Age and productivity of the Antarctic scallop, Adamussium colbecki, in Terra Nova Bay (Ross Sea, Antarctica)

Body size, geographical distribution, and biomass make Adamussium colbecki (Smith, 1902) one of the most conspicuous bivalve species in the Antarctic. Based on samples collected in austral summer 1999/2000 in Terra Nova Bay, the annual formation of shell growth bands visible on X-ray photographs was verified by stable isotope analysis. A general von Bertalanffy growth function was fitted to size-at-age data of 25 individuals (H-infinity = 108.86 mm, K= 0. 114 year(-1), t(0) = -0.367, D = 1.284). Somatic production calculated from mass-specific growth rates was 234.6 kJ m(-2) year(-1). Gonadal productivity amounted to 70.92 kJ m(-2) year(-1). Annual somatic and gonad production-to-biomass ratios (PIB) were 0.199 and 0.052, respectively. According to its consumption and production, A. colbecki is likely to play a significant role in the trophic web of Terra Nova Bay. (C) 2003 Elsevier Science B.V. All rights reserved.