Changes in electrolytes levels in the plasma of Clarias gariepinus juveniles and adults reared in two grow-out facilities
Variations of some electrolytes such as Sodium (Na+), Potassium (K+), Chloride (Cl-) and Calcium (Ca2+)in the plasma of Clarias gariepinus juveniles and adults reared in grow-out concrete tanks and earthen ponds in three Agricultural Zones of Lagos State were assessed to determine the levels of osmotic impairment in fish raised using two grow-out aquaculture facilities. A total of six farms and a control farm were selected for the study based on their culture systems and production capacities (earthen ponds and concrete tanks). Sixty-four blood samples were collected from juveniles and adults of catfish reared in these farms for six months. Blood samples were analyzed by standard laboratory methods using Randox diagnostic test kit. Results from the electrolytes analyses indicated that the values of Na+ and K+ ions significantly increased (P < 0.05) in all the farms when compared to the control values. However, there was no significant difference (P > 0.05) in Cl- between the control and other farms. While significant reduction (P < 0.05) of Ca2+ were recorded in other farms when compared to the control. These alterations were more noticeable in the fish reared in MOY and TEM fish farms than other farms.
Keywords: Aquaculture, stress, electrolytes, culture systems, catfish