Abstract
Genetic responses of oysters to specific environments underpin adaptation and evolutionary potential, which can be leveraged through breeding to improve outcomes. Shell traits strongly influence both survival and market value in the half-shell market. Using novel trait phenotyping methods, the heritability, genetics-by-environment interactions, and potential surrogate traits for shell integrity (hardness, chalkiness, density, compressive strength) and other market-preferred phenotypes were investigated in twenty full-sib pedigree-bred Pacific oyster family lines. Of twenty traits assessed, shell colour had the highest heritability ((:{h}^{2}) = 0.93, 0.78, in faster- and slower-growth estuaries respectively). Shell integrity traits exhibited moderate heritabilities ((:{h}^{2})=0.12–0.40), growth traits had low to moderate heritabilities ((:{h}^{2}) = 0.08– 0.26), and meat yield/condition had values near zero. Higher trait heritabilities were identified for many morphometric and somatic metrics, as well as meat yield phenotypes, in the slower-growth estuary. The faster-growth estuary had higher heritabilities for shell colour and density. Phenotypic expression under reduced growth aligned with industry-favourable shell qualities, including denser, darker, less brittle shells with deeper cups, whereas fast growth produced diminished shell integrity but with superior meat yield. Genetic correlations indicate that selection on readily measurable whole, shell and meat weight traits, alongside colour, could improve shell integrity, reduce production losses and enable farmers to consistently deliver better-quality oysters to market.
Data availability
The data supporting the findings of this study are available and will be made available upon resonable request to the corresponding author.
References
Mizuta, D. D. & Wikfors, G. H. Seeking the perfect oyster shell: a brief review of current knowledge. Rev. Aquac. 11, 586–602 (2019).
van Houcke, J., Altintzoglou, T., Linssen, J. & Luten, J. Quality perception, purchase intention, and the impact of information on the evaluation of refined Pacific cupped oysters (Crassostrea gigas) by Dutch consumers. J. Sci. Food Agric. 98, 4778–4785 (2018).
Yuan, B. et al. Consumer preferences for oyster trait attributes in china: A choice experiment. Aquaculture 571, 739471 (2023).
Lombardi, S. A., Chon, G. D., Lee, J. J. W., Lane, H. A. & Paynter, K. T. Shell hardness and compressive strength of the Eastern oyster, Crassostrea virginica, and the Asian oyster, Crassostrea Ariakensis. Biol. Bull. 225, 175–183 (2013).
Chuku, E. O., Rust, S. A., Smith, G. G., Mazumder, D. & Trotter, A. J. Discovering a model Pacific oyster for sustainable aquaculture production and sales optimisation in Southern Australia. Front. Sustain. Food Syst. 8, 1–16 (2024).
Chuku, E. O., Smith, G. G., Mazumder, D., Rust, S. A. & Trotter, A. J. Effect of intertidal air exposure and handling husbandries on shell development, meat condition and survival of farmed Pacific oysters (Magallana gigas, Thunberg 1793). Aquaculture 605, (2025).
Whittington, R. J., Dhand, N. K., Evans, O. & Paul-Pont, I. Further observations on the influence of husbandry practices on OsHV-1 µVar mortality in Pacific oysters Crassostrea gigas: Age, cultivation structures and growing height. Aquaculture 438, 82–97 (2015).
Yang, Q. et al. Shell characterization and effects on cavity volume of wild Jinjiang oyster Crassostrea Ariakensis in different estuaries of China. J. Oceanol. Limnol. 41, 2020–2031 (2023).
Kube, P. et al. Enhancement Pac. Oyster Selective Breed. Program (2011).
Ward, R. D., Thompson, P. A., Appleyard, S. A., Swan, A. A. & Kube, P. D. Sustainable Genetic Improvement of Pacific Oysters in Tasmania and South Australia. Fisheries Research and Development Corporation (Australia) (2005). http://frdc.com.au/Archived-Reports/FRDCProjects/2000-206-DLD.pdf
Kong, N., Li, Q., Yu, H. & Kong, L. F. Heritability estimates for growth-related traits in the Pacific oyster (Crassostrea gigas) using a molecular pedigree. Aquac Res. 46, 499–508 (2015).
Xu, L., Li, Q., Yu, H. & Kong, L. Estimates of heritability for growth and shell color traits and their genetic correlations in the black shell strain of Pacific oyster Crassostrea gigas. Mar. Biotechnol. 19, 421–429 (2017).
Vu, S. V. et al. Genomic prediction for whole Weight, body Shape, meat Yield, and color traits in the Portuguese oyster Crassostrea angulata. Front Genet 12, (2021).
Pang, Y., Ono, T. & Tanaka, T. Environmental effects on growth performance of Pacific oyster Crassostrea gigas cultured in the Seto inland Sea, Japan, from 1990 to 2021. Fish. Oceanogr. https://doi.org/10.1111/fog.12686 (2024). 10.1111/fog.12686
Caretti, O. N., Eggleston, D. B., Puckett, B. J. & Bohnenstiehl, D. W. R. Location and reef size drive oyster reef restoration success. Restor Ecol 32, (2024).
Bai, Y. et al. Multi-omic insights into the formation and evolution of a novel shell microstructure in oysters. BMC Biol 21, (2023).
Vu, S. V. et al. Genetic parameters for traits affecting consumer preferences for the Portuguese oyster, Crassostrea angulata. Aquaculture 526, (2020).
Jiang, K. et al. Genetic improvement of oysters: Current status, challenges, and prospects. Reviews in Aquaculture vol. 16 796–817 Preprint at (2024). https://doi.org/10.1111/raq.12868
Chi, Y., Li, Q. & Xu, C. Genetic parameters and genotype by environment interactions for harvest traits in the Pacific oyster (Crassostrea gigas). Aquacult. Int. 32, 175–195 (2024).
He, X. et al. A genome-wide association study to identify the genes associated with shell growth and shape-related traits in Crassostrea gigas. Aquaculture 543, (2021).
Checa, A. G., Harper, E. M. & González-Segura, A. Structure and crystallography of foliated and chalk shell microstructures of the oyster magallana: the same materials grown under different conditions. Sci. Rep. 8, 1–12 (2018).
Checa, A. G., Rodríguez-Navarro, A. B. & Esteban-Delgado, F. J. The nature and formation of calcitic columnar prismatic shell layers in Pteriomorphian bivalves. Biomaterials 26, 6404–6414 (2005).
Strąg, M. et al. Anisotropy of mechanical properties of pinctada margaritifera mollusk shell. Nanomaterials 10, (2020).
Stenger, P. L., Vidal-Dupiol, J., Reisser, C., Planes, S. & Ky, C. L. Colour plasticity in the shells and pearls of animal graft model pinctada margaritifera assessed by HSV colour quantification. Sci. Rep. 9, 1–10 (2019).
Telesca, L., Linsley, B. K., Witek, L. & Hönisch, B. Biomineralization and Biomechanical trade-offs under heterogeneous environments in the Eastern oyster Crassostrea Virginica. Journal Molluscan Studies 90, (2024).
Frehner, C., Mennicke, R., Gattiker, F. & Chai, D. Advancements of Ultrasonic Contact Impedance (UCI) Hardness Testing Based on Continuous Load Monitoring during the Indentation Process, and Practical Benefits. http://www.ndt.net/?id=22262
Gogolinskii, K. V., Syasko, V. A., Umanskii, A. S., Nikazov, A. A. & Bobkova, T. I. Mechanical properties measurements with portable hardness testers: Advantages, limitations, prospects. in Journal of Physics: Conference Series vol. 1384IOP Publishing Ltd, (2019).
Crawford, C., Mitchell, I. & Brown, A. FINAL REPORT TO THE FISHERIES RESEARCH AND DEVELOPMENT CORPORATION FRDC GRANT 92/54 PREDICTIVE MODELLING OF CARRYING CAPACITIES OF OYSTER (CRASSOSTREA GIGAS) FARMING AREAS IN TASMANIA FISHERIES Primary Industry and Fisheries. (1996).
Doiron, S. A Reference Manual for Oyster Aquaculturists (New Brunswick, 2008).
Mazón-Suástegui, J. M., Ruíz-García, M. C., Chávez-Villalba, J., Rodríguez-Jaramillo, C. & Saucedo, P. E. Analysis of growth and first reproduction of hatchery-reared juvenile Cortez oyster (Crassostrea corteziensis) in Northwestern mexico: proposal of a minimal fishing size. Aquac Res. 42, 1558–1568 (2011).
Grizzle, R. E. et al. Growth, morphometrics and nutrient content of farmed Eastern oysters, Crassostrea Virginica (Gmelin), in new Hampshire, USA. Aquac Res. 48, 1525–1537 (2017).
Pernet, F., Lagarde, F., Gall, P., Le & D’Orbcastel, E. R. Associations between farming practices and disease mortality of Pacific oyster Crassostrea gigas in a mediterranean lagoon. Aquac Environ. Interact. 5, 99–106 (2014).
Shi, J., Kajtar, J. B., Hayashida, H. & Ugalde, S. C. Relationships between high temperatures and Pacific oyster disease and mortality in Southeast Tasmania, Australia. Cont Shelf Res 273, (2024).
Lebreton, B., Beseres Pollack, J., Blomberg, B., Palmer, T. A. & Montagna, P. A. Oyster growth across a salinity gradient in a shallow, subtropical Gulf of Mexico estuary. Exp Results 2, (2021).
La Peyre, J. F., Casas, S. M. & Supan, J. E. Effects of controlled air exposure on the survival, growth, condition, pathogen loads and refrigerated shelf life of Eastern oysters. Aquac Res. 49, 19–29 (2018).
Legat, J. F. A. et al. Crescimento e sobrevivência Da Ostra de fundo, Crassostrea gasar, cultivada no Nordeste e Sul do Brasil. Bol. Do Instituto De Pesca. 43, 172–184 (2017).
Kawabe, S., Takada, M., Shibuya, R. & Yokoyama, Y. Biochemical changes in oyster tissues and hemolymph during long-term air exposure. Fish. Sci. 76, 841–855 (2010).
Chiefa, F. et al. Comparative analysis of two different immersion times in the farming systems for Ostrea edulis and Magallana (Crassostrea) gigas in a brackish basin of Valli di Comacchio (northern Italy). Aquaculture 598, (2025).
Cilenti, L. et al. Quality aspects of Crassostrea gigas (Thunberg, 1793) reared in the Varano lagoon (southern Italy) in relation to marketability. J. Mar. Biol. Association United Kingd. 98, 71–79 (2018).
Rankin, C., Moltschaniwskyj, N., Morton, J. & Wilkie, E. Shell shape and meat condition in selectively bred Sydney rock oysters, Saccostrea glomerata (Gould, 1850): the influence of grow-out methods. Aquac Res. 49, 1189–1199 (2018).
McAfee, D., O’Connor, W. A. & Bishop, M. J. Fast-growing oysters show reduced capacity to provide a thermal refuge to intertidal biodiversity at high temperatures. J. Anim. Ecol. 86, 1352–1362 (2017).
Higgins, C. B., Stephenson, K. & Brown, B. L. Nutrient bioassimilation capacity of aquacultured oysters: quantification of an ecosystem service. J. Environ. Qual. 40, 271–277 (2011).
MacDonald, J., Freer, A. & Cusack, M. Alignment of crystallographic c-Axis throughout the four distinct microstructural layers of the oyster Crassostrea gigas. Cryst. Growth Des. 10, 1243–1246 (2010).
Kempf, H. L., Gold, D. A. & Carlson, S. J. Investigating the Relationship between Growth Rate, Shell Morphology, and Trace Element Composition of the Pacific Littleneck Clam (Leukoma staminea): Implications for Paleoclimate Reconstructions. Minerals 13, (2023).
Lagos, N. A. et al. Effects of temperature and ocean acidification on shell characteristics of argopecten purpuratus: implications for scallop aquaculture in an upwelling-influenced area. Aquac Environ. Interact. 8, 357–370 (2016).
Lord, J. P. & Whitlatch, R. B. Inducible defenses in the Eastern oyster Crassostrea Virginica Gmelin in response to the presence of the predatory oyster drill Urosalpinx cinerea say in long Island sound. Mar. Biol. 159, 1177–1182 (2012).
Sanford, E. et al. Ocean acidification increases the vulnerability of native oysters to predation by invasive snails. Proceedings of the Royal Society B: Biological Sciences 281, (2014).
Banker, R. M. W. & Sumner, D. Y. Structure and distribution of Chalky deposits in the Pacific oyster using x-ray computed tomography (CT). Sci. Rep. 10, 1–13 (2020).
Pogoda, B. et al. Site selection for biogenic reef restoration in offshore environments: the natura 2000 area Borkum reef ground as a case study for native oyster restoration. Aquat. Conserv. 30, 2163–2179 (2020).
Donelan, S. C., Breitburg, D. & Ogburn, M. B. Context-dependent carryover effects of hypoxia and warming in a coastal ecosystem engineer. (2021). https://doi.org/10.1002/eap doi:10.1002/eap.
Lyubas, A. A. et al. Impact of aquatic habitat environment on the elemental composition and shell shape variability of the Beringian freshwater mussel Beringiana Beringiana (Bivalvia, Unionidae). Ecol. Montenegrina. 66, 120–143 (2023).
Upadhyay, A., Thiyagarajan, V. & Tong, Y. Open access hypothesis proteomic characterization of oyster shell organic matrix proteins (OMP). Bioinformation 12, 266–278 (2016).
Sun, J. et al. The effect of NF-κB signalling pathway on expression and regulation of nacrein in Pearl Oyster, pinctada fucata. PLoS One 10, (2015).
Marie, B. et al. The shell-forming proteome of Lottia gigantea reveals both deep conservations and lineage-specific novelties. FEBS J. 280, 214–232 (2013).
Xue, Q., Beguel, J. P. & La Peyre, J. Dominin and Segon form multiprotein particles in the plasma of Eastern oysters (Crassostrea virginica) and are likely involved in shell formation. Front Physiol 10, (2019).
Miyamoto, H., Miyoshi, F. & Kohno, J. The carbonic anhydrase domain protein nacrein is expressed in the epithelial cells of the mantle and acts as a negative regulator in calcification in the mollusc pinctada fucata. Zoolog Sci. 22, 311–315 (2005).
Speights, C. J., Silliman, B. R. & McCoy, M. W. The effects of elevated temperature and dissolved ρCO2 on a marine foundation species. Ecol. Evol. 7, 3808–3814 (2017).
Evans, S., Camara, M. D. & Langdon, C. J. Heritability of shell pigmentation in the Pacific oyster, Crassostrea gigas. Aquaculture 286, 211–216 (2009).
Loose, S. M., Peschel, A. & Grebitus, C. Quantifying effects of convenience and product packaging on consumer preferences and market share of seafood products: the case of oysters. Food Qual. Prefer. 28, 492–504 (2013).
Loose, S., Peschel, A. & Grebitus, C. Influence of convenience on healthy food choice: The case of seafood. in Selected Paper prepared for presentation at the Agricultural & Applied Economics Association 2012 AAEA, CAES, & WAEA Joint Annual Meeting 1–8Seattle, Washington, (2012).
Gutierrez, A. P., Matika, O., Bean, T. P. & Houston, R. D. Genomic selection for growth traits in Pacific oyster (Crassostrea gigas): potential of Low-Density marker panels for breeding value prediction. Front. Genet. 9, 1–9 (2018).
Dégremont, L. Size and genotype affect resistance to mortality caused by OsHV-1 in Crassostrea gigas. Aquaculture 416–417, 129–134 (2013).
Vu, S. V. et al. First breeding program of the Portuguese oyster Crassostrea angulata demonstrated significant selection response in traits of economic importance. Aquaculture 518, (2020).
Allen, S. K., Small, J. M. & Kube, P. D. Genetic parameters for Crassostrea virginica and their application to family-based breeding in the mid-Atlantic, USA. Aquaculture 538, (2021).
Gutierrez, A. P. et al. Potential of genomic selection for improvement of resistance to ostreid herpesvirus in Pacific oyster (Crassostrea gigas). Anim. Genet. 51, 249–257 (2020).
Gutierrez, A. P. et al. A genome-wide association study for host resistance to ostreid herpesvirus in Pacific oysters (Crassostrea gigas). G3: Genes, Genomes, Genetics 8, 1273–1280 (2018).
Haworth, C. M. A. et al. Stability and change in genetic and environmental influences on well-being in response to an intervention. PLoS One 11, (2016).
Briley, D. A. & Tucker-Drob, E. M. Genetic and environmental continuity in personality development: A meta-analysis. Psychol. Bull. 140, 1303–1331 (2014).
Sheng, L. et al. Heritability estimates for nutritional quality-related traits of the Pacific oyster, Crassostrea gigas. J. World Aquac Soc. 50, 738–748 (2019).
Hedgecock, D., Shin, G., Gracey, A. Y., van den Berg, D. & Samanta, M. P. Second-generation linkage maps for the pacific oyster Crassostrea gigas reveal errors in assembly of genome scaffolds. G3: Genes, Genomes, Genetics 5, 2007–2019 (2015).
Vu, S. V. et al. Prediction accuracies of genomic selection for nine commercially important traits in the Portuguese oyster (Crassostrea angulata) using DArT-Seq technology prediction accuracies of genomic selection for nine commercially important traits in the Portuguese oyster (Crassostrea angulata) using. Genes (Basel). 12, 210 (2021).
Zenger, K. R. et al. Genomic selection in aquaculture: Application, limitations and opportunities with special reference to marine shrimp and pearl oysters. Frontiers in Genetics vol. 10 Preprint at (2019). https://doi.org/10.3389/fgene.2018.00693
Coon, S. L., Bonar, D. B. & Weiner, R. M. Chemical production of cultchless oyster Spat using epinephrine and norepinephrine. Aquaculture 58, 255–262 (1986).
Xu, F., Deng, S., Gavriouchkina, D. & Zhang, G. Transcriptional regulation analysis reveals the complexity of metamorphosis in the Pacific oyster (Crassostrea gigas). Mar. Life Sci. Technol. 5, 467–477 (2023).
Suplicy, F. M. & de Souza, R. V. Farming Pacific oysters using the spat-on-shell system Ia shallow area in the subtropical Coast of Brazil. Ocean Coastal. Research 70, (2022).
Hughes-Games, W. L. GROWING THE JAPANESE OYSTER (CRASSOSTREA GZGAS) IN SUB TROPICAL SEAWATER FISH PONDS. I. GROWTH RATE, SURVIVAL AND QUALITY INDEX. Aquaculture vol. 11 (1977).
Lawrence, D. R. & Scott, G. I. The determination and use of condition index of oysters. Estuaries 5, 23–27 (1982).
Ky, C. L., Lo, C. & Planes, S. Mono- and polychromatic inner shell phenotype diversity in pinctada margaritifera donor Pearl oysters and its relation with cultured Pearl colour. Aquaculture 468, 199–205 (2017).
Hoang, T. H. et al. Colour change of Greenlip abalone (Haliotis laevigata Donovan) fed formulated diets containing graded levels of dried macroalgae meal. Aquaculture 468, 278–285 (2017).
Cruz-Romero, M., Kerry, J. & Kelly, A. Fatty acids, volatile compounds and colour changes in high-pressure-treated oysters (Crassostrea gigas). Innovative Food Sci. Emerg. Technol. https://doi.org/10.1016/J.IFSET.2007.05.003 (2008).
Williams, S. T. et al. Identification of shell colour pigments in marine snails clanculus Pharaonius and C. margaritarius (Trochoidea; gastropoda). PLoS One 11, (2016).
Acknowledgements
The authors express sincere gratitude to Jose Garcia Lafuente, Ness Delpero, Rachel Breslin, Eleanor Spencer, Adam Yeap, and Richard Takyi for supporting the fieldwork, sample processing, or image processing. Special recognition is given to Matt Cunningham, Dr. Peter Kube, Dr. John Wright, Nick Griggs, Ian Duthie, Lewa Pertl, and Henry Hewish for their invaluable input at various stages. We are indebted to Josh Poke of Tasmanian Oysters Co. and Joe Jacobson of Little Swanport Oysters for hosting the oyster aquaculture experiments and providing logistical and staff support.
Funding
This study was supported by a University of Tasmania College of Science and Engineering Tasmanian Graduate Research Scholarship, an Australian Institute for Nuclear Science and Engineering Residential Student Scholarship, and an Australian Seafood Industries’ operational support funding.
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E.O.C. designed the study, developed the methods, collected and analysed the performance and quantitative genetics data, wrote the initial draft manuscript, K.L.V. validated and contributed to quantitative genetics, G.G.S., S.A.R., D.M., A.J.T. designed the study, and contributed to the methods development. All authors reviewed and approved the manuscript.
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Chuku, E.O., Verbyla, K.L., Smith, G.G. et al. Genetic and phenotypic insights into shell integrity and market traits in farmed Pacific oysters.
Sci Rep (2025). https://doi.org/10.1038/s41598-025-34267-x
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DOI: https://doi.org/10.1038/s41598-025-34267-x
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