Fish health and Disease Department. International Sturgeon Research Institute.
Abstract
Oxygen, like temperature, is an important factor in the metabolic rate of fish. Insufficient oxygen lowers and disrupts the metabolic rate, resulting in death from suffocation. Hypoxia is a phenomenon that occurs in aqueous environments and is generally called a hypoxic water system with a low oxygen concentration between 1 and 30% saturation. Hypoxia can be harmful or deadly to fish, even for a short time. Hypoxia (2-3 mg/l) in farmed beluga with an average weight of 280.9±49.2 g and 1217.9±138.1 g, in a period of two months caused tissue damage in the gills and spleen and changes in physiological indices and the fish did not have normal general conditions, swam more slowly and showed no desire to intake food. The decrease in feed intake in beluga is due to the fish's efforts to make optimal use of oxygen, which also leads to reduced growth, and this ultimately causes the general weakness of the fish and makes the fish susceptible to disease. Although beluga can survive with a minimum of 2-3 mg/l of oxygen, not only they do not grow but they also lose weight, which will lead to aquatic economic loss due to the long beluga culture period. Therefore, due to the fact that hypoxia has an adverse effect on the health of beluga, it is recommended to breed these fish with high oxygen (9-10 mg / l).
