Students always look forward to the hatching of their salmon/trout eggs. By tracking daily water temperatures they will be able to mathematically predict the approximate hatch date.
Eggs normally hatch over a period of days. As they do, a white foam will collect at the top of the tank. This substance results from the enzymatic breakdown of the egg shells and will dissipate after several days.
Egg care consists of removing dead eggs in a timely manner, daily if possible. If this is not done, fungus may colonize the dead eggs and jeopardize neighboring healthy eggs. Dead eggs turn white. They are removed with an "egg picker", a contraption that resembles a turkey baster. A turkey baster can be modified to act as an egg picker by cutting off its narrow tip (to accomodate the diameter of the eggs). Because eyed eggs are placed in the incubators, pre-hatch mortality should be relatively low. Below five percent can be expected.