Publikationsdatum:
2021-05-19
Beschreibung:
The survey effect of salinity, turbidity and dissolved oxygen performed on Rutilus frisii Kutum juveniles with aim, which was determined about survival rate and histological changes in gill and kidney tissues. Juveniles provided from the Rajai's fish propagation center and then examined in Caspian Sea Ecology Research Center laboratory. The juveniles were investigated on three weight group (200-〈400, 400-〈600, 600-〈1000 mg) and two dissolved oxygen levels (7.6 ± 0.19, 3.8 ± 0.15 mg/L)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 has three replications. The factorial test evaluated for survival rate in treatments. The results shown that there was a significant difference among treatments in the different levels of factors, (p〈0.05, Duncan test). 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. The lowest survival rates under salinity stress (〉75%) had shown in 400-〈600mg weight group with dissolve oxygen:
3.8±0.15SE mg/l. In addition, the lowest survival rates under turbidity stress (95.83%) had shown that in weight group less than 400 mg with turbidity 15600 FTU. Therefore, survival of juveniles was high. 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. Therefore, the factors of gill tissue deformation were salinity and suspended particles in the water. However, the structures of kidney in the different groups of juveniles were similar. Nevertheless, juveniles glomerular diameter increased with increasing weight (p〈0.05, Duncan test). Furthermore, there was a increasing the internal cavity of the proximal and distal tubules and decreasing of glomeruli in diameter in the transfer of juveniles from freshwater to brackish water. Although the survival rate of juveniles is acceptable in this study, but there was abnormal changes in the structure of them gills. It appears that this change will cause a disruption in trend of juvenile's growth.
Beschreibung:
Iranian Fisheries Science Research Institute
Beschreibung:
Published
Schlagwort(e):
Ecology
;
Rutilus frisii Kutum
;
Juvenile
;
Salinity
;
Turbidity
;
Oxygen
;
Survey
;
Survival rate
;
Gill tissue
;
Freshwater
;
Brackishwater
Repository-Name:
AquaDocs
Materialart:
Report
,
Refereed
Format:
71pp.
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