The biomechanics of fish skin: assessing puncture resistance to the dynamic predatory mechanism of cone snails.

In aquatic species such as fish, the integumentary system, comprising skin and scales, serves as a crucial defense against puncture from high-velocity impacts. While previous studies have focused on quasistatic puncture behavior and constrained targets, here we investigated the less-studied dynamic puncture behavior in both constrained and unconstrained fish integument samples. We used cone snails as a model organism, which utilize a ballistic radular tooth to penetrate and paralyze prey. Our dynamic puncture experiments demonstrate that fish integument effectively mitigates damage from predatory mechanisms at biologically relevant speeds. While higher velocities typically result in deeper penetration, puncture performance is significantly reduced at lower speeds in unconstrained targets. These findings reveal the protective function and biomechanical efficiency of fish integument, with high puncture resistance attributed to material properties, momentum transfer and mobility. Our results highlight the adaptive strategies of cone snails in overcoming these defenses with greater velocity and energy.