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

## TL;DR

Fish skin resists puncture from fast-moving predators like cone snails, with its effectiveness depending on the speed and movement of the predator's attack.

## Contribution

This study reveals how fish integument dynamically resists high-speed predatory attacks, particularly from cone snails using a ballistic radular tooth.

## Key findings

- Fish integument effectively mitigates damage from predatory mechanisms at biologically relevant speeds.
- Puncture performance is significantly reduced at lower speeds in unconstrained fish targets.
- High puncture resistance is attributed to material properties, momentum transfer, and mobility of the integument.

## Abstract

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.

Summary: High-speed puncture experiments illustrate how thin fish skin can reduce damage during predation, while unconstrained fish targets require higher impact speed for full penetration.