The aim of study was to compare the effects of supplementation of food with herbal oils ( Thymus vulgaris and Foeniculum vulgare ) on biochemical properties and electrolytes of rainbow trout infected with Yersinia ruckeri . In total, 120 healthy fish (mean weight 84 ± 1.02 g) were equally divided into four experimental groups. The experimental study was carried out for one week. The first group was control without supplementation and infection, the second group was infected and without oil supplementation, the third group was supplemented with oils (10 ml·100 g ^-1 rates) for one week and infected with Y. ruckeri and the last group was oil supplemented without infection. Results indicated that fish fed with dietary supplements showed enhanced bactericidal activity, total protein, albumin, cholesterol, triglyceride and bilirubin compared to the control ( P < 0.05). As the value of herbal oils was increased in diets, the plasma glucose level decreased. The levels of K, Na, Ca, and Mg increased whereas Cl values decreased, compared to the control. It can be concluded that diet supplementation with herb oils used in this study can increase disease resistance by increasing levels of some biochemical parameters and electrolytes in rainbow trout to Y. ruckeri infection.

Heavy metal accumulation in freshwater ecosystem has become one of the major aquatic environmental concerns for freshwater flora and fauna due to their higher stability and bioaccumulation as well as bio-magnification properties. Furthermore, passing through the food web, these heavy metals affect human populations ultimately. This study assessed the heavy metal accumulation in Cirrhinus mrigala in spring, autumn, and winter at different locations (I, II, and III) of Panjnad headwork. Furthermore, the human health risk assessment for the consumption of C. mrigala from the sampling locations was also carried out. Fish were collected from upper (I), middle (II), and lower (III) stream of Panjnad on a monthly basis. The current study evaluated the accumulation of Aluminum (Al), Arsenic (As), Barium (Ba), and Lead (Pb) in various fish organs (liver, kidney, gills, fins, skin, muscles and bones) and assessed their potential hazard to human health through health risk assessment indicators. The results demonstrated a significant difference (p < 0.05) in heavy metal accumulation in different fish organs, seasons, and locations. The accumulation of Al, As, Ba, and Pb were considerably higher in liver and kidney as compared to the other body organs and followed a trend of liver > kidney > gills > fins > skin > bones > muscle and the overall mean concentrations of metals in different body tissues of C. mrigala were in the order of Al > As > Ba > Pb. The results also concluded that C. mrigala caught from the Panjnad headwork is not safe for human consumption due to higher values of TTHQ_Ing (3.76), THQ_Ing for Ba (3.27) and CR_Ing for As (6.4742).