The effect of stocking density on growth, condition, survival and spat recruitment of the carpetshell clams Ruditapes decussata and Venerupis pullestra was studied experimentally in Lake Timsah, Suez Canal. Different sizes of clams reared in on-bottom trays at four densities (0.05, 0.1, 0.5 and 1.5 g/cm2) and its density-dependent growth and survival were monitored during spring and summer seasons. Clams showed optimum growth and conditions at densities lower than 0.1 g/cm2 in both seasons with no growth advantage at higher densities. In both species, the animal had a better growth and condition in spring compared to summer; however, survivals were approximately similar in both seasons. Spat recruitment was quite dense at higher densities particularly during the spawning season in summer. Criteria of densitydependent growth and recruitment were discussed in relation to the experin to the litions and surrounding factors.

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