Water absorption coefficients for the embryo pre and post hatch. The number represents the true absorbed mass as a proportion of the amount of yolk absorbed. Before hatching, only gas passes the egg shell, so c1 = 1. After hatching, the fish absorbs water along with nutrients. This parameter is calibrate like a1, a2, b1 and b2.
Prior to hatching, pre-hatch development rates must be calculated by the log-inverse Belehrádek model (Alderice and Velsen 1978) because hatching is a physiological stage that this model can not recognize. The proportion of pre-hatching development that occurs each day is:
These parameters are simply postpended with "hat" to be clear that they are hatching parameters. T is the temperature in Celsius on that day. Hatching occurs at time t when:
Masses of these two entities (mg) when the egg is fertilized.
Fraction of the egg that is shell material.
The julian day of the year that the fish is spawned. Note that this is significant if the temperatures vary seasonally, otherwise it will have no effect at all.
