Age and growth of the queen scallop, Equichlamys bifrons, in the D'Entrecasteaux Channel and Huon River Estuary, Tasmania

Abstract

Growth of the queen scallop, Equichlamys bifrons, was examined at one site in the D'Entrecasteaux Channel and two sites in the Huon River estuary (Tasmania) by analysing growth rings on the shell and shell hinge ligament, tagging scallops, and using size-frequency techniques. Regular sampling of scallops revealed that shell growth of E. bifrons is seasonal, commencing in late spring and stopping in late autumn. During the remainder of the year, when the water temperature is below ~13ºC, shell growth slows or stops and growth rings are formed on the shell and shell hinge ligament. The growth rings on the shell and hinge ligament of E. bifrons were verified as being annual by studying the growth of marked scallops. Long-term growth patterns were similar for E. bifrons from Middleton (D'Entrecasteaux Channel) and from Deep Bay (Huon River estuary). Tagging data collected over the 1992-93 growing season indicated short-term variation in growth between sites. Size-frequency distributions from Middleton and Deep Bay could not be interpreted because smaller scallops were scarce. Smaller size classes were present at Eggs and Bacon Bay (Huon River estuary) and the size-frequency distribution was resolved into age classes. Reasonable agreement was found between the von Bertalanffy growth parameters obtained from the size frequency, tagging, and growth ring data.