The Activity of the Spermatozoa of Salmo Salar in Relation to Osmotic Pressure

Abstract

1. The spermatozoa of the salmon, whether from parr or from fully grown males, remain active in various dilutions of sea water for a much longer time than in river water. The duration of activity is greatest in about 20% sea water. 2. Sucrose solutions also prolong the activity of salmon spermatozoa, the maximum duration of activity in sucrose being in a solution of the same osmotic pressure as 25% sea water. Hence the activating effect of sea water must be osmotic rather than ionic. 3. In the egg fluid of the salmon the spermatozoa retain their activity for much longer periods than in 20% sea water or in sucrose. Even after activity has stopped in egg fluid, the sperm may remain potentially active, in the sense that their activity may be restored by transference to sea water or to sucrosé.