Estimating growth of the Florida spiny lobster, Panulirus argus, from molt frequency and size increment data derived from tag and recapture experiments

Molting schedules and growth per molt of Panulirus argus were deduced by gender from size at tag and recapture of 3481 females and 3330 males released off the Florida coast during 1967–2003. Functional relationships were estimated for the intermolt period from premolt carapace length (CL) and for growth increment from premolt and postmolt CL. Starting at 5 mm CL stepwise growth functions were derived by repeatedly applying these two functions in succession. Growth curves were simulated for each sex to 30 years maximum age. At maximum age females reach a CL of 151 mm and males reach 220 mm. Significant slowdown of growth is expressed by an abrupt change in the intermolt period at the onset of maturity, while there is no evidence of a change in slope of the postmolt and premolt functions at that time. The segmented growth characterizations differ very significantly from all of the von Bertalanffy-type functions estimated for the species from indirect ageing procedures.