Multiscale Biological Composites: The Stomatopod Telson: Convergent Evolution in the Development of a Biological Shield (Adv. Funct. Mater. 34/2019)

Abstract

In article number 1902238, David Kisailus and co‐workers identify multiscale structure‐mechanical property relationships within the shield‐like exoskeletal telson structure of the mantis shrimp, used for defense and protection. Comparison of telsons from two evolutionarily divergent species reveal differences in macromorphology, cuticle thickness, and mineralization, imparting compressive stiffness as well as compliance for energy absorption (Photo by Roy Caldwell; rendering by Jesus Rivera).

Design Strategies of the Mantis Shrimp Spike: How the Crustacean Cuticle Became a Remarkable Biological Harpoon?

“…This dual mineralization is a specific reinforcement feature of raptorial appendages used for impaling or smashing preys as well as for fighting with opponents [28,32,[34][35][36] . In general, the electron dense region is particularly pronounced on the impact surface and much less in other region of the cuticle [9,42] . After a heavily mineralized and sharp tip, characterized by a radius of curvature of about 20 μm, which should facilitate puncture into the tough skin of the preys, the spike exhibits a spatially varying geometry.…”

“…Food treatment (e.g. through mandibles and stomach teeth) [7] , mechanical [8,9] and optical shielding [10] , as well as puncturing and capturing [11] are additional ingenious functions performed with the cuticle. It is remarkable that such multifunctionalitiy is obtained thanks to a tiny and lightweight biological structure, formed by the epidermis, renewed periodically by the moult process, and essentially comprising a thin superficial waterproof layer (the epicuticle) made of a lipid-protein matrix, and a thicker internal fibrous layer (the procuticle), generally subdivided into exo-and endocuticle depending on secretion time [12,13] .…”

“…An instructive example of how the cuticle has evolved into highly specialized tools, even within the same organism, is found in the stomatopod crustaceans (or mantis shrimps). During their evolution, these marine animals modified their cuticle for feeding, hunting and defense purposes [9] . Stomatopods are traditionally subdivided into two branches based on the structure of their anterior appendages [26][27][28] : the well-known "smashers", that use a hammer-like club to destroy hard-shell preys, and the less-famous "spearers" (Figure 1 A) that have a harpoon-like appendage to impale and grasp their (generally) soft-body preys.…”

Design strategies of the mantis shrimp spike: How the crustacean cuticle became a remarkable biological harpoon

“…28,32,[34][35][36] In general, the electron-dense region is particularly pronounced on the impact surface and much less in other parts of the cuticle. 9,42 After a heavily mineralized and sharp tip, characterized by a radius of curvature of about 20 μm, which should facilitate puncture into the tough skin of the preys, the spike exhibits a spatially varying geometry. The cross sections have an ellipsoidal profile, and the cross-sectional area increases gradually from the tip to the base, always having a pronounced eccentricity (Figure S2).…”

“…During their evolution, these marine animals modified their cuticle for feeding, hunting, and defense purposes. 9 Stomatopods are traditionally subdivided into two branches based on the structure of their anterior appendages [26][27][28] : the well-known "smashers" that use a hammer-like club to destroy hardshell preys, and the less famous "spearers" (Figure 1a) that have a harpoon-like appendage to impale and grasp their (generally) soft-body preys. Thanks to an efficient "amplification system," which includes a dedicated area (the saddle) to store and release elastic energy, 29 together with an ingenious system of articulation, 30 stomatopods can deploy their anterior appendages at impressive velocities (up to 6 m/s for the spearers and to 23 m/s for the smashers).…”