Advances in Tropical Biodiversity and Environmental Sciences 6(3): 85-89, October, 2022 e-ISSN:2622-0628 DOI: 10.24843/ATBES.2022.v06.i03.p04 Available online at: https://ojs.unud.ac.id/index.php/ATBES/article/view/92350 85 The Effect of Reduce Salinity on Behavior and Stress Response in Vannamei Shrimp (Litopenaeus vannamei) Edita Rum*, Yudiana Jasmanindar, and Ade Yulita Hesti Lukas Aquaculture Study Program, Faculty of Marine Animal Husbandry and Fisheries, University of Nusa Cendana *Corresponding author: editarum18@gmail.com Abstract. One of the parameters that plays an important role in the success of vannamei shrimp cultivation is salinity. This study aims to determine the effect of decreasing salinity on the behavior and stress response of vannamei shrimp. The test animals used were vannamei shrimp, which were in logs with an average weight of 4.6-6.3g. This study used a completely randomized design (CRD) with different salinity reduction treatments in each maintenance medium, namely Treatment A without decreasing salinity, Treatment B decreasing salinity 2 ppt per 6 hours for 24 hours, Treatment C decreasing salinity 2 ppt per 4 hours for 24 hours, Treatment D decreased salinity 2 ppt per 2 hours for 24 hours, each treatment was repeated 3 times. Blood glucose was measured after the decrease in salinity and the last day of the study. Blood glucose collection was carried out at the fifth swimming leg on white shrimp using a 1 ml syringe that had been rinsed using Na Citrate with the aim that the blood glucose taken did not clot quickly. The results showed a decrease in salinity caused shrimp stress. The concentration of vannamei shrimp blood glucose increased (13.66 – 52.37mg/dl). Treatment D was the best glucose concentration to suppress blood glucose concentrations (13.66mg/dl). Based on the data analysis of blood glucose concentration (p<0.05) so that it was continued with the real difference test. Vannamei shrimp behavior during salinity reduction showed a response that was not different from all treatments. Salinity 6 ppt is good salinity in the process of suppressing blood glucose concentrations when changes in water salinity occur. Keywords. Blood glucose, behavior, Litopenaeus vannamei, salinity; I. INTRODUCTION Vannamei shrimp (Litopenaeus vannamei) is a marine fishery commodity that has high economic value in both domestic and global markets [5]. Vannamei shrimp has a fairly high tolerance to fluctuations in salinity and temperature [7]. Vannamei shrimp cultivation in Indonesia has not been widely carried out in areas far from seawater sources [6]. Success in vannamei shrimp enlargement is one of the most important steps in the aquaculture chain system, which is to support the business of providing quality shrimp. The parameter that is very important in supporting the growth and survival of vannamei shrimp is salinity [2]. Vannamei shrimp that are 1-2 months old require a salt content of 15-25 ppt for optimal growth [13]. The advantages of this vannamei shrimp are high selling price, easy to cultivate and resistant to disease. Environmental conditions can affect the growth and stress response of vannamei shrimp. Changes in salinity in water can cause osmotic pressure that is different from the osmotic pressure in the body of aquatic organisms so that organisms must carry out an osmoregulation mechanism [12]. The inability of the shrimp to control the osmotic balance in their body can cause the shrimp to be stressed. In addition, changes in salinity can affect the homeostasis of vannamei shrimp which in turn has an impact on growth and survival. Changes in environmental conditions will also result in changes in the allocation of energy in the fish body [12]. Stress is a non-specific response in the body to the many needs due to exposure to stressors. Stress is usually considered as an effort to maintain environmental stability [10]. [4] To deal with environmental conditions that can affect physiological conditions and can cause stress, crustaceans can utilize energy from the glycolysis process which is regulated by crustacean hyperglycemic hormone (CHH) which functions to increase blood glucose levels in shrimp. Glucose levels are regulated in