A mass mortality of two-year-old American razor clams E. directus in the Wadden Sea near Texel in February 2003 enabled us to compare shell growth in the first and the second year. In general the shells that had reached larger length in the first year were also larger after the second year. However, the smaller ones at the end of the first year showed a ‘catching-up phenomenon’: they had grown relatively faster in their second year, but not enough to reach the same size as the larger ones of the first year.