Body size, geographical distribution and biomass make Adamussium colbecki (Smith 1902) one of the most important 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 analyzis. A general von Bertalanffy growth function was fitted to size-at-age data of 25 individuals (H*= 108.86 mm, K= 0.114 y-1, t0= -0.367, D= 1.284). Maximum age of A. colbecki is likely to be more than 18 years. Somatic production calculated from mass-specific growth rates was 235 kJ m-2 y-1. Gonadal productivity estimated by an average value for reproductive output of pectinids amounted to 59 kJ m-2 y-1. Annual somatic and gonad production-to-biomass ratios (P/B) were 0.199 and 0.043, respectively. According to its consumption and production A. colbecki is likely to play a significant role in the trophic web of Terra Nova Bay.