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

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.

Precise Temporal Correlation of Holocene Mollusk Shells Using Sclerochronology

2000 ◽  
Vol 53 (2) ◽  
pp. 236-246 ◽  
Author(s):  
Thomas M. Marchitto ◽  
Glenn A. Jones ◽  
Glenn A. Goodfriend ◽  
Christopher R. Weidman
Keyword(s):  
Shell Growth ◽  
Morphological Characteristics ◽  
Temporal Correlation ◽  
Band Width ◽  
Georges Bank ◽  
Arctica Islandica ◽  
Mollusk Shells ◽  
Aspartic Acid Racemization ◽  
Geochemical Proxies ◽  
Growth Bands

AbstractAnnual growth bands of mollusk shells record several types of paleoenvironmental information, including geochemical proxies for water properties and morphological characteristics of growth and mortality. Sclerochronology, the marine counterpart of dendrochronology, offers a way to link individual shells together to form long continuous records of such parameters. It also allows for precise dating of recent shells and identification of contemporaneous fossil individuals. The longevity of the ocean quahog Arctica islandica (commonly >100 yr) makes this species well suited for sclerochronology. Band width records of contemporaneous A. islandica specimens from the same region exhibit high correlations (ρ = 0.60–0.80 for spans of ≥30 bands), indicating some common environmental influences on shell growth. By adopting several strict criteria, fossil (dead-collected) shells can be linked into composite sclerochronologies. A seven-shell 154-yr chronology was constructed for Georges Bank using three live-collected and four dead-collected shells. Band width matching indicates that the dead-collected individuals died in A.D. 1950, 1971, 1978, and 1989. Sclerochronological age assignments were verified using aspartic acid racemization dating. Construction of a 1000-yr sclerochronology is judged to be feasible using the described methods.

scholarly journals Bivalves rapidly repair shells damaged by fatigue and bolster strength

2021 ◽  
Vol 224 (19) ◽  
Author(s):  
R. L. Crane ◽  
J. L. Diaz Reyes ◽  
M. W. Denny
Keyword(s):  
Shell Growth ◽  
Fatigue Loading ◽  
Epifluorescence Microscopy ◽  
Mytilus Californianus ◽  
Environmental Threats ◽  
Rapid Repair ◽  
Shell Deposition ◽  
Repetitive Loading ◽  
Plastic Changes ◽  
Mussel Shells

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.

scholarly journals Shell mineralogy of a foundational marine species, Mytilus californianus, over half a century in a changing ocean

2021 ◽  
Vol 118 (3) ◽  
pp. e2004769118
Author(s):  
Elizabeth M. Bullard ◽  
Ivan Torres ◽  
Tianqi Ren ◽  
Olivia A. Graeve ◽  
Kaustuv Roy
Keyword(s):  
Ocean Acidification ◽  
Historical Data ◽  
Mineralogical Composition ◽  
Marine Species ◽  
Mytilus Californianus ◽  
Negative Effects ◽  
Saturation State ◽  
Long Term Changes ◽  
Time Periods

Anthropogenic warming and ocean acidification are predicted to negatively affect marine calcifiers. While negative effects of these stressors on physiology and shell calcification have been documented in many species, their effects on shell mineralogical composition remains poorly known, especially over longer time periods. Here, we quantify changes in the shell mineralogy of a foundation species, Mytilus californianus, under 60 y of ocean warming and acidification. Using historical data as a baseline and a resampling of present-day populations, we document a substantial increase in shell calcite and decrease in aragonite. These results indicate that ocean pH and saturation state, not temperature or salinity, play a strong role in mediating the shell mineralogy of this species and reveal long-term changes in this trait under ocean acidification.

Growth Bands in the sea Urchin Echinus Esculentus: Results from Tetracycline-Mark/Recapture

1992 ◽  
Vol 72 (1) ◽  
pp. 257-260 ◽  
Author(s):  
J. D. Gage
Keyword(s):  
Sea Urchin ◽  
Growth Rates ◽  
Wild Population ◽  
Sea Urchins ◽  
Middle Layer ◽  
Age And Growth ◽  
Irish Sea ◽  
Plate Edge ◽  
Growth Band ◽  
Growth Bands

Recoveries of tetracycline-labelled specimens of the sea urchin Echinus esculentus (Echinodermata: Echinoidea) from a wild population marked two years previously indicate very low skeletal growth rates in large adults. The post-tag growth in the test of a smaller specimen showed two clear growth zones in the middle layer of the plates, this conforming to the expectation of a single growth band each year. Merging of the spinochrome pigment bands present in the outer layer near the plate edge in older urchins will probably result in underestimation of age based on counts of these bands.The large literature on growth banding in the European sea urchin Echinus esculentus L. and other echinoids is reviewed by Pearse & Pearse (1975), Smith (1980) and Gage (1991). Moore (1935) utilised spinochrome pigment banding in the genital (apical) plates of E. esculentus from the Isle of Man (Irish Sea) and Firth of Clyde (western Scotland) in one of the first studies utilising growth bands to interpret the age structure and growth rates of sea urchins. A single band was assumed to be formed each year. Counts of spinochrome bands have been used to obtain nearly all subsequently published age data for this species (Sime, 1982; Nichols et al., 1985; Sime & Cranmer, 1985; Comely & Ansell, 1988).The present study was aimed at helping to resolve differing interpretations of age and growth rates in Echinus esculentus provided by these studies. This was undertaken by time marking the skeletal plates of a large sample of a wild population accessible by scuba diving on a submerged rock reef at 10–15 m depth off the islet of Eilean Mor near the Dunstaffnage Laboratory.

Assessing growth band counts from vertebrae and dorsal-fin spines for ageing sharks: comparison of four methods applied to Heterodontus portusjacksoni

2009 ◽  
Vol 60 (9) ◽  
pp. 898 ◽  
Author(s):  
Javier Tovar-Ávila ◽  
Christopher Izzo ◽  
Terence I. Walker ◽  
J. Matías Braccini ◽  
Robert W. Day
Keyword(s):  
Shark Species ◽  
Systematic Bias ◽  
Age Validation ◽  
Growth Band ◽  
Dorsal Fin ◽  
Growth Bands ◽  
Visible Growth ◽  
Port Jackson ◽  
First Time ◽  
Fin Spines

Four methods for counting growth bands using vertebrae and dorsal-fin spines of the Port Jackson shark, Heterodontus portusjacksoni, are compared. Both calcified structures presented observable growth bands, allowing cross comparison among structures for the first time in a shark species. Whole and sectioned vertebrae and dorsal fin-spines possess highly visible growth bands and intra-reader band counts resulted in similar precision indices with little systematic bias. However, inter-reader growth band count plots showed possible biases in counts from sectioned vertebrae and sectioned dorsal-fin spines. Sectioned vertebrae and whole and sectioned dorsal-fin spines produced similar growth band counts, whereas whole vertebrae produced significantly lower counts. The similar readability, precision indices, growth band counts and apparent absence of biases between counts for a single reader would indicate that sectioned vertebrae and whole and sectioned dorsal-fin spines are both potentially useful and acceptable methods for band counting. However, inter-reader comparisons are necessary to avoid acceptance of biased estimations, resulting in over- or under-estimations of age. Validation for all age classes is essential to determining accurate age estimations for this and other species.

scholarly journals Oxygen Isotope Variability within Nautilus Shell Growth Bands

PLoS ONE ◽  
2016 ◽  
Vol 11 (4) ◽  
pp. e0153890 ◽  
Author(s):  
Benjamin J. Linzmeier ◽  
Reinhard Kozdon ◽  
Shanan E. Peters ◽  
John W. Valley
Keyword(s):  
Oxygen Isotope ◽  
Shell Growth ◽  
Growth Bands

scholarly journals Alternative models for allozyme-associated heterosis in the marine bivalve Spisula ovalis.

Genetics ◽  
1995 ◽  
Vol 139 (4) ◽  
pp. 1719-1726 ◽  
Author(s):  
P David ◽  
B Delay ◽  
P Berthou ◽  
P Jarne
Keyword(s):  
Genetic Basis ◽  
Linear Models ◽  
Growth Parameters ◽  
Shell Growth ◽  
Maximum Size ◽  
Age And Growth ◽  
Individual Growth ◽  
Marine Bivalve ◽  
Initial Growth ◽  
Genomic Effects

Abstract Correlations between allozyme heterozygosity and fitness-related traits, especially growth, have been documented in natural populations of marine bivalves. However, no consistent pattern has been exhibited, because heterotic effects on size vary with age and individual growth parameters are generally unknown. No consensus has emerged on the genetic basis of allozyme-associated heterosis. The species studied here, Spisula ovalis, displays annual shell growth lines, which allows us to compute individual age and growth dynamics over the whole life span. Our morphological study was coupled to a protein electrophoresis study at seven polymorphic loci. While the maximum size gained is not related to heterozygosity, the age at half maximum size, t1/2, is significantly negatively correlated with heterozygosity, indicating an heterotic effect on initial growth. The correlation between heterozygosity and size is expected to vanish when age increases, due to the form of the growth function. This decreasing correlation is consistent with previous studies. We compare the relative performances of five linear models to analyze the genetic basis of heterosis. Surprisingly, the largest part of variance in t1/2 is due to additive effects, the overdominant components being much weaker. Heterosis is therefore due to general genomic effects rather than to local overdominance restricted to allozymes or small neighboring chromosomal segments. A significant dependence of individual heterotic contributions of the enzyme loci upon expected heterozygosities, rather than metabolic function, further supports the hypothesis of enzymes acting as markers. General genomic effects can hold only if allozyme heterozygosity is positively correlated with heterozygosity at fitness-related genes scattered throughout the genome. This hypothesis is supported here by heterozygosity correlations between enzymatic loci.

Periodicity of the growth‐band formation in vertebrae of juvenile scalloped hammerhead shark Sphyrna lewini from the Mexican Pacific Ocean

2019 ◽  
Vol 95 (4) ◽  
pp. 1072-1085 ◽  
Author(s):  
Claire Coiraton ◽  
Javier Tovar‐Ávila ◽  
Karla C. Garcés‐García ◽  
José A. Rodríguez‐Madrigal ◽  
Rodney Gallegos‐Camacho ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Band Formation ◽  
Growth Band ◽  
Mexican Pacific ◽  
Sphyrna Lewini ◽  
Hammerhead Shark ◽  
Scalloped Hammerhead

A novel statistical method for validating the periodicity of vertebral growth band formation in elasmobranch fishes

2009 ◽  
Vol 66 (5) ◽  
pp. 771-780 ◽  
Author(s):  
Hiroshi Okamura ◽  
Yasuko Semba
Keyword(s):  
Annual Cycle ◽  
Age Determination ◽  
Simulated Data ◽  
Information Criterion ◽  
Circular Data ◽  
Sample Sizes ◽  
Band Formation ◽  
Growth Band ◽  
Verification Method ◽  
Periodic Growth

A simple age verification method is presented for centrum edge analysis (CEA) of elasmobranch species. In this method, a binomial model is linked with a von Mises distribution for circular data, taking the characteristics of the CEA data into account. The periodicity of growth band pairs is categorized as no cycle, an annual cycle, or a biannual cycle. Three models are then constructed according to different periodicities. We use the Akaike information criterion (AIC) to determine which model is the best. The models were applied to the shortfin mako shark ( Isurus oxyrinchus ) data collected in the North Pacific to identify the best periodicity model. The AIC best-fitting model was one involving an annual cycle. The general performance of the method was evaluated using simulated data of various sample sizes, formation times, and durations of growth band pairs. The simulation trials showed that the performance of the method was satisfactory with moderate sample sizes. This method should improve the accuracy of age determination and could be applied to all species that have periodic growth band pairs.

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