The growth parameters for Megapitaria squalida from the eastern coast of the Gulf of California from each of the nine equations tested (only four different models) are shown in Table 2, where Gompertz and Schnute case 2 have the same parameter, as it is also special case 1 with VBGM and special case 2 with Logistic.
2 mm SL), whereas the VBGM yielded the largest one ([L.
arcuatus have directly fitted the VBGM
(Fischer & Wolff, 2006; Hernandez & Arreola-Lizarraga, 2007; Ramos-Cruz, 2008) rather than also examining alternative growth functions.
The VBGM fit to the remaining sample of 554 wreckfish used for age and growth analysis resulted in
To allow for comparison of VBGM parameters from previous age and growth studies on wreckfish, all FL measurements were converted to TL measurements and the VBGM was rerun, resulting in
Regardless of the cause, the two sources of samples included in the age and growth study produced a VBGM
with significant uncertainty, and one that may not accurately reflect the average growth rate of the species or incorporate possible variations in growth rate by location.
The underlying principle of the VBGM
is that the growth rate of individuals tends to decrease linearly with size.
Despite a lower growth rate parameter, the VBGM
predicted that OG cod will reach the same asymptotic length as cod from TL, because the asymptotic length parameter L [infinity] of approximately 120 cm did not differ significantly between the two populations (Table 8, Fig.
A common characteristic shared by these methods is to assume that species follow a VBGM
79 mm in SL), whereas the VBGM
gave the largest value ([L.
Although there are many mathematical equations used to describe individual growth parameters for populations, the VBGM
is the most popular in fisheries because its parameters are used to evaluate other fishery models, such as the yield per recruit (Kimura 1980).
and Gompertz models were supported only to a certain extent by the data, whereas [DELTA] for the Schnute model was 15.