抄録
Aprotein fraction extracted from squid (squid protein fraction=SPF) was tested in Penaeus japonicus juveniles. SPF was substitued for purified fish protein in a mixed diet at a level ranging from 1.5 to 16% all diets being isolipidic and isoproteic. No change in food intake was observed, but weight gain and number of molts increased with SPF level and reached a plateau over 6% SPF. Food conversion was also improved by the addition of SPF. DNA content of whole shrimp did not change, but RNA and RNA to DNA ratio varied in a manner similar to weight gain suggesting that growth enhancement was due to hypertrophy of cells, not to hyperplasy. No clear effect of SPF on amylase or total proteases activities was found.
