R.R. Rucker 1949 <p>I was glad to see "Fact and Fiction in Spawntaking" by Wood and Dunn (1948) in a recent issue of the PROGRESSIVE FISH CULTURIST. Having spent two seasons at the Yellowstone Park station, I also attempted to find ways of increasing the efficiency of fertilization and several years ago conducted a few experiments along these lines. From these experiments I obtained some "facts and fiction" that I believe are particularly germane and will be of interest to anyone who spawns fish.</p> <p>I often dreamed of some Utopian technique for spawning fish--a technique that would insure 100-percent fertilization. My approach to this was an attempt to find a solution that would keep the sperm viable and active for a period of minutes rather than seconds and one that would allow eggs to remain receptive to the sperm for the same period.</p> <p>The work of Ellis and Jones (1939) indicated that a solution of comon salt would prolong the life of fish sperm, although the work of Schlenk and Kahmann (1938) indicated that a more complex solution must be used. I therefore tested on sperm many solutions which waried in composition, strength, pH, and temperature. None of these prolonged viability to the point where 100-percent fertillzation could be expected after a few minutes" exposure at best. There was no difficulty in prolonging the fertilizable life of the egg: a plain salt solution was found quite effective, as mentioned by Rutter (1904).</p> application/pdf 10.1577/1548-8640(1949)11[75:FAFIS]2.0.CO;2 en Bureau of Fisheries, U.S. Deptartment of Commerce Fact and fiction in spawntaking: Addenda article