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Skin reflectance as a non-lethal measure of smoltification for juvenile salmonids

January 1, 1995

Our efforts to find nonlethal methods of assessing the parr-smoll transformation of juvenile steelhead Oncorhynchus mykiss and spring and fall chinook salmon O. tshawytscha led to the development of a video system for quantitatively measuring skin silvering using skin reflectance. Gill Na'.K'-ATPase activity, skin guanine concentration, and skin reflectance were recorded from groups of fish marked with freeze brands at hatcheries and downstream sample sites in the Columbia River basin. Skin reflectance of migrants was significantly higher than that of fish before release; nonmigrants (released fish that did not migrate) had significantly lower skin reflectance than migrants from the same groups. Skin reflectance was significantly correlated with gill ATPasc activity and skin guanine concentration. Skin reflectance increased during the parrsmolt transformation and could be used as a nonlethal indicator of smoltification.

Publication Year 1995
Title Skin reflectance as a non-lethal measure of smoltification for juvenile salmonids
DOI 10.1577/1548-8675(1995)015<0814:SRAANM>2.3.CO;2
Authors Philip V. Haner, Joyce C. Faler, Robin M. Schrock, Dennis W. Rondorf, Alec G. Maule
Publication Type Article
Publication Subtype Journal Article
Series Title North American Journal of Fisheries Management
Index ID 70180320
Record Source USGS Publications Warehouse
USGS Organization Western Fisheries Research Center
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