Net calcification of the giant clam Tridacna maxima to different levels of irradiance

Metabolic and physiological responses of Red Sea Tridacna maxima clams, including net calcification and primary production, as well as valvometry (i.e. shell gaping behavior) were assessed when exposed to simulated high radiation levels received at 3 and 5 m underwater. The two levels of radiation included exposure treatments to photosynthetically active radiation (PAR; 400-700 nm) alone and to both, PAR and ultraviolet-B radiation (UV-B; 280-315 nm).