Monthly settlement of calcareous species was followed in Mar del Plata harbor (Argentina) along a year. Large number of calcareous organisms recruited onto ceramic ponéis. Balanus amphitrite and Hydroides elegans were the most representative species settled on the primary space. Other bamacles, B. glándula + B improvisus followed in importance, but the number of recruits per panel was always low. All of them were measured and total occupied oreas estimated The species showéd different settlement cycles, different preferences by both depth levels and surface texture. The máximum peak of density for B. glándula + B improvisus was in December, for B amphitrite in February and for Hydroides elegans in March. Virtually no settlement took place during colder months (June-September). Bamacles preferred to settle on the back side of the panels, with grooves and pits, while serpulids showed no texture preferences. In relation with depth all species preferred to colonize the three deepest levels. Data corresponding to growth rotes indicated a rapid development during warmer months.