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Abstract Puncture is a vital mechanism for survival in a wide range of organisms across phyla, serving biological functions such as prey capture, defense, and reproduction. Understanding how the shape of the puncture tool affects its functional performance is crucial to uncovering the mechanics underlying the diversity and evolution of puncture-based systems. However, such form-function relationships are often complicated by the dynamic nature of living systems. Puncture systems in particular operate over a wide range of speeds to penetrate biological tissues. Current studies on puncture biomechanics lack systematic characterization of the complex, rate-mediated, interaction between tool and material across this dynamic range. To fill this knowledge gap, we establish a highly controlled experimental framework for dynamic puncture to investigate the relationship between the puncture performance (characterized by the depth of puncture) and the tool sharpness (characterized by the cusp angle) across a wide range of bio-relevant puncture speeds (from quasi-static to$$\sim$$ 50 m/s). Our results show that the sensitivity of puncture performance to variations in tool sharpness reduces at higher puncture speeds. This trend is likely due to rate-based viscoelastic and inertial effects arising from how materials respond to dynamic loads. The rate-dependent form-function relationship has important biological implications: While passive/low-speed puncture organisms likely rely heavily on sharp puncture tools to successfully penetrate and maintain functionalities, higher-speed puncture systems may allow for greater variability in puncture tool shape due to the relatively geometric-insensitive puncture performance, allowing for higher adaptability during the evolutionary process to other mechanical factors.
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The biomechanics of fish skin: assessing puncture resistance to the dynamic predatory mechanism of cone snails
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.
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- Award ID(s):
- 1942906
- PAR ID:
- 10664105
- Publisher / Repository:
- The Company of Biologists
- Date Published:
- Journal Name:
- Journal of Experimental Biology
- Volume:
- 229
- Issue:
- 1
- ISSN:
- 0022-0949
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1242/jeb.250634
