Fig. 5: Backward clamping with ventral bulb and its muscular substrate in Asian elephants (E. maximus).
From: Elephant trunk tip musculature reflects species differences in grasping behavior
a E. maximus clamps corn cob between trunk and ventral bulb. Credit: Lena Kaufmann. b Close-up of E. maximus trunk tip. The corn cob is clamped between the ventral side of the trunk and the ventral bulb of the trunk tip. c Lateral view of volume rendering of E. maximus trunk tip. Arrow indicates grove of ventral bulb. d Ventral view of volume rendering of E. maximus trunk tip. e Lateral cross-section of E. maximus trunk tip. Longitudinal muscle fascicles on dorsal side (blue), converging longitudinal muscle fascicles (green), and radial muscle fascicles (red). Schematic shows where the respective cross-section was taken. Arrow indicates grove of ventral bulb. f Left, schematic of lateral cross-section of E. maximus trunk tip in relaxed state. Right, retracted state. When converging longitudinal (green) and radial (red) muscle fascicles in the ventral bulb contract, the ventral bulb elongates and retracts to the proximal direction of the trunk. g Lateral cross-section of L. africana trunk tip. Longitudinal muscle fascicles (blue) run parallel to the long-axis of the trunk tip. Radial muscle fascicles (red) intersect the longitudinal muscle fascicles. h Left, schematic of lateral cross-section of L. africana trunk tip in relaxed state. Right, Pinched state. When longitudinal (blue) and radial (red) muscle fascicles (red) in the ventral bulb contract, the ventral bulb elongates and retracts to the proximal direction of the trunk. V, ventral; dis, distal; lat, lateral. Scale bars (c, d, e, g), 10 mm.
