Acclimation of Litopenaeus vannamei Postlarvae to Low Salinity: Influence of Age, Salinity Endpoint, and Rate of Salinity Reduction

Abstract

Abstract.— Inland culture of Liropenaeus vannarnei in low salinity well waters is currently conducted on a small scale in a few areas in the U.S. To successfully rear shrimp in low salinity water, postlarvae (PL) must be transferred from high‐salinity larval rearing systems to low‐salinity growout conditions. To determine effective transfer methods, a series of experiments were conducted under controlled conditions to evaluate the influence of PL age, rate of acclimation, and salinity endpoint on 48 h survival of shrimp. Three age classes of L. vannurnei PL (10, 15, and 20‐d) were acclimated from a salinity of 23 ppt to treatment endpoint salinities of 0, 1, 2, 4, 8, and 12 ppt. Survival of PL10 acclimated to 0, 1, or 2 ppt salinity was significantly lower than survival of PL acclimated to salinities of 4, 8, and 12 ppt. Survival of PL, and PL20 shrimp was only reduced for the 0 ppt salinity treatment, thus indicating a clear effect of age on salinity tolerance. The same age classes of PL were acclimated from 23 ppt to final salinity endpoints of I or 4 ppt at three different rates of salinity reduction: low, 19%/h; medium, 258/h, and high, 478/h. Survival was not significantly influenced by the acclimation rates for any of the three PL age classes. As in the fixed rate experiments, survival of the 10‐d‐old PL was significantly lower for shrimp acclimated to the 1 ppt endpoint compared to the 4 ppt endpoint. Under the reported conditions, age appears to influence PL tolerance to a salinity end‐point. A 10‐d‐old PL can be acclimated to 4 ppt with good survival, whereas 15‐ and 20‐d‐old PL can be acclimated to a salinity of 1 ppt with good survivals.

Effect of higher salinities on growth and survival of pacific white shrimp, Litopenaeus vannamei (Boone, 1931)

“…This is in agreement with the result obtained by Palafox et al (1997) and Perez -Velazquez et al (2007). Mcgraw et al (2002) reported that the longer salinities adjustment period could also result in better survival rate. Chen et al (1995) studied the survival, growth and osmolality of the haemolymph and the water content in the tissues of Fenneropenaeus chinensis juveniles, concluding that the osmolality of the haemolymph increased with an increase in salinity, and decreased with an increase in temperature.…”

“…In addition Zhu et al (2004) studied the effect of Na/K ratio on growth of L. vannamei juveniles, and stated that at higher salinities the rate of Na increased and affected the growth. This result is in agreement with the known fact that at lower salinity higher growth rate is observed (Menz and Blake, 1980;Pante, 1990;Bray et al, 1994;Somochaet et al, 1998;and McGraw et al, 2002). Menz and Blake (1980) and Bray et al (1994) reported that the L. vannamei is a euryhaline species that can tolerate a wide range of salinities (0.5-45 gL-1).…”

Effect of salinity on performance and body composition of Pacific white shrimp juveniles reared in a super-intensive system

“…In general, the survival observed in culture systems without water exchange and in association with bioflocs is high (McAbee et al, 2003;Wasielesky et al, 2006;Kuhn et al, 2008). However, the survival of marine shrimp reared at low salinities varies and may be influenced by factors such as the ionic composition of the water, the species, the age of the animals, the rate of reduction of salinity and the final salinity at which acclimation occurs (McGraw et al, 2002;Cheng et al, 2006). In this study, shrimp survival was significantly affected by salinity, with increasing mortality as the salinity decreased from 32 to 16 and 4‰.…”

“…The excellent animal-performance characteristics of L. vannamei, together with its tolerance of a wide range of salinities, have made this species attractive for culture at low salinities in several American countries (McGraw et al, 2002), Thailand (Saoud et al, 2003), Israel (Boyd, 2001) and China (Cheng et al, 2006). The production of marine shrimp in inland waters is more economically viable than marine shrimp culture in coastal zones due to the high cost of land and the strict environmental protection legislation in these coastal regions (Atwood et al, 2003).…”

Low Salinity Rearing of the Pacific White Shrimp Litopenaeus vannamei: Acclimation, Survival and Growth of Postlarvae and Juveniles

“…Previous studies have shown that it is possible to successfully grow L. vannamei in low salinity waters 20 . However, survival in the early stages of rearing is largely dependent on acclimation to low salinity conditions 15 . Postlarvae (PL) purchased from commercial hatcheries are usually shipped at high salinities.…”