ONCORHYNCHUS MYKISS (WALBAUM) IN FRESH WATER AND AFTER SHORT-TERM EXPOSURE TO SEA WATER

• Main Authors: Salmon Salmo, Salar L., Rainbow Trout, N. F. Smith, F. B. Eddyt, A. D. Struthers, C. Talbot
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1991
• Subjects: Key words; renin; ANP; juvenile salmon; seawater transfer; Salmo salar; Oncorhynchus mykiss. 64 N. F. SMITH AND OTHERS It is concluded that; in fish acclimating to sea water; ANP is involved in excretion of salt loads; while the response to d; Atlantic salmon
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.326.2616; http://jeb.biologists.org/content/157/1/63.full.pdf

Freshwater Atlantic salmon (Salmo salar L.) smolts were abruptly transferred to sea water in May and over 3 days blood plasma ion concentrations were determined together with atrial natriuretic peptide (ANP) and plasma renin activity (PRA) using antibodies raised against human ANP and angiotensin I. Blood plasma Na + and Cl ~ levels in smolts increased and, between 24 and 72 h, PRA increased significantly to O.Qngml"^ " 1, while there was a gradual rise in ANP levels to lOpmoll " 1 at 72 h. Similar measurements were made on parr transferred to sea water in September; in these fish Na + and Cl ~ levels increased as in smolts, PRA remained unchanged at about 0.6ngml ~ 1 h ~ 1 and ANP levels increased significantly to about 20pmoir ' at 24 and 72 h. After 2h in sea water parr showed wide variability in ANP levels, in keeping with circulatory stress, hypoxia and increased atrial stretching. Parr transferred to sea water in December showed low drinking rates of 1.95 ml kg " 1 h " 1, even after 20 days, compared to a