Effects of seawater with different pH and alkalinity on the larval cultivation of Litopenaeus vannamei
In order to investigate the effects of different pH and alkalinity of seawater on the larval cultivation of Litopenaeus vannamei,the experiment was set up with five different gradients of pH and alkalinity to carry out the lar-val cultivation test of Litopenaeus vannamei,and to observe and compare the metamorphosis and development of lar-vae in each experimental group and the effect of nursery production.The results showed that pH and alkalinity had a significant effect on the growth and development of shrimp larvae,and that the unseasoned larval stage was more sen-sitive to changes in seawater pH and alkalinity.The larval metamorphosis and development and nursery effect were better at seawater pH 8.0-8.5,and the best nursery effect was achieved at seawater pH 8.25,with the survival rate of nursery reaching 46.25%.The alkalinity of 2.43 mmol/L to 4.252 mmol/L was the suitable concentration range for the cultivation of shrimp larvae,in which the best nursery effect was achieved with the alkalinity of 3.645 mmol/L,and the nursery survival rate reached 63.4%;when the alkalinity of the seawater increased to 4.86 mmol/L,the nursery survival rate began to decline significantly.