of V. cholerae (Thomas et al., 2006), the newly emerging pathogen of P. monodon along the Cochin backwaters (Joseph et al.,, 2015a). Acute low salinity stress was found to affect the immunity of P. monodon and increased their susceptibility to WSSV (Joseph
After extensive studies, several authors have mentioned certain physical, chemical and biological parameters of water and sediment as important for the aquaculture of marine shrimps. Along with dissolved oxygen, water temperature and salinity are considered as significant parameters because of their close association in aquatic ecosystem (OSPAR, 2005). The maximum water temperature recommended by Nunes et al., 2005 and ABBC, 2005 was 32°C, though the lower limit recommended by them varied slightly. Boyd (1990) suggests that 28-30°C is essential for the shrimp aquaculture. However, the optimal level mentioned by Chávez (2009) was 18° to 33°C. Water temperature along with salinity is dependent …show more content…
P. monodon is euryhaline with the ability to tolerate a wide range of salinity (1 to 57 ppt) (Chen, 1990). The optimum salinity suggested for L. vannamei culturing by Ferreira et al. (2011) is 15 ppt. The energy spent in osmoregulation will be minimal when aquatic organisms are reared in isosmotic solutions. Maintenance of optimum salinity was found to increase the tolerance of P. setiferus and P. schmitti post larvae to low oxygen concentration (Rosas et al., 1997). The ability of shrimps to tolerate variations in salinity depends on its developmental stage. Post larvae were found to be under osmotic stress and their oxygen consumption was more in higher salinities (Alvarez et al., 2004) whereas larger shrimps were found to tolerate lower salinities well (Bett and Vinatea, 2009). Though they may tolerate salinity changes, acute salinity variations, if they are coupled with poor water quality is stressful to shrimps (Brock and Main, 1994). In response to acute salinity changes, shrimps such as L. vannamei, produce reactive oxygen species (ROS) which damages its own cells. It has been shown that such cellular damage caused by salinity stress can be controlled by supplementing shrimp feed with Vitamin E (Liu et al., 2007a). As per studies, wide variation in temperature and salinity can compromise shrimp health leading to ion regulation stress (Lemaire et al., 2002; ABCC, 2005). Tendencia et al. (2010) have noted the combined role of water temperature, salinity and Vibrio count in the risk of WSSV infections in P. monodon in the Philippines. Salinity is an important factor which determines the survival of V. cholerae (Thomas et al., 2006), the newly emerging pathogen of P. monodon along the Cochin backwaters (Joseph et al.,, 2015a). Acute low salinity stress was found to affect the immunity of P. monodon and increased their susceptibility to WSSV (Joseph