PIKES AND PIKE PERCH 5 
varies greatly in different localities, extending from the last of 
March with the yellow and gray varieties to the latter part of May. 
The blue pike has not been hatched by fish-culturists, and compara- 
tively little is known of its spawning habits. 
The work of collecting eggs for artificial propagation generally 
begins about the 10th of April and extends to the 25th of that month. 
The eggs are obtained from fish taken by commercial fishermen. 
Half or more of these are hatched into vigorous fry and deposited 
in public waters, and but for this work all the eggs thus saved would 
go to the market in the abdomens of the fish and be entirely lost. 
The pike perch develops a greater number of eggs in proportion 
to its weight than the whitefish, and but a small percentage of them 
are fertilized under natural conditions. The eggs are 0.08 inch in 
diameter and average about 150,000 to a fluid quart. About 90,000 
eggs would probably be a fair average per fish for Lake Erie, and 
as the spawning fish will average about 2 pounds each, 45,000 eggs 
to the pound weight of fish would approximate the true figures. 
As the spawning time approaches spawn-takers are stationed at 
the various points on the lake where nets are to be fished. A spawn- 
taker accompanies the fisherman on his trips to the nets and examines 
the catch for ripe fish. His equipment is the same as that for white- 
fish,t except that he takes a quantity of swamp muck or cornstarch 
for use in preventing adhesion of the eggs. After he has selected 
_and stripped a fish, it is returned to the fisherman. The eggs, after 
being fertilized, are either shipped directly to the hatchery or to 
some central collecting station. 
The inner membranes of the egg are delicate and easily ruptured, 
and the greatest care is necessary, from the taking of the spawn to 
the hatching of the fry, and especially until they are cushioned by 
the filling of the membranes with water. 
The fish should be wiped so that slime will not drip into the spawn- 
ing pan, as a very small portion will clog the micropile and prevent 
impregnation. The female is grasped firmly in the left hand just 
forward of the tail, with the back of the hand downward, the fingers 
outward and the thumb above and pointing upward, the head of the 
fish being held between the spawn-taker’s right wrist and body, the 
right hand grasping the fish from below, just back of the pectoral fins, 
the fingers inward, the thumb outward. The anterior portion of the 
abdomen is thus firmly grasped and the pressure brought to bear on 
the eggs in the ovaries of the fish. A woolen mitten on the left hand 
allows a firmer grasp on the slippery body than is possible with the 
bare hand. The fish is now at an angle of 45°, the body forming a 
modified crescent, with the vent within 2 or 3 inches of the bottom of 
the pan. This position throws the pressure on the abdomen and 
facilitates the opening of the vent and the flow of the eggs. Gentle 
pressure is now maintained as long as the eggs come freely and in a 
fluid stream, probably over half of them being procured before the 
hand is moved, but when the flow slackens, and not until then, the 
hand should be moved slowly toward the vent without releasing the 
pressure and only fast enough to keep the eggs flowing in a continu- 
ous stream. When this stops the hand should be replaced and the 


‘Artificial Propagation of Whitefish, Grayling, and Lake Trout. By Glen C. Leach. 
Appendix III, Report, U. S. Commissioner of Fisheries, 1923 (1923), Bureau'of Fisheries 
Document No, 949, 32 pp., 42 figs, Washington, 
