Grow-out studies of the scallop Pecten sulcicostatus, endemic to the South African coast, contribute to an investigation of the suitability of this species for commercial culture.Three hundred laboratory-reared juveniles were placed in a suspended culture system at 5 m depth in Saldanha Bay on the west coast of South Africa.The 78-day-old scallops which ranged in size from 4.5-11.0 mm shell height (mean of 6.9 mm), as measured on 2 February 2010, were deployed in Saldanha Bay on 9 February 2010.Subsequent growth was assessed monthly and is presented through changes in shell height.These growth data are examined in relation to changing environmental conditions as determined through continuous measures of temperature and fluorescence.On 16 November 2010 animals ranged in size from 30.6-58.3 mm (mean of 48.2 mm), representing an increment in shell height of 41.3 mm over a period of 287 days.The mean growth rate of 0.14 mm day-1 compares favourably with other commercially cultured species and exceeds previous estimates of growth of naturally occurring populations of P.sulcicostatus.Monthly estimates of growth varied between 0.06 and 0.21 mm day-1 and are assessed in relation to seasonal changes in the physical environment and to changes in food availability.Projections based on these data indicate that P.sulcicostatus will reach market size (70-90 mm) within 16-20 months.