Survival and pathology of gill tissue of juvenile Rutilus kutum from artificial propagation under stress with mud pollution and water salinity

Subject Areas : New Technologies in Aquaculture Development

smv farabi ¹ ()

Received: 2023-01-07 Accepted : 2023-01-07 Published : 2022-11-22

Keywords: Salinity, Caspian Sea, turbidity, Keywords: Rutilus kutum juveniles,

Abstract :

Abstract Pathology of the gill tissue of juvenile Rutilus kutum obtained from artificial reproduction was carried out with the aim of determining the percentage of survival when released into natural environments. Juveniles were provided from the Rajai's fish propagation center and then examined in Caspian Sea Ecology Research Center laboratory under conditions simulated with the natural environment. The juvenile fish had an allometric growth trend in the conditions of rearing in earthen ponds. The juveniles were investigated on three weight group (200<400, 400<600, 600<1000 mg) and in fresh water and Caspian Sea water (12.5 ppt). Also, six turbidity levels (50 FTU, 430FTU, 2600 FTU, 7800 FTU, 15600 FTU) were probed in freshwater during 168hr. Each treatment had three replications. The results showed that there was a significant difference among treatments in the different levels of factors, (p<0.05). The juveniles' survival rate has decreased than control treatment in brackish water and turbidity in freshwater. It was demonstrated that with increasing fish weight, therefore, the survival rate is increased. However, gill tissue of juveniles under turbidity and salinity stress became short (necrosis) and thick (edema and hyperplasia) in the end of experiments. The juveniles gill tissues were not changes in the river clear freshwater. Although the survival rate of juveniles is acceptable in this study, but there was abnormal changes in the structure of them gills. The little changes were observed in group of 600-1000 mg. It appears that these changes will cause a disruption in the trend of juvenile fish growth.