Fish Population Dynamic and Stock Assessment

3.1.3.3. Initial condition parameter / Arbitrary origin of growth (t₀)

It is the initial condition parameter. “t_o” is the hypothetical age, the fish would have had at zero length if they had always grown according to the VBGF equation. t₀ should be read as t zero. Usually ‘t₀’ has a negative value. t₀ is also called as ‘arbitrary origin of growth’. Biologically ‘t₀’ has no meaning because the growth begins at hatching when the larva already has certain length, which may be called L₀ when we put t = 0 at the day of birth.