Fig. 6. (A) Stress–strain hysteresis loops obtained from three successive deformation cycles before application of H-tensilin in Ca²⁺-free artificial seawater (Ca²⁺-free ASW). The shape of the loops did not vary much from cycle to cycle. One of the loops (circles) is also shown, as a control, in B. The stress was normalized by the maximum stress in each hysteresis curve. (B) Typical hysteresis loops before (circles) and after (triangles) application of H-tensilin (3 µg ml^–1) in Ca²⁺-free ASW. Empty symbols represent loading curves; filled symbols represent unloading curves. H-tensilin reduced the difference between loading and unloading curves.