Science: Twilight Sleep

The tough and gamy steelhead trout does not like to be artificially bred. In Oregon hatcheries, breeders get eggs from trapped females by “stripping,” or squeezing their bellies so that the eggs spurt out into a pan. Males are stripped of their milt in the same way, and when the eggs and milt are brought together, fertilization takes place quickly. But experts say that stripping a fighting, kicking steelhead is “like trying to milk a galloping cow with a greased udder.” When the fish struggle hardest, large batches of eggs and milt may be sprayed out helter-skelter and lost.

Dr. Francis Friday Griffiths, chief of scientific investigations for the Oregon State Game Commission, last week announced success of a twilight sleep technique for steelheads. The fish are taken from the traps, dunked in a solution of two parts of ether to 100 parts of water. Inert after a minute or two, they are easily stripped with practically no loss of eggs or milt. Then they are returned to their normal water, are soon as sprightly as ever. Hatchery superintendents believe that ether anesthesia will enable them to work with smaller crews next spring.