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3.1.3.5. Growth rate
3.1.3.5. Growth rate
The growth rate is denoted by
$${\triangle L \over \triangle t}={L (t+\triangle t) - L(t) \over \triangle t}$$ ………………… (1)
Time (or age), t is usually expressed in units of years.
The mathematical relationship between the length of a fish and the growth rate at a given time is a linear function.
$${\triangle L \over \triangle t}= a + b ^\ast L(t)$$ …………………(2)
Using VBGF equation, linear relationship can be derived as follows :
$${\triangle L \over \triangle t}= K ^\ast (L_\infty - L(t)) \ cm/year$$ ………………… (3)
where K = - b and $$L_{\infty} = -a/b$$
The mean growth rate (in length) can be calculated using the equation
$${ \overline L_t}={L(t+ \triangle t) + L(t) \over 2 }$$ …………………………… (4)
Last modified: Friday, 22 June 2012, 5:49 AM