Pinctada Margaritifera Research Articles

Formation of the Outer Shell Layer in Pinctada margaritifera: Structural and Biochemical Evidence for a Sequential Development of the Calcite Units

Calcite prismatic units that form the outer layers of “nacro-prismatic” Pelecypod shells are often used as biomineralization models due to their individual size, simple shape, and spatial arrangement. However, these models do not take into account the developmental history of the shell. After metamorphosis, a series of structural changes predating production of the prisms is commonly missing. Consequently, this study focuses on the early stages of the calcite biomineralization area of the Pinctada margaritifera as it occurs in the outer mantle groove. It also includes the structural changes following the typical “simple prism” status. The interpretation takes advantage of an ancient result from genomic investigations: the localisation of Prisilkin-39, a protein associated with production of the calcite units. A revision of the initial interpretation concerning the position of this Prisilkin-39-producing area provides additional evidence of the role of two distinct mineralizing sectors in the formation of the calcite units in the Pinctada shell: the outer mantle groove and the anterior mineralizing area of the shell mantle.

Pearl shape classification using deep convolutional neural networks from Tahitian pearl rotation in Pinctada margaritifera

Tahitian pearls, artificially cultivated from the black-lipped pearl oyster Pinctada margaritifera, are renowned for their unique color and large size, making the pearl industry vital for the French Polynesian economy. Understanding the mechanisms of pearl formation is essential for enabling quality and sustainable production. In this paper, we explore the process of pearl formation by studying pearl rotation. Here we show, using a deep convolutional neural network, a direct link between the rotation of the pearl during its formation in the oyster and its final shape. We propose a new method for non-invasive pearl monitoring and a model for predicting the final shape of the pearl from rotation data with 81.9% accuracy. These novel resources provide a fresh perspective to study and enhance our comprehension of the overall mechanism of pearl formation, with potential long-term applications for improving pearl production and quality control in the industry.

Characterization and distribution of polybrominated diphenyl ethers in shellfish in Shenzhen coastal waters and assessment of human health risks

This study aims to investigate the profiles of polybrominated diphenyl ethers (PBDEs) in shellfish obtained from Shenzhen coastal waters and assess the potential health risks. We analyzed 74 shellfish samples from eight different species for PBDEs (BDE-28, −47, −99, −100, −153, −154, −183, −209). The concentrations of total PBDEs in different shellfish species ranged from 2.02 to 360.17 pg g−1 wet weight, with the highest levels found in Pectinidae, Babylonia areolate, Ostreidae, Perna viridis, Haliotis diversicolor, Corbiculidae, Pinctada margaritifera, and Veneridae in descending order. Among the PBDE congeners analyzed, BDE-47 was the most abundant, followed by BDE-154 and BDE-153. Furthermore, the estimated daily intake of PBDEs through shellfish consumption for Shenzhen residents were between 0.11 and 0.19 ng kg−1(bw) day−1. To our knowledge, this is the first study to systematically investigate the profiles of PBDEs in eight different shellfish species from Shenzhen's coastal waters and evaluate the potential human health risks associated with shellfish consumption.

Reproductive condition of the black-lip pearl oyster Pinctada margaritifera during the lunar phase.

This study analyzed the relationship between the lunar phase and the reproductive cycle of Pinctada margaritifera inhabiting Weno Island, Chuuk Lagoon, Micronesia. We measured indicators of maturity (gonadosomatic index [GSI]and sexual maturation-related genes) and investigated changes in the gonadal maturity stages (GMS) of P. margaritifera over lunar cycle. GSI was higher around the full moon. GMS of P. margaritifera were classified as the early gametogenesis stage, ripe and spawning stage, and spent and degenerating stage. A large percentage of oysters was observed in the ripe and spawning stage at the first quarter moon in female and the full moon in male as well as in the spent and degenerating stages at the third quarter moon in both sexes. In addition, the expression of doublesex- and mab-3-related transcription factor 2 (DMRT2) in the male P. margaritifera black-lip pearl oyster was the highest during the full and third quarter moon phases, whereas no difference in expression was observed with the lunar phase in females. In contrast, the expression of vitellogenin (VTG) was the highest in female P. margaritifera during the first and third quarters. No difference in expression was observed according to the lunar phase in males. The results suggest that the lunar phase directly affects the expression of sexually mature gonads in P. margaritifera black-lip pearl oyster.

Structure of an amorphous calcium carbonate phase involved in the formation of Pinctada margaritifera shells.

Some mollusc shells are formed from an amorphous calcium carbonate (ACC) compound, which further transforms into a crystalline material. The transformation mechanism is not fully understood but is however crucial to develop bioinspired synthetic biomineralization strategies or accurate marine biomineral proxies for geoscience. The difficulty arises from the simultaneous presence of crystalline and amorphous compounds in the shell, which complicates the selective experimental characterization of the amorphous fraction. Here, we use nanobeam X-ray total scattering together with an approach to separate crystalline and amorphous scattering contributions to obtain the spatially resolved atomic pair distribution function (PDF). We resolve three distinct amorphous calcium carbonate compounds, present in the shell of Pinctada margaritifera and attributed to: interprismatic periostracum, young mineralizing units, and mature mineralizing units. From this, we extract accurate bond parameters by reverse Monte Carlo (RMC) modeling of the PDF. This shows that the three amorphous compounds differ mostly in their Ca-O nearest-neighbor atom pair distance. Further characterization with conventional spectroscopic techniques unveils the presence of Mg in the shell and shows Mg-calcite in the final, crystallized shell. In line with recent literature, we propose that the amorphous-to-crystal transition is mediated by the presence of Mg. The transition occurs through the decomposition of the initial Mg-rich precursor into a second Mg-poor ACC compound before forming a crystal.

Sub-micrometric spatial distribution of amorphous and crystalline carbonates in biogenic crystals using coherent Raman microscopy

In living organisms, calcium carbonate biomineralization combines complex bio-controlled physical and chemical processes to produce crystalline hierarchical hard tissues (usually calcite or aragonite) typically from an amorphous precursor phase. Understanding the nature of the successive transient amorphous phases potentially involved in the amorphous-to-crystalline transition requires characterization tools, which are able to provide a spatial and spectroscopic analysis of the biomineral structure. In this work, we present a highly sensitive coherent Raman microscopy approach, which allows one to image molecular bond concentrations in post mortem shells and living animals, by exploiting the vibrational signature of the different carbonates compounds. To this end, we target the ν1 calcium carbonate vibration mode and produce spatially and spectroscopically resolved images of the shell border of a mollusk shell, the Pinctada margaritifera pearl oyster. A novel approach is further presented to efficiently compare the amount of amorphous carbonate with respect to its crystalline counterpart. Finally, the whole microscopy method is used to image in vivo the shell border and demonstrate the feasibility and the reproducibility of the technique. These findings open chemical imaging perspectives for the study of biogenic and bio-inspired crystals.

Cryogrinding and sieving techniques as challenges towards producing controlled size range microplastics for relevant ecotoxicological tests

The impact of microplastics (MP) has attracted much attention from the scientific community and many laboratory assessments have been made of their effects on aquatic organisms. To produce MP from real environmental plastic waste, which would enable more realistic experiments, we used plastic pearl farming equipment from French Polynesian lagoons. Here, the pearl oyster Pinctada margaritifera could encounter MP coming from their breakdown in its surrounding environment. We tested an established method based on mechanical cryogenic grinding and liquid sieving. Our desired size range was 20–60 μm, corresponding to the optimal particle size ingested by P. margaritifera. The protocol was effective, generating MP particles of 20–60 μm (∼17,000–28,000 MP μg−1), but also produced too many smaller particles. The peak in the desired size range was thus flattened by the many small particles <3 μm (∼82,000–333,000 MP μg−1; 53–70% of total analysed particles), visible at the limit of Coulter counter analysis (cut-off point: 2 μm). Laser diffraction analysis (cut-off point: 0.4 μm) provided greater detail, showing that ∼80–90% of the total analysed particles were <1 μm. Diverging particle size distributions between those expected based on sieving range and those really observed, highlight the need to perform fine-scaled particle size distribution analyses to avoid underestimating the number of small micro- and nanoplastics (MNP) and to obtain an exact estimation of the fractions produced. Size and microstructure characterization by scanning electron microscopy suggested spontaneous particle self-assembly into crystal superstructures, which is the supposed cause of the divergence we observed. Overall, our results emphasize that particle self-assembly is a technical hurdle requiring further work and highlight the specific need to finely characterize the size distribution of MNP used in ecotoxicological experiments to avoid overestimating effects.

Improved ocean-based nursery culture of blacklip pearl oyster (Pinctada margaritifera) juveniles in mesh baskets using cyanoacrylate adhesive

The blacklip pearl oyster, Pinctada margaritifera, supports well-established cultured pearl industries throughout the Pacific with various nursery culture methods used to on-grow juvenile oysters to a size suitable for pearl production. Locally-available plastic baskets are commonly used to rear juvenile oysters, but they do not prevent oysters from aggregating, which negatively impacts production. To develop an understanding of how basket-based nursery culture might best be adapted for rearing juvenile P. margaritifera, this study examined growth and survival of juveniles of varying sizes and stocked at varying densities in mesh baskets when using a cyanoacrylate adhesive to prevent aggregation. During a 3.5-month ocean-based nursery culture period, stocking density was shown to have a significant effect on growth (F = 11.53, p < 0.001), yet a minimal influence on oyster survival (χ2 = 5.05, p = 0.28). By contrast, stocking size influenced survival (χ2 = 7.17, p = 0.03), but had minimal impact on growth (F = 3.24, p = 0.08). Given that mean ( ± SD) survival of juveniles ranged from 65.0 ± 14.4% to 94.0 ± 8.2% and dorsoventral shell growth ranged from 13.9 ± 6.2 mm to 19.7 ± 6.3 mm, depending on stocking density and stocking size, these factors clearly merit consideration before fixing juvenile oysters to baskets with an adhesive. Such results broaden our knowledge of nursery culture methods for P. margaritifera and improve options for small-scale pearl farmers in the Pacific.

Natural stocks of Pinctada margaritifera pearl oysters in Tuamotu and Gambier lagoons: New assessments, temporal evolutions, and consequences for the French Polynesia pearl farming industry.

Knowledge of the status of the black-lipped pearl oyster Pinctada margaritifera populations is critical for the sustainability of the French Polynesia black pearl farming industry. Indeed, this activity relies on collection of spat settling out of the water column, which is inherently related to the abundance of in situ benthic stocks and their reproductive capacities. From surveys performed between 2016 and 2021, we present new stock assessments of natural wild oyster populations from four contrasted pearl farming lagoons (Gambier, Takapoto, Raroia, Takume). Also using Ahe atoll historical data, we first highlight how results vary with the methods (Direct, Zonal and Cokriging) used to scale in situ density measurements to lagoon-scale stocks. Takapoto and Gambier populations were also previously surveyed at least twice since the 1980s, allowing to demonstrate with field data clear changes in stock distributions and population structures. The consequences of our findings are discussed to provide recommendations for stock monitoring and management in the future.

Identifying genes associated with genetic control of color polymorphism in the pearl oyster Pinctada margaritifera var. cumingii (Linnaeus 1758) using a comparative whole genome pool-sequencing approach.

For hundreds of years, the color diversity of Mollusca shells has been a topic of interest for humanity. However, the genetic control underlying color expression is still poorly understood in mollusks. The pearl oyster Pinctada margaritifera is increasingly becoming a biological model to study this process due to its ability to produce a large range of colors. Previous breeding experiments demonstrated that color phenotypes were partly under genetic control, and while a few genes were found in comparative transcriptomics and epigenetic experiments, genetic variants associated with the phenotypes have not yet been investigated. Here, we used a pooled-sequencing approach on 172 individuals to investigate color-associated variants on three color phenotypes of economic interest for pearl farming, in three wild and one hatchery populations. While our results uncovered SNPs targeting pigment-related genes already identified in previous studies, such as PBGD, tyrosinases, GST, or FECH, we also identified new color-related genes occurring in the same pathways, like CYP4F8, CYP3A4, and CYP2R1. Moreover, we identified new genes involved in novel pathways unknown to be involved in shell coloration for P.margaritifera, like the carotenoid pathway, BCO1. These findings are essential to possibly implement future breeding programs focused on individual selection for specific color production in pearl oysters and improve the footprint of perliculture on the Polynesian lagoon by producing less but with a better quality.

Optimizing community-based pearl oyster (Pinctada margaritifera) spat collection strategies in the Fiji Islands

Fiji’s cultured pearl sector relies on wild collected oysters (Pinctada margaritifera) for culture stock. Most oysters are collected by community-based spat collection enterprises but there is little information on the optimal duration of spat collector deployment, which potentially affects oyster yield, oyster size, and the sales value of resulting oysters. We investigated the influence of the timing and duration of spat collector deployment on these parameters, and the potential for early removal of juveniles from spat collectors for intermediate culture. Spat collectors deployed in October and January, during Fiji’s warmer summer season, generated higher numbers of oysters than those deployed in the cooler winter season. The average numbers of spat harvested from spat collectors deployed for 6-month, 8-month, and 14-month periods were 0.6, 1.8, and 1.7 spat per collector, respectively. Shorter spat collector deployment duration of 8-months generated similar numbers of oysters to those of 14-months; however, oysters harvested after 8-months were smaller (20.4 ± 1.8 g) than those harvested after 14-months (89.2 ± 3.2 g). Harvested oysters grown in panel nets during intermediate culture increased significantly in size and weight with 100 % survival. However, oysters removed from spat collectors after 8-months and grown in panel nets for a further 6-months were smaller than those retained on spat collectors for the same 14-month period. Results indicate that, of the options tested, the most profitable for pearl oyster spat collection in Fiji is to harvest spat collectors after 14-months then grow oysters in panel nets for a further 6-months. This assessment is based on production estimates only and detailed cost-benefit analysis is recommended to account for the additional equipment costs and labour inputs required after spat collector harvest. Improved oyster production, using spat collectors only, should deploy collectors during Fiji’s warmer summer season for a 14-month duration.

Insights from tyrosinase into the impacts of modified morphology of calcium carbonate on the nacre formation of pearl oysters

Tyrosinase is a type-3 copper protein with six conserved histidine residues within the copper-binding sites. It participates in mollusk nacre formation. Here, we identified nacreous-layer-specific tyrosinases (NLSTyr) from Pinctada fucata martensii (PmTyr-4 and PmTyr-6), as well as their homologs in Pinctada maxima (PmaxTyr and PmaxTyr4) and Pinctada margaritifera (PmarTyr and PmarTyr-4), which encoded tyrosinases without the six conserved histidine residues within the copper-binding sites. PmTyr-4 and PmTyr-6 mRNAs were spatially concentrated in the mantle central and pearl sac, which are the organs responsible for nacre formation. During shell regeneration and pearl formation, PmTyr-4 and PmTyr-6 were also significantly highly expressed in the mantle and pearl sac. RNA interference showed that PmTyr-4 participated in nacreous-layer formation. The recombinant protein of PmTyr-4 (rPmTyr-4) inhibited the calcium carbonate precipitation rate. Correspondingly, calcium carbonate crystallization assay showed that the aragonite crystals of the rPmTyr-4 group were smaller than those of the control group. Moreover, the calcite and aragonite morphologies of the rPmTyr-4 group were modified compared with the control group. These results suggested that NLSTyr in pearl oyster inhibited calcium carbonate precipitation and affected crystal morphologies during nacre formation. Our findings provided new insights into the evolution and function gain of tyrosinase in Mollusk.

Remote sensing provides new insights on phytoplankton biomass dynamics and black pearl oyster life-history traits in a Pacific Ocean deep atoll

Thus far, no long-term in situ observation of planktonic biomass have been undertaken to optimize the black-lip pearl oyster aquaculture in the remote Tuamotu atolls. The feasibility of using data from the OLI sensor onboard Landsat-8 satellite to determine chlorophyll a concentrations (Chla) in a deep atoll, Ahe, was then assessed over the 2013–2021 period using 153 images. Validations with in situ observations were satisfactory, while seasonal and spatial patterns in Chla were evidenced within the lagoon. Then, a bioenergetic modelling exercise was undertaken to estimate oyster life-history traits when exposed to the retrieved Chla. The outputs provide spatio-temporal variations in pelagic larval duration (11.1 to 30.6 days), time to reach commercial size (18.8 to 45.3 months) and reproductive outputs (0.5 to 1.7 event year−1). This first study shows the potential of using remote sensing to monitor the trophic status of deep pearl farming lagoons and help aquaculture management.

Growth and Survival of Black-lip Pearl Oyster Pinctada margaritifera (Linnaeus, 1758) in Bamboo and Metal-framed Pocket Net Baskets Subjected to Cleaning and Without Cleaning Conditions

The farming of black-lip pearl oyster Pinctada margaritifera (Linnaeus, 1758) has been a viable industry for small and large-scale farmers in the South Pacific, but not in the Philippines, where it is monopolized by large-scale farms primarily based on the gold-lip pearl oyster Pinctada maxima. To promote the industry among small-scale players, we simplified the culture method by using bamboo slats as frame materials and compared them to the common material used in pearl oyster culture, metal rods. A total of 400 individuals seven-month-old hatchery-produced P. margaritifera were used as experimental animals, distributed in the following treatments with five replications: T1 (metal-framed pocket net basket with monthly cleaning), T2 (metal-framed pocket net basket without monthly cleaning), T3 (bamboo-framed pocket net basket with monthly cleaning), and T4 (bamboo-framed pocket net basket without monthly cleaning). Growth was fast in the first four months and slowed down after that. Two-way analysis of variance found no significant differences between the average anteroposterior shell (APS) length increments of pearl oysters between two types of frame, and between two cleaning conditions. Survival rates did not significantly differ between types of basket frame, and between cleaning conditions. Parameters of the “Typical” von Bertalanffy growth model (L∞ = 118.41 mm, K = 1.03 year-1, and t0 = 0.12) suggested that oyster would take about 23.16 months to reach 100 mm APS length, a size suitable for nucleus implantation. The life span of bamboo slats as basket frame was half of the metal frame, and the absence of cleaning has reduced the operational cost by up to 82.08%.

Shell colors and microstructures of four pearl oyster species in the South China Sea

Wild marine pearl oyster shells have rich colors, and the color and gloss of pearls cultivated by pearl oysters are closely related to the pearl layer color of the mantle. Therefore, in this study, four important wild marine pearl oyster species (Pinctada maxima, Pteria penguin, Pinctada margaritifera, and Pinctada fucata) were collected from the South China Sea, and a colorimeter was used to measure the color of their inner and outer shells. We analyzed the color range of their shells and the correlation between the color parameters; additionally, we observed the microstructure of their shells using a scanning electron microscope. The results showed that the color distribution and brightness of the inner shells of the four species were wider than that of the outer shells. In addition, the color distribution range of the outer and inner shells of the four pearl oyster species were P. fucata > P. margaritifera > P. maxima > Pt. penguin and Pt. penguin > P. fucata > P. margaritifera > P. maxima, respectively. Concerning the microstructures of the four pearl oysters, the shell structures of P. maxima, P. margaritifera and P. fucata had a honeycomb arrangement, whereas Pt. penguin had an irregular polygon structure. The P. maxima and P. margaritifera with a strong nacre secretion ability that area and thickness of the single crystal particles were larger than those of Pt. penguin and P. fucata.

Gene expression plasticity, genetic variation and fatty acid remodelling in divergent populations of a tropical bivalve species.

Ocean warming challenges marine organisms' resilience, especially for species experiencing temperatures close to their upper thermal limits. A potential increase in thermal tolerance might significantly reduce the risk of population decline, which is intrinsically linked to variability in local habitat temperatures. Our goal was to assess the plastic and genetic potential of response to elevated temperatures in a tropical bivalve model, Pinctada margaritifera. We benefit from two ecotypes for which local environmental conditions are characterized by either large diurnal variations in the tide pools (Marquesas archipelago) or low mean temperature with stable to moderate seasonal variations (Gambier archipelago). We explored the physiological basis of individual responses to elevated temperature, genetic divergence as well as plasticity and acclimation by combining lipidomic and transcriptomic approaches. We show that P. margaritifera has certain capacities to adjust to long-term elevated temperatures that was thus far largely underestimated. Genetic variation across populations overlaps with gene expression and involves the mitochondrial respiration machinery, a central physiological process that contributes to species thermal sensitivity and their distribution ranges. Our results present evidence for acclimation potential in P. margaritifera and urge for longer term studies to assess populations resilience in the face of climate change.

Arsenic speciation in shellfish from South China Sea: Levels, estimated daily intake and health risk assessment

The purposes of this study were to measure the concentrations of arsenic speciation in shellfish from South China Sea and evaluate the health risk by local residents through shellfish consumption. The median concentrations (in wet weight) of arsenic speciation in shellfish samples were in the following order: AsB (16.0 mg·kg−1) > DMA (1.30 mg·kg−1) > AsV (0.23 mg·kg−1) > AsC (0.08 mg·kg−1) > AsIII (0.05 mg·kg−1) > MMA (0.01 mg·kg−1). Among shellfish species, Mactra mera and Babylonia areolata were found to accumulate iAs and AsB, respectively. The target hazard quotient values of iAs (THQiAs) in all shellfish samples were lower than 1. However, the carcinogenic risk values of iAs (CRiAs) in the Mactra mera, Mytilus galloprovincialis and Pinctada margaritifera were beyond the acceptable range, implying that continuous exposure to iAs pollution via the consumption of these shellfish would pose a potential cancer risk to local consumers.

Amorphous-to-crystal transition in the layer-by-layer growth of bivalve shell prisms

Biomineralization integrates complex physical and chemical processes bio-controlled by the living organisms through ionic concentration regulation and organic molecules production. It allows tuning the structural, optical and mechanical properties of hard tissues during ambient-condition crystallisation, motivating a deeper understanding of the underlying processes. By combining state-of-the-art optical and X-ray microscopy methods, we investigated early-mineralized calcareous units from two bivalve species, Pinctada margaritifera and Pinna nobilis, revealing chemical and crystallographic structural insights. In these calcite units, we observed ring-like structural features correlated with a lack of calcite and an increase of amorphous calcium carbonate and proteins contents. The rings also correspond to a larger crystalline disorder and a larger strain level. Based on these observations, we propose a temporal biomineralization cycle, initiated by the production of an amorphous precursor layer, which further crystallizes with a transition front progressing radially from the unit centre, while the organics are expelled towards the prism edge. Simultaneously, along the shell thickness, the growth occurs following a layer-by-layer mode. These findings open biomimetic perspectives for the design of refined crystalline materials. Statement of significanceCalcareous biominerals are amongst the most present forms of biominerals. They exhibit astonishing structural, optical and mechanical properties while being formed at ambient synthesis conditions from ubiquitous ions, motivating the deep understanding of biomineralization. Here, we unveil the first formation steps involved in the biomineralization cycle of prismatic units of two bivalve species by applying a new multi-modal non-destructive characterization approach, sensitive to chemical and crystalline properties. The observations of structural features in mineralized units of different ages allowed the derivation of a temporal sequence for prism biomineralization, involving an amorphous precursor, a radial crystallisation front and a layer-by-layer sequence. Beyond these chemical and physical findings, the herein introduced multi-modal approach is highly relevant to other biominerals and bio-inspired studies.

GROWTH PATTERNS OF THE PEARL OYSTER Pinctada margaritifera IN NORTH SULAWESI WATERS

The pearl oyster Pinctada margaritifera (Linnaeus, 1758) or black lip pearl oyster is a marinebivalves with important economic value. This Indo-Pacific species is found in abundance in the waters of North Sulawesi, but cultivation activities have not been optimized. Growth information is important for aquaculture activities because it is a useful indicator to determine the health of pearl oysters and environmental suitability (Moussa, 2013). The purpose of this study was to determine the growth pattern of P. margaritifera pearl shells in the waters of North Sulawesi. Species P. margaritifera were collected at a depth of 2-20 m in the waters of North Minahasa Bahoi, Arakan waters South Minahasa and Talengen waters Sangihe Islands, North Sulawesi Province. The morphometric parameters observed included shell length (PC), shell height (TC), shell thickness (tC), and total weight (BT). The relationship between length, height, shell thickness and total weight was analyzed by regression equation. Morphometric measurements of P. margaritifera showed average shell length (PC) of 95.26 mm (Arakan waters), 81.15 mm (Talengen waters) and 70.19 mm (Bahoi waters). The growth pattern of P. margaritifera in the waters of Bahoi, Arakan and Talengen, North Sulawesi Province was allometric negative. This means that the increase in length, height and thickness of the shell is faster than the total weight.

Challenges and opportunities of aquaculture supply chains: Case study of oysters in Australia

Assessing seafood supply chains is important at both individual business and industry levels to ensure profitability, efficiency, and consumer satisfaction. Such assessments are typically aimed at understanding the structure of the supply network and at optimizing processes within the chain. Yet, identifying broader supply chain challenges (e.g., access to inputs, market access barriers) and opportunities (e.g., increasing demand) at an industry level is also important to inform industry development strategies. The aim of this case study is to identify challenges and opportunities within the four oyster species’ supply chains in Australia (Sydney rock oyster - Saccostrea glomerata, the Pacific oyster - Crassostrea gigas (also referred to as Magallana gigas), Angasi oyster - Ostrea angasi, Black lip oyster - Saccostrea echinate/Striostrea (Parastriostrea) mytiloides) and to offer options on how to address these. Data was collected through supply chain stakeholder interviews during October 2019 and August 2020. Findings suggest that challenges vary depending on the production scale of the industries as low-volume producing oyster industries grapple with production related challenges, while challenges of large-volume producing oyster industries also center around value creation. Opportunities are predominantly seen in addressing the identified challenges.