Shape of Silkworm cocoon changes with size in some races

Abstract

In general, the basic shape of Silkworm (Bombyx mori) cocoons is thought to depend upon race and not the size of the cocoon. That is, it is thought that within species, changes in the size of cocoons are proportional. The ratio of cocoon length to width is commonly used to numerically express the shape of cocoons. In the present study, we employed a Fourier coefficient in order to express the cocoon shape in detail. We found that in some Chinese silkworm races, the basic shape of the cocoon changed with size. The shapes of the geographical silkworm races have been precisely reported by Enokijima et al. (1985) through the ratio of the length to the width of the cocoon.