Preliminary studies on the absorption rates and the feeding effects of different diets on sea-slug Onchidium sp.

Abstract

Six types of diets (corn flour, repseed meal-solvent, soybean meal-solvent, wheat middling, yeast and fish meal ) were tested to compare their feeding effects on the survival rate and growth of sea-slug Onchidium sp. in this study. The absorption rates of 3 diets were also determined using the hydrated Cr2O3 cineration quantitative method. The objective of this study was to find a most suitable diets for the future aquaculture of sea-slug. The results showed that the feeding effect of animal diets was poor, which would cause the deterioration of water quality readily. It was proved that the sea-slug preferred to herbivorous diets, with a preference order to the six feeds as corn flourrepseed meal-solventsoybean meal-solventwheat middlingyeastfish meal. The mean absorption rates of the sea slug on the 3 diets of corn flour, repseed meal-solvent and wheat middling were 21.680%, (14.262)% and 4.871% respectively. It was also found that the corn flour yielded the best feeding effects, which enabled the sea-slug to complete its reproductive behavior such as mating, egg laying and re-mating, re-egg-laying etc. under laboratory condition, with a daily ration of 1% to 5% of their body weight.