A mathematical model for the mechanical properties of scallop shells

Pennington, B. J.; Currey, John D.

doi:10.1111/j.1469-7998.1984.tb05953.x

Cited by 24 publications

(11 citation statements)

References 15 publications

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“…In general, it is suggested that the shell strength in scallops is a function of shell height, thickness, corrugation, and convexity of the whole shell 52 . In mollusks, experimental and natural low pH conditions alter shell size and thickness 30 , 32 , 53 , and several studies reported that low pH reduces the shell breaking strength in oysters 54 and mussels 40 , 55 .…”

Section: Discussionmentioning

confidence: 99%

Plasticity in organic composition maintains biomechanical performance in shells of juvenile scallops exposed to altered temperature and pH conditions

Lagos

Benítez

Grenier

et al. 2021

Sci Rep

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The exposure to environmental variations in pH and temperature has proven impacts on benthic ectotherms calcifiers, as evidenced by tradeoffs between physiological processes. However, how these stressors affect structure and functionality of mollusk shells has received less attention. Episodic events of upwelling of deep cold and low pH waters are well documented in eastern boundary systems and may be stressful to mollusks, impairing both physiological and biomechanical performance. These events are projected to become more intense, and extensive in time with ongoing global warming. In this study, we evaluate the independent and interactive effects of temperature and pH on the biomineral and biomechanical properties of Argopecten purpuratus scallop shells. Total organic matter in the shell mineral increased under reduced pH (~ 7.7) and control conditions (pH ~ 8.0). The periostracum layer coating the outer shell surface showed increased protein content under low pH conditions but decreasing sulfate and polysaccharides content. Reduced pH negatively impacts shell density and increases the disorder in the orientation of calcite crystals. At elevated temperatures (18 °C), shell microhardness increased. Other biomechanical properties were not affected by pH/temperature treatments. Thus, under a reduction of 0.3 pH units and low temperature, the response of A. purpuratus was a tradeoff among organic compounds (biopolymer plasticity), density, and crystal organization (mineral plasticity) to maintain shell biomechanical performance, while increased temperature ameliorated the impacts on shell hardness. Biopolymer plasticity was associated with ecophysiological performance, indicating that, under the influence of natural fluctuations in pH and temperature, energetic constraints might be critical in modulating the long-term sustainability of this compensatory mechanism.

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Section: Discussionmentioning

confidence: 99%

Plasticity in organic composition maintains biomechanical performance in shells of juvenile scallops exposed to altered temperature and pH conditions

Lagos

Benítez

Grenier

et al. 2021

Sci Rep

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“…Having obtained such mechanics‐based predation map, it would be of great interest to locate the corresponding regions of the real mollusk shells on this map. By referring to the data reported in the literature,34–37 we located the positions in the predation map for shells of some common mollusks from both freshwater and ocean, as shown in Figure 6. It is interesting to notice that all freshwater mollusk species we chose at random, including, L. stagnalis and C. chinensis (pond snail), fall in region I while marine species distribute in both regions I and III, implying that the teeth of black carp cater for predation of freshwater mollusks.…”

Section: Mechanics‐based Predation Map Of Black Carpmentioning

confidence: 99%

Mechanics of Pharyngeal Teeth of Black Carp (Mylopharyngodon piceus) Crushing Mollusk Shells

He¹,

Zhou²,

Wang³

et al. 2013

Adv Eng Mater

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Mollusks such as snail and mussels adopt hard shells to protect their vulnerable bodies. Recent studies on biomaterials have revealed that these shells especially the nacre layers exhibit excellent mechanical properties, inspiring a number of biomimetic endeavors. Nevertheless, in nature, there is a species of fish called Mylopharyngodon piceus or black carp, whose main diet is exactly snails and mussels. Does such unique diet imply that the pharyngeal teeth of black carp, its major masticatory apparatus, are superior to the mollusk shells in mechanical properties? In this paper, structural and mechanical characterizations are conducted on the pharyngeal teeth of black carp, showing that enameloid, the outermost layer of black carp teeth, possesses similar elastic modulus and hardness in comparison to those of the pond snail shells. To shed light on the mechanics underlying the capability of pharyngeal teeth to crush mollusk shells, parametric studies on the geometry of the shells are conducted by means of finite element method. It is found that whether a mollusk shell is crushable or not, for given pharyngeal teeth, depends on the radius (R) and thickness (t) of the shell. A predation map for black carp teeth is constructed by delimiting the t–R plane into three phasic regions corresponding to three possible consequences of the mechanical competition between pharyngeal teeth and shells. It is interesting to notice that all the freshwater shells chosen at random fall in the crushable regime while the seashells do not necessarily. This feature of black carp teeth can be speculated as a result of evolution in response to its freshwater diet.

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“…Strongly plicate margins in marine bivalves are almost all restricted to epifaunal and shallowly infaunal species, including members of the Pectinidae, Plicatulidae, Anomiidae (Placunanomia), Ostreoidea, Pinnidae, Mytilidae (the Miocene North Pacific Plicatomytilus), Carditidae, Donacidae (Tridonax), Chamidae (Arcinella), post-Triassic Trigonioidea and Mesozoic Inoceramidae (Yoshida, 1998;Savazzi & Sa¨lgeback, 2004;Huber, 2010). Whether the folded margin itself functions in these bivalves is unclear, but the external sculptural elements generated by it serve to stiffen the valves against bending (Reif, 1978;Pennington & Currey, 1984;Alexander, 1990a, b;Savazzi & Sa¨lgeback, 2004). Similar stiffening, but then without marginal deviations, occurs in concentrically corrugated, thin-shelled, slow-burrowing mactrids such as Harvella, Mactrinula, Raeta and Raetellops (see also Morton, 2010;Signorelli, 2013) as well as in some thraciids, inoceramids and the Middle Permian genus Kolymia (Checa & Crampton, 2002;Biakov, 2012).…”

Section: Other Marginal Modificationsmentioning

confidence: 99%

Molluscan marginalia: hidden morphological diversity at the bivalve shell edge

Vermeij

2013

Journal of Molluscan Studies

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Molluscan shells exhibit a high and largely neglected diversity of serrations and crenulations at the growing margin. A survey of living and Cenozoic fossil bivalves indicates that serrations, in which the external ribs or interspaces between ribs extend radially beyond the general contour of the valve margin, may be symmetrical or asymmetrical. Projections whose adumbonal edge more nearly parallels the shell edge than the abumbonal edge occur on the posterior valve margins of many limids, cardiids and donacids, as well as in the arcid Anadara and a few concentrically ridged tellinids. In many cardiids, posterior serrations form as extensions of ribs, whereas ventral and anterior projections are extensions of rib interspaces. Asymmetrical serrations are almost always found on shell edges that are polished, indicating that the mantle extends slightly over the valve margin to the outside. I tentatively suggest that asymmetrical serrations enable the valves to close around siphons or other mantle extensions without injuring these soft tissues, so that the bivalve can maintain sensory contact with the environment even while the shell is shut. A preliminary comparison with brachiopods indicates that the diversity of conditions at the shell edge is much higher in bivalves. Together with the largely warm-water and marine distribution of marginal modifications in bivalves, these comparisons reflect the higher metabolic potentials of bivalves relative to brachiopods, and show that the shell edge is a rich source of evidence about function and mode of life in fossils.

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A mathematical model for the mechanical properties of scallop shells

Cited by 24 publications

References 15 publications

Plasticity in organic composition maintains biomechanical performance in shells of juvenile scallops exposed to altered temperature and pH conditions

Plasticity in organic composition maintains biomechanical performance in shells of juvenile scallops exposed to altered temperature and pH conditions

Mechanics of Pharyngeal Teeth of Black Carp (Mylopharyngodon piceus) Crushing Mollusk Shells

Molluscan marginalia: hidden morphological diversity at the bivalve shell edge

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