Estimation of growth parameters of male blue crabs Callinectes arcuatus (Brachyura: Portunidae) from the Gulf of California using the Schnute model

This study describes the growth parameters of males of the blue crab Callinectes arcuatus based on samples from a coastal lagoon in the southern Gulf of California and from individuals raised under controlled conditions. The models assessed were the four variants of the Schnute growth model and a special case of the von Bertalanffy model (VBGM). The Akaike information criterion was used to select the best model. The models with the best fit were Case 3 of the Schnute model for the separated wild and captive-reared data sets, but the combined data set fit better to the VBGM function, indicating linear growth, and Case 5 suggesting asymptotic growth of the C. arcuatus. Our results depend on the assumption that reared and fished individuals were covering the entire benthic growth period. It is concluded that 1) modeling growth by treating cohorts as individuals yields accurate estimations of k and the [L.sub.[infinity]] equivalent that can be used directly in stock assessment models, and (2) the ranges of validity of the best growth models for C. arcuatus growing in wild and cultured environments overlapped in the size range of 62 to 85 mm of carapace/width, but they have a continuity that represents blue crab growth throughout their benthic life.