Cortisol stimulates hypo-osmoregulatory ability in Atlantic salmon, Salmo salar L.
Article first published online: 24 JAN 2006
Journal of Fish Biology
Volume 39, Issue 3, pages 421–432, September 1991
How to Cite
Bisbal, G. A. and Specker, J. L. (1991), Cortisol stimulates hypo-osmoregulatory ability in Atlantic salmon, Salmo salar L. Journal of Fish Biology, 39: 421–432. doi: 10.1111/j.1095-8649.1991.tb04373.x
- Issue published online: 24 JAN 2006
- Article first published online: 24 JAN 2006
- Received 24 September 1990, Accepted 1 April 1991
- salinity tolerance;
- Atlantic salmon
Hypo-osmoregulatory ability in juvenile Atlantic salmon, Sulrno salur L., was improved by cortisol treatment. Implantation of a vegetable shortening pellet containing cortisol (50 mg kg−1) resulted in elevated plasma cortisol titres. Maximum cortisol levels (160–170ngml−1) were observed at days 6 and 12 after the implantation and dropped significantly by day 55. Cortisol-implanted fish in fresh water developed a twofold increase in gill Na+/K+-ATPase activity at days 6 and 12, and a threefold increase by day 55. Intestinal mucosa Na+/K+-ATPase activity was not affected by cortisol. Cortisol-implanted fish exposed to 28 ppt sea water for 48 h tended to show an improved ability to regulate their plasma osmolarity and reduce their ionic load. The osmo-regulatory ability attained at days 12 and 55 was further evaluated by exposing fish to 37 ppt sea water for 96 h. While all the control fish died relatively early in these tests, cortisol-implanted fish showed a clear reduction in their mortality rate. These results indicate that cortisol can induce biochemical and organismal changes during winter months that typify preadaptive events normally occurring in the spring.