Fig. 12. Material properties of the bulbi of yellowfin and bigeye tuna. (A) Stress-strain curves. (B) Modulus-strain curves. The following rectangular tissue samples were stretched using a micromanipulator: YF, yellowfin tuna; BE, bigeye tuna; ML, segment of the middle layer; ILE, segment of longitudinal element; OL, segment of the outer layer; circ., stretched circumferentially; long., stretched longitudinally. The asterisk represents a tissue sample that was stretched as a loop using the custom-built stretching machine.