The influence of cactus spine surface structure on puncture performance and anchoring ability is tuned for ecology

Abstract

ResearchCite this article: Crofts SB, Anderson PSL. 2018 The influence of cactus spine surface structure on puncture performance and anchoring ability is tuned for ecology. Proc. R. Soc. B 285: 20182280. http://dx.Spines are common morphological features found in almost all major biological groups offering an opportunity to explore large-scale evolutionary convergence across disparate clades. As an example, opuntioid cacti have spines with barbed ornamentation that is remarkably similar in form and scale to that found on porcupine quills, suggesting specific biomechanical convergence across the animal and plant kingdoms. While the mechanics of porcupine quills as defensive mechanisms has been previously tested, the mechanics of cactus spines (which have evolved to fill a number of functions including defence, climbing and dispersal) has not been characterized.Here we study the puncturing and anchoring ability of six species of cactus, including both barbed and non-barbed spines. We found that barbed spines require less work to puncture a variety of targets than non-barbed spines. Barbed spines also require more work than non-barbed spines to withdraw from biological materials, owing to their barbs engaging with tissue fibres. These results closely match those found previously for barbed versus non-barbed porcupine quills, implying biomechanical convergence. The variation in performance of barbed versus non-barbed spines, as well as between barbed spines from different species, is probably tied to the diversity of ecological functions of cactus spines.

How do morphological sharpness measures relate to puncture performance in viperid snake fangs?

“…Vipers tend to have stouter bodies than other snakes [31], which may result in more force during strikes, allowing for greater fang included angles, such as those we found in the B. gabonica fangs. Future work on biological puncturing tools should help to determine if the same patterns hold true, detect variations in morphology that may account for the disconnect between the engineered tools and fangs and may lead to improved bioinspired needle designs [39,40].…”

Resource allocation to a structural biomaterial: Induced production of byssal threads decreases growth of a marine mussel

“…The specialized mechanical structures that organisms produce, such as cactus spines, spider webs and bivalve shells provide a range of fitness advantages, including predator deterrence, resource acquisition and abiotic stress amelioration (Crofts & Anderson, 2018; Gosline, 2018; Vogel, 2013). The production of a structural biomaterial, however, requires an investment of energetic resources.…”

Predator–Prey Interactions Examined Using Lionfish Spine Puncture Performance

“…We hypothesize that all lionfish spines are considered to be relatively sharp puncture tools because they all were able to puncture porcine skin. Similarly, only cactus spines that were classified as being sharp were able to puncture porcine tissue (Crofts and Anderson 2018 ). In our data, lionfish spines often fractured at the tip post puncture which embedded spine fragments into rougher materials such as shark buccal skin.…”

“…2016 ). Puncture performance not only depends on the sharpness, shape, and material properties of the tool, but also the target material, the speed of puncture, and the properties of the fluid medium ( Anderson 2018 ; Crofts and Anderson 2018 ; Crofts et al. 2019 ).…”