Based on the exploratory analyses (see Section 4), a two-stanza growth model was deemed most appropriate for all three species.We chose to fit the VB log k growth function (von Bertalanffy witha logistic growth rate parameter) developed by Laslett et al. (2002).This function allows for a smooth transition between grow thphases, which seems more likely from a biological point of viewthan the instantaneous transition assumed by the two-phase VBgrowth model of Hearn and Polacheck (2003).The VB log k growth function can be expressed as