Radial Expansion Favors the Burrowing Behavior of Urechis unicinctus

Figure 2

The large deformation of Urechis unicinctus skin. (a) The polygonal structure on the skin surface is the basis for the skin’s large deformation, and the longitudinal stress–strain relationship of the skin is similar to the circular. (b) Among the stress–strain fitting curves of the skin, the Yeoh model fits with the experimental data best. (c) Balloon expansion tests under the sands are used to indirectly measure the pressure required for the radial expansion of Urechis unicinctus.

(a)

(b)

(c)