Influence of Size, Growth Rate, and Photoperiod on Cyclic Changes in Gill (Na + K)–ATPase Activity in Chinook Salmon (Oncorhynchus tshawytscha)

Publisher Website
Google Scholar
Abstract
Juvenile spring chinook salmon (O. tshawytscha) (Rogue River stock) were reared in constant 8.degree. C well water under artificial lighting with photoperiods adjusted to Medford, Oregon [USA]. Juveniles were divided into 6 groups according to the amount of food provided. Growth (change in fork length per day) was linear from July-Dec. for all 6 groups. Three distinct patterns of gill (Na + K)-ATPase activity were observed in these groups. In the 2 groups fed the largest ratios, a peak in activity in Oct. was observed with a smaller peak in July. Fish fed the smallest rations, showed no increase in gill (Na + K)-ATPase activity throughout the year. At intermediate rations, there was a small peak in July but no peak in Oct. A growth rate of less than 0.027 cm/day may suppress the Oct. peak in gill (Na + K)-ATPase activity. Fish with higher growth rates showed peaks in activity in either Oct. or Nov.

This publication has 4 references indexed in Scilit: