where ρ is the bulk density, M is mass of the rice, and V is the volume of the bucket. To determine the fish volume, a half kilogram of rice was first poured into the empty bucket. The frozen fish was then placed into the bucket with the tail facing up to prevent rice from entering the mouth cavity. A half kilogram of rice was added at the time until the bucket was filled. Every time a half kilogram of the rice was added, the bucket was tapped 10 times. The bucket was then weighed, and the fish volume was calculated as