Salinity tolerance establishment of Rutilus frisii kutum fingerlings using hydrocortisone sodium phosphate bathing treatment and its effect on the size and number of gill chloride cell

Paper ID : 1092-ICIAQUA

Authors

Nazir Vahedi *1, Bagher Mojazi Amiri2, Mohammad Ali Nematolahi2, Hadi Poorbagher2 1First author 2Co-author

Abstract

Nazir Vahedi1, Bagher Mojazi Amiri2, Mohammad Ali Nematolahi2, Hadi Poorbagher2 1 Fisheries Administration of Kurdistan, Department of Aquaculture, Sanandaj, 66169-35383, Iran 2Department of Fisheries and Environmental Sciences, Faculty of Natural Resources, University of Tehran, 31585-4314, Karaj, Iran [email protected] Purpose: This study was conducted in order to reduce the salinity stress influences and increasing salinity tolerance establishment in Rutilus frisii kutum fingerlings and prepared them for releasing in the estuaries. Method: Fingerlings samples were taken from the Shahid Rajai propagation center and carried out to the faculty of Natural Resources of Tehran University. Hydrocortisone sodium phosphate bathing treatments were consisting of three levels of hormone (3, 5 and 7 ppm) and for different periods of incubation (24, 48, or 72 h). At the end of bathing, number and size of gill chloride cells were measured.Then to assess the osmoregulation mechanism of fingerlings after hydrocortisone sodium phosphate bathing treatments, the fingerlings exposed to salinity (7 ppt) for 72 h and then above parameters were measured by sampling at 0, 6, 12, 24, 48 and 72 h after treatments. Results: Results shown that these parameters increased with an increase in hormone concentration and periods of incubation (p <0.05). But, when longer duration was accompanied with higher concentration, treatment with hormone led to increase of mortality. Results shown that number and size of chloride cells were increased in the first hours of treatment and then remained without significant change. Mortality was recorded in 3 ppm with 24 h incubation, 7 ppm with 48 h incubation, 5 and 7 ppm with 72 h incubation and control treatments (p <0.05). Conclusions: According to the present results bathing fingerlings by 5 and 7 ppm along with 24 h incubation can reduce the stress caused by salinity and play a role in preparing of them for releasing in the estuaries.

Keywords

Rutilus frisii kutum, salinity stress, hormonal treatment, gill chloride cell

Status: Abstract Accepted (Oral Presentation)