Delivery of riboflavln to larval and adult pacific oysters, Crassostrea gigas Thunberg by lipid spray beads

Lipid spray beads (SB) were prepared containing 13% w/w particulate ribofla vin. Beads suspended in seawater lost 73% riboflavin after 24 h. Release of riboflavin from SE ingested by Pacific oyster (Crassostrea gigas) larvae w as observed under epifluorescent light. Riboflavin concentrations in tissue s of adult oysters fed on riboflavin-SB were significantly (SNK, P < 0.05) greater than those of oysters fed on seawater-filled SE. Concentrations of riboflavin in oysters exposed to dissolved riboflavin were not significantl y greater than those of oysters fed on seawater-filled SE: indicating that elevated riboflavin concentrations in oysters fed on riboflavin-SB were att ributable to breakdown of ingested beads rather than uptake of dissolved ri boflavin leaked from SE into the culture medium. SE seem to be a promising means of delivering water-soluble nutrients to bivalve suspension feeders.