Experimental spat collection of the pearl and rocky shore oysters on ceramic tile substrates

Abstract

Temporal and spatial variation in oyster larvae settlement is a crucial factor determining the abundance and success of adult populations in their natural environment. The overall understanding of oyster recruitment provides information on site selection and strategies employed for obtaining spats for oyster culture. In this study, spat of Pinctada capensis and Saccostrea cucullata were collected from four selected sites in a sub-tropical setting at Inhaca Island, Southern Mozambique during an experimental period of 8 months to assess the effect of different factors (season, duration and surface) on spat settlement and abundance. Ceramic tiles were deployed as artificial substrates from the surface to 5 m depth. They were replaced monthly. Overall, settlement on ceramic tiles was higher for S. cucullata than for pearl oyster P. capensis. There was a tendency for higher numbers of spat settling during the summer than winter for both species. For both species larger numbers of recruits were found on tiles deployed for four months than for two months and on the roughly textured surfaces compared to smooth. The results have also indicated that the ceramic tiles could be used as substrate for rocky shore oyster S. cucullata settlement in the late summer.

Keywords

• P. capensis
• S. cucullata
• Recruitment
• Maputo bay
• Artificial collectors
• Tropical habitat