Abstract
Marine silage (MS) is a new dietary item prepared by decomposing seaweed to a cellular unit and performing lactic acid fermentation. The present paper demonstrated a large (10 L)-scale preparation and a long-term (18 months)-preservation of the MS using Undaria pinnatifida as a substrate. Furthermore, two separate feeding trials were carried out to demonstrate the dietary value of the MS to the Japanese pearl oyster Pinctada fucata martensii. In the first trial, pearl oysters grew significantly when fed the MS at 3×104 cells/mL per day. Shell growth and survival (69±11 μm/day; mean ± SE and 100%, respectively, n=30) of pearl oysters were higher than for the unfed control oysters (-26±8 μm/day and 100%, n=30), while oysters fed Chaetoceros calcitrans grew 205±12 μm/day (n=29) and 96.7% survived. Proximate analysis of the MS suggested a shortage of nutritional elements such as lipid contents. The second rearing trial demonstrated remarkable shell growth when pearl oysters were fed MS supplemented with a small quantity of C. calcitrans, although this observation is based on a single rearing result and needs repeated trials. The present study is the first to demonstrate a mass preparation of MS and its positive dietary effect for a bivalve.
