Bivalves rapidly repair shells damaged by fatigue and bolster strength

ABSTRACT Hard external armors have to defend against a lifetime of threats yet are traditionally understood by their ability to withstand a single attack. Survival of bivalve mollusks thus can depend on the ability to repair shell damage between encounters. We studied the capacity for repair in the intertidal mussel Mytilus californianus by compressing live mussels for 15 cycles at ∼79% of their predicted strength (critically fracturing 46% of shells), then allowing the survivors 0, 1, 2 or 4 weeks to repair. Immediately after fatigue loading, mussel shells were 20% weaker than control shells that had not experienced repetitive loading. However, mussels restored full shell strength within 1 week, and after 4 weeks shells that had experienced greater fatiguing forces were stronger than those repetitively loaded at lower forces. Microscopy supported the hypothesis that crack propagation is a mechanism of fatigue-caused weakening. However, the mechanism of repair was only partially explained, as epifluorescence microscopy of calcein staining for shell deposition showed that only half of the mussels that experienced repetitive loading had initiated direct repair via shell growth around fractures. Our findings document repair weeks to months faster than demonstrated in other mollusks. This rapid repair may be important for the mussels’ success contending with predatory and environmental threats in the harsh environment of wave-swept rocky coasts, allowing them to address non-critical but weakening damage and to initiate plastic changes to shell strength. We highlight the significant insight gained by studying biological armors not as static structures but, instead, as dynamic systems that accumulate, repair and respond to damage.

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Testing hypotheses concerning the formation of shell growth marks in marine pelecypods

Canadian Journal of Zoology ◽

10.1139/z91-081 ◽

1991 ◽

Vol 69 (3) ◽

pp. 535-546 ◽

Cited By ~ 6

Author(s):

Edwin Bourget ◽

Hélène Bérard ◽

Vibeke Brock

Keyword(s):

Shell Growth ◽

Growth Accounting ◽

Short Term ◽

Tidal Period ◽

Growth Increments ◽

Potential Sources ◽

Sources Of Variation ◽

Shell Deposition ◽

The Individual ◽

External Growth

This paper reviews the evidence supporting the current hypotheses (daily, tidal, endogenous, and other rhythms of growth) accounting for short-term periodicity in the formation of marks (external growth ridges and internal growth increments) on the shell of marine pelecypod molluscs. With few exceptions our analysis shows too much unexplained variability and the availability of too few studies of potential sources of variation for the proposed cycles of mark formation (circadian, circatidal) to be accepted. Since shell deposition takes the form of marks, which must be discrete in frequency (0, 1, or 2 per given day or tidal period), we submit that individual frequencies must be used to test hypotheses concerning the rhythms of shell growth mark formation, and we propose the use of three criteria: (i) that departure of the individual measured frequency from the expected frequency should not be more than the maximal error in measurements (maximal counting errors made by the observer); (ii) should condition one be violated, then the so-called "missing" or "superfluous" marks should be clearly accounted for; (iii) that potential sources of variation (e.g., age, habitat, locality, season) should not significantly influence the frequency of formation of the marks.

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Oxygen and carbon stable isotopes of Mytilus galloprovincialis Lamarck, 1819 shells as environmental and provenance proxies

The Holocene ◽

10.1177/0959683619865595 ◽

2019 ◽

Vol 30 (1) ◽

pp. 65-76 ◽

Cited By ~ 2

Author(s):

Stefania Milano ◽

Bernd R Schöne ◽

Igor Gutiérrez-Zugasti

Keyword(s):

Stable Isotopes ◽

Mytilus Galloprovincialis ◽

Shell Growth ◽

Geochemical Data ◽

Carbon Stable Isotopes ◽

Northern Spain ◽

Mollusc Shell ◽

Geochemical Composition ◽

Mussel Shells ◽

Geochemical Analyses

Mollusc shell stable isotopes are commonly used to reconstruct past environmental conditions. However, despite being abundant components of natural and anthropogenic fossil accumulations, the geochemical composition of mussel shells ( Mytilus spp.) has rarely received attention in palaeoenvironmental studies. This study tests the suitability of oxygen isotopes (δ18Os) of Mytilus galloprovincialis as palaeothermometer. For 1 year, mussels and water samples were collected twice a month from Berria Beach, in Northern Spain. The geochemical data of the shells indicate that water temperatures can be reconstructed with an average offset of 1.2 ± 0.7°C with respect to the measured values. Furthermore, no prolonged shell growth cessations are observed. These results validate M. galloprovincialis as reliable recorders of seasonal water temperature fluctuations, supporting their use in palaeoenvironmental studies. In addition, further shell and water collections were carried out in the upper and lower areas of a nearby estuary. The geochemical analyses of these shells were aimed to test whether oxygen and carbon stable isotopes (δ13Cs) may be used as novel proxies to identify the shell provenance at local scale. The results show that the δ18Os versus δ13Cs correlation direction varies along the coast–upper estuary geographical gradient, suggesting it to be a potential new proxy to distinguish between marine and estuarine mussel specimens.

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Regulation of shell growth in the pulmonate gastropod Helisoma duryi

Canadian Journal of Zoology ◽

10.1139/z78-265 ◽

1978 ◽

Vol 56 (9) ◽

pp. 1975-1980 ◽

Cited By ~ 14

Author(s):

S. C. Kunigelis ◽

A. S. M. Saleuddin

Keyword(s):

Shell Growth ◽

Relative Proportion ◽

Continuous Light ◽

Continuous Darkness ◽

Deposition Rates ◽

Factors Affecting ◽

Helisoma Duryi ◽

Shell Deposition ◽

Slow Growing ◽

Pulmonate Gastropod

Photoperiod has a significant effect on linear shell deposition rates; animals maintained in continuous darkness (DD) deposit shell more rapidly than those held in continuous light (LL) or 12L: 12D. Shell deposition is endogenously governed and might be synchronized by photoperiod. Photoperiod also affects the relative proportion of shell occupied by different crystal layers.Injections of brain homogenates from fast-growing animals stimulate shell deposition in slow-growing animals. Supraoesophageal and suboesophageal brain fractions both have a greater effect than whole brain; both fractions may contain factors affecting shell growth. Suboesophageal fractions from shell-repairing donors show a reduced effect. A supraoesophageal factor may be involved in normal shell growth and a suboesophageal factor in shell repair.

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Investigating controls of shell growth features in a foundation bivalve species: seasonal trends and decadal changes in the California mussel

10.5194/bg-2021-219 ◽

2021 ◽

Author(s):

Veronica Padilla Vriesman ◽

Sandra J. Carlson ◽

Tessa M. Hill

Keyword(s):

Shell Structure ◽

Shell Growth ◽

Mineralogical Composition ◽

Mytilus Californianus ◽

Marine Bivalve ◽

Band Formation ◽

Growth Band ◽

Dark Light ◽

Environmental Controls ◽

Growth Bands

Abstract. Marine bivalve mollusc shells can offer valuable insights into past oceanographic variability and seasonality. Given its ecological and archaeological significance, Mytilus californianus (California mussel) presents the opportunity to examine seasonal and decadal changes recorded in its shell over centuries to millennia. While dark–light growth bands in M. californianus shells could be advantageous for reconstructing past environments, uncertainties remain regarding shell structure, environmental controls of dark–light band formation, and the amount of time represented by a dark–light pair. By analyzing a suite of M. californianus shells collected in 2002, 2003, 2019, and 2020 from Bodega Bay, California, we describe the mineralogical composition, establish relationships among growth band pattern, micro-environment, and collection season, and compare shell structure and growth band expression between the archival (2002–2003) and modern (2019–2020) shells. We identified three mineralogical layers in M. californianus: an outer prismatic calcite layer, a middle aragonite layer, and a secondary inner prismatic calcite layer, which makes M. californianus the only Mytilus species to precipitate a secondary calcite layer. Within the inner calcite layer, light bands are strongly correlated with winter collection months and could be used to reconstruct periods with moderate, stable temperatures and minimal upwelling. Additionally, modern shells have significantly thinner inner calcite layers and more poorly expressed growth bands than the archival shells, although we also show that growth band contrast is strongly influenced by micro–environment. Mytilus californianus from northern California is calcifying differently, and apparently more slowly, than it was 20 years ago.

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Predator-induced shell plasticity in mussels hinders predation by drilling snails

10.1101/124784 ◽

2017 ◽

Author(s):

Zachary T. Sherker ◽

Julius A. Ellrich ◽

Ricardo A. Scrosati

Keyword(s):

Shell Growth ◽

Handling Time ◽

Shell Mass ◽

Nonconsumptive Effects ◽

Trade Off ◽

Predator Cues ◽

Structural Modifications ◽

Invertebrate Prey ◽

Sessile Invertebrate ◽

Mussel Shells

ABSTRACTSessile invertebrate prey that detect waterborne predator cues often respond by strengthening their structural defenses. Experimental evidence of the functional significance of such modifications using field-raised organisms is lacking. This study addresses that gap using intertidal mussels and predatory dogwhelks from Atlantic Canada. During the spring and summer of 2016, we ran a field experiment that manipulated dogwhelk presence to test their nonconsumptive effects on mussel traits. Dogwhelk cues elicited thickening at the lip, centre, and base of mussel shells, although simultaneously limiting shell growth in length. As shell mass was unaffected by dogwhelk presence, a trade-off between shell thickening and elongation was revealed. Thickening was strongest at the thinnest parts of the shell. Using the field-raised organisms, a lab experiment found that dogwhelks took, on average, 55 % longer to drill and consume mussels previously exposed to dogwhelk cues than mussels grown without such a cue exposure. Dogwhelks drilled at the thinnest parts of the shell but, nonetheless, the consumed cue-exposed mussels had thicker shells at the borehole than the consumed mussels not exposed to cues, which likely explains the observed difference in handling time. As handling time normally decreases predation success, this study indicates that the plastic structural modifications in mussels triggered by dogwhelk cues in the field hinder predation by these drilling predators.

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Effect of Fatigue Loading on Tendon Fascicle Extension Mechanisms

Volume 1B: Extremity; Fluid Mechanics; Gait; Growth, Remodeling, and Repair; Heart Valves; Injury Biomechanics; Mechanotransduction and Sub-Cellular Biophysics; MultiScale Biotransport; Muscle, Tendon and Ligament; Musculoskeletal Devices; Multiscale Mechanics; Thermal Medicine; Ocular Biomechanics; Pediatric Hemodynamics; Pericellular Phenomena; Tissue Mechanics; Biotransport Design and Devices; Spine; Stent Device Hemodynamics; Vascular Solid Mechanics; Student Paper and Design Competitions ◽

10.1115/sbc2013-14009 ◽

2013 ◽

Author(s):

Chavaunne T. Thorpe ◽

Helen L. Birch ◽

Peter D. Clegg ◽

Hazel R. C. Screen

Keyword(s):

Achilles Tendon ◽

Fatigue Loading ◽

Cyclic Fatigue ◽

Tendon Injury ◽

Sudden Onset ◽

Applied Strain ◽

Strain Response ◽

Onset Condition ◽

Energy Store ◽

Repetitive Loading

Tendon injury is common, probably occurring due to accumulation of microdamage within the tendon matrix as a result of repetitive loading rather than as a sudden onset condition 1. The human Achilles tendon is highly susceptible to injury; this tendon functions as an energy store and experiences high stresses and strains during normal use 2. The equine superficial digital flexor (SDFT) is also an energy storing tendon and is highly injury prone, therefore it is often used as a model to study structure function relationships within this type of tendon 3. Our previous work has characterized the microstructural response of SDFT fascicles to applied strain, with results indicating the presence of a helical component to the fascicle which may facilitate extension by unwinding of the coil 4. The aim of this study was to assess the effect of cyclic fatigue loading (creep) on the microstructural strain response of the equine SDFT to test the hypothesis that fatigue loading would result in altered fascicle extension mechanisms.

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Tidal micro-growth bands in intertidal gastropod shells, with an evaluation of band-dating techniques

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1982.0013 ◽

1982 ◽

Vol 214 (1196) ◽

pp. 305-323 ◽

Cited By ~ 30

Keyword(s):

Reliable Method ◽

Sea Water ◽

Shell Growth ◽

Littorina Littorea ◽

Nucella Lapillus ◽

Surface Check ◽

Growth Bands ◽

Intertidal Gastropod ◽

Shell Deposition ◽

Made In

Four methods were used in dating micro-growth bands in the intertidal gastropods Littorina littorea, Patella vulgata and Nucella lapillus. One of the methods employed, immersion in 2.25 x 10 -4 M acetazolamide, was always successful in producing a stress band by inhibiting shell growth, but in Littorina littorea and Nucella lapillus the inhibition persisted for several days after treatment and reduced the number of bands subsequently laid down. A surface check mark associated with an internal stress band could be made in a percentage of all three species if they were kept at 3°C for 3–4 days. However, this treatment was damaging to Nucella lapillus . The most reliable method for dating the bands without appreciably interrupting subsequent shell deposition was to remove mechanically a thin layer from the outer lip of the shell or to keep the animals in sea water with ample food for 36 h to produce an abnormally wide shell increment. When the last two methods were used and the number of bands from the check band to the growing edge were counted in peels of sectioned and etched shells, the number agreed within 1% with the number of low waters that the animals had experienced.

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