アサリ漁場の餌料環境としてのセジメント

抄録

Phytopigment and organic substance in the sediment of Manila clam culture ground were investigated. Sediments were collected from the tidal flat of a Manila clam culture ground in Ariake Bay, Kumamoto Prefecture, Japan. It were detemined that contents of phytopigment (chlorophyll a and phaeo-pigments), organic substance, protein, crude fat and organic carbon in the sediment. Positive correlations were found between phytopigment and organic substances (r = 0.951), and protein (r = 0.946), and crude fat (r = 0.955) and organic carbon (r = 0.979) in the sediment. Fine particles of the sediment contained higher levels of phytopigment, protein and organic carbon. These results suggest that phytopigment quantity in the sediment may be good index for the food environment of the culture ground of Manila clam. Phytopigment contained digestive diverticula and glycogen included foot of Manila clam which were fed fine particles of sediment were also determined. Phytopigment contained digestive diverticula and glycogen of Manila clam increased with feeding fine particles of sediment. These results suggest that fine particles of sediment included phytopigment may be suitable food sources for the Manila clam.