Research Publications: UM-SG-RS-2006-06

Title:

Temperature-dependent growth of the blue crab (Callinectes sapidus): a molt process approach.

Year:

2006

Authors:

Brylawski, BJ; Miller, TJ

DOI:

10.1139/F06-011

Abstract:

Crustaceans display discrete and biphasic growth as a result of the molting process, so the traditionally used von Bertalanffy growth model does not capture well the phenomena associated with molting-based growth. A molt-process model can predict crustacean growth, including the temperature dependence of intermolt period that can produce the extended overwintering phenomena during which growth ceases. This study parameterized a molt-process model for the blue crab (Callinectes sapidus; Portunidae). Crab growth histories were observed for individual crabs held in field enclosures and temperature-controlled, recirculating tanks. A growth-based temperature of torpor (T-min) of 10.8 degrees C was determined. A mean growth per molt of 119.5% increase in carapace width was observed. The average intermolt period observed was 536 +/- 231 degree-days. The predictive ability of these growth parameter estimates was evaluated against growth observed in the field based on data on interannual changes in size frequencies of crabs from a winter dredge survey. The evaluated model was used to explore recruitment timing in warm (1996) and cold (1998) years. A 10% shift in the timing of juvenile crabs becoming available for legal exploitation was predicted from the simulations.

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