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Introduction: Fluctuations in water quality characteristics influence the productivity of blue crabs (Callinectes sapidus), and the risk of human exposure to pathogenic Vibrio species. Thus, this study assessed the prevalence of total and pathogenic/clinical markers of Vibrio parahaemolyticus and Vibrio vulnificus in blue crabs and seawater from the Maryland Coastal Bays (MCBs) and the correlation between Vibrio levels and physicochemical parameters. Methods: Three to five crabs and 1 L of seawater were collected monthly for 3 years (May 2018 to December 2020) from six sites within the MCBs. Hemolymph and crab tissue were extracted and pooled for each site. Extracted hemolymph, crab tissue, and seawater were analyzed for V. parahaemolyticus and V. vulnificus using the Most Probable Number (MPN) and real-time PCR methods. A one-way Analysis of Variance (ANOVA), correlations, and linear models were used to analyze the data. Akaike Information Criterion (AICc) was evaluated to determine the model that provides the best fit to the data relating to Vibrio concentrations and environmental factors. Results: Results suggested that environmental factors could influence the growth of Vibrio spp. Both V. parahaemolyticus and V. vulnificus were more prevalent during the warmer months than colder months. Vibrio was more prevalent in crab samples compared to seawater. Vibrio vulnificus concentrations in seawater and hemolymph were positively correlated with temperature (p = 0.0143 seawater) and pH (p = 0.006 hemolymph). A negative correlation was observed between the concentration of V. vulnificus in whole crab (tissue) and dissolved oxygen level (p = 0.0256). The concentration of V. parahaemolyticus in seawater was positively correlated with temperature (p = 0.009) and negatively correlated with dissolved oxygen (p = 0.012). Discussion: These results provide current information on the spatial and temporal distributions of Vibrio spp. in the MCBs that are useful for implementing more efficient processing and handling procedures of seafood products. [ABSTRACT FROM AUTHOR]

Introduction: The recent and growing bio-invasion of the Callinectes sapidus (known as blue crab) is causing damages in the European aquatic ecosystems, and affecting the livelihoods of the fishermen. In this context, this study explores the socio-economic impacts of this bio-invasion on small-scale artisanal fishermen in the Apulia (southern Italy) and Algarve (southern Portugal) regions, analyzing their perceptions and highlighting the repercussions of this bioinvasion on their livelihoods. Methods: For this purpose, we carried out a field survey with representative small-scale artisanal fishermen based on the "Socio-economic Impact Classification of Alien Taxa" (SEICAT) approach by means of an "Exploratory Factor Analysis" (EFA), and a "Hierarchical Analysis and K-means Cluster Analysis". Results and discussion: The findings reveal that the two study areas, Apulia and Algarve, exhibit markedly different perceptions of the impact of the blue crab invasion on the well-being and activity of fishermen. In Apulia, the invasion has led to extensive damage to fishing nets, physical harm, a decline in other commercial species, reduced catch quantities, increased working hours, higher costs, and lower incomes. Conversely, in the Algarve, while net damage is less severe, the primary concerns are physical harm, increased working hours, higher costs, and reduced income. Consequently, this research provides an empirical basis for the adoption of management measures and interventions to mitigate the socioeconomic impacts of the blue crab on the fishing community and local economy, thereby contributing to the well-being of both individuals and the marine ecosystem. [ABSTRACT FROM AUTHOR]

The Atlantic blue crab, Callinectes sapidus, is acknowledged as one of the worst invasive alien species in the Mediterranean, impacting biodiversity and human activities. Native to the western Atlantic, it has expanded to European coastal waters since the early 1900s. Despite its ecological and commercial importance, genetic research on this species is limited. Here we show a comprehensive investigation of the genetic variation and evolutionary history in Callinectes sapidus using 667 mitochondrial COI gene sequences. Our dataset encompasses 36 newly generated sequences from previously understudied Mediterranean sites and 631 from worldwide locations obtained from the GenBank public database. Our findings reveal two distinct, but closely related, genetic groups within the species' distribution range, suggesting the occurrence of a potential species complex. Furthermore, in the Mediterranean, low levels of genetic variability were observed except for substantial haplotypic differentiation in Turkish samples. This study depicts the global genetic diversity and evolutionary patterns of Callinectes sapidus, offering new insights into the taxonomic status of the species. [ABSTRACT FROM AUTHOR]

Understanding nutrition and its effect on growth is essential for developing diets in commercially important species. This study aimed to evaluate the larval development of Callinectes sapidus fed with rotifers (Brachionus plicatilis) enriched with Chlorella pyrenoidosa (Ch) as a main protein source and a lipid emulsion (Spr) rich in highly unsaturated fatty acids. The enriched compositions had seven ratios Ch/Spr (w/w): 100/0, 90/10, 80/20, 70/30, 60/40, 50/50, and 40/60. The enriched rotifers with each ratio were called diets. Lipids increased progressively between 100/0 and 40/60 (7.48 to 11.30 g 100 g-1), as well as energy (21.88 to 23.16 kJ g-1), but the protein level did not show a clear trend (63.93 and 67.50 g 100 g-1). The production response of blue crab larvae showed significant differences within diets (P < 0.05). The highest survival (29 to 34%) was obtained in the 50/50 and 40/60 treatments. In the 40/60, 50/50, and 60/40 diets, the larval cycle was shorter (P < 0.05), and the megalopa stage was reached between 49 and 52 days of culture. Metamorphosis tomegalopa occurred between the fifth and eighthmolts; its corresponding weight varied from 0.72 to 1.33 mg, the length varied from 2,632 to 2,926 μm, and Le Cren's condition factor varied from 0.83 to 1.16. The most important factor in the production response was the diet lipid content, which was significantly correlated with the survival, weight, length, and condition factor of C. sapidus larvae. Findings of the present study can be applied in future efforts towardsmass culture of blue crab larvae in the Caribbean and can also potentially be used to study other crustacean species with similar characteristics. [ABSTRACT FROM AUTHOR]

Bone tissue engineering (BTE) provides an alternative for addressing bone defects by integrating cells, a scaffold, and bioactive growth factors to stimulate tissue regeneration and repair, resulting in effective bioengineered tissue. This study focuses on repurposing chitosan from blue swimming crab (Portunus pelagicus) shell waste as a composite scaffold combined with HAP and COL I to improve biocompatibility, porosity, swelling, and mechanical properties. The composite scaffold demonstrated nearly 60% porosity with diameters ranging from 100–200 μm with an interconnected network that structurally mimics the extracellular matrix. The swelling ratio of the scaffold was measured at 208.43 ± 14.05%, 248.93 ± 4.32%, 280.01 ± 1.26%, 305.44 ± 20.71%, and 310.03 ± 17.94% at 1, 3, 6, 12, and 24 h, respectively. Thus, the Portunus pelagicus scaffold showed significantly lower degradation ratios of 5.64 ± 1.89%, 14.34 ± 8.59%, 19.57 ± 14.23%, and 29.13 ± 9.87% for 1 to 4 weeks, respectively. The scaffold supports osteoblast attachment and proliferation for 7 days. Waste from Portunus pelagicus shells has emerged as a prospective source of chitosan with potential application in tissue engineering. [ABSTRACT FROM AUTHOR]

Since 2014, the provision of the aquatic ecosystem services has been gradually affected due to the biological invasion of Callinectes sapidus (Rathbun, 1896, Crustacea, Decapoda, Portunidae), commonly known as Atlantic blue crab, across several lagoon-like locations in Italy. In addition, this serious aquatic invasive species, native of North American coasts, has already inflicted economic damage of about EUR 100 million to the Italian fishing and farming communities over the past year. To counter their severe and rapid spread, the Italian Government has encouraged the fishing communities to catch as many as possible and commercially exploit them for human consumption in an attempt to manage their expansion. Since there is an ongoing promotion for the consumption of blue crab by forging novel food businesses in Italy, this paper aims to predict the public preferences and their willingness to pay (WTP) towards this biological invader. For this purpose, a discrete choice experiment approach is used, by means of a multinomial logit model (MNL) and latent class model (LCM). The social field survey involves a representative sample of 440 valid respondents in Apulia Region, southern Italy. The descriptive statistics results reveal that 67.50% of the local citizens interviewed know about the blue crab invasion, while 29.09% of them have already consumed this seafood species. In addition, the MNL results show that the most appreciated attributes of the blue crabs by respondents are freshness and large size. Further, the LCM findings reveal two representative classes of Apulian consumers; the first group of citizens (70.9% of total respondents) expresses positive appreciation for consuming blue crabs, while the second group (29.1% of total respondents) is not willing to pay a premium price regarding this potential commercial activity. Furthermore, the econometric results show that the average value that Apulian's (i.e. those belonging to Class/Group I of respondents) WTP for blue crabs' consumption is about EUR 18 per kilogram. In this regard, this research has public and private implications and may reasonably promote the commercial exploitation of blue crabs, enhancing the reduction of its population density through human consumption as a promised management control strategy and forging a novel profitable business mainly for local small-scale artisanal fisheries. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the socio-economic aspects of crab fisheries in Maginti Island, West Muna Regency. Data collection was carried out from March 2021 to December 2023. The data collected were the socio-economic aspects of crab fisheries, including the level of community education, the number of fishermen, income from crab fishing, crab production 2017 - 2023, crab prices during 2017-2023, and the crab trade supply chain. Data were obtained through in-depth interviews with stakeholders, including 62-74 fishermen, three local collectors, and two district-level collectors. Interviews were directly conducted with an open-ended question system based on data needs. Data analysis was carried out with a descriptive-quantitative approach. The study results showed that in the social aspect, crab fishermen's education is dominated by elementary school (S.D.) graduates, namely 61.29% in 2017 and 60.81% in 2023. In the economic aspect, most fishermen have a net income ranging from 1,000,000 - 2,000,000 IDR/month, which was affected by fluctuations in BSC prices. Crab prices from fishermen to collectors tend to fluctuate throughout 2017-2023. The average price of crabs per kg was 32,083.33 IDR in 2017, 36,166.67 IDR in 2018, 30,750 IDR in 2019, 23,750 IDR in 2020, 64,666.67 IDR in 2021, 31,083.33 IDR in 2022, and 44,791.67 IDR in 2023. Price fluctuations occurred since BSC fisheries in Maginti Island are part of the global fisheries supply chain that reaches the international market to America, China, and others. Fluctuations in the global BSC prices not only affected the prices locally but could increase fishermen's income by up to 11.25% which is >2,000,000 IDR/month from 2017-2023. The increase in income indicates that BSC fisheries in Maginti Island have supported the implementation of the sustainable development goals (SDGs), specifically SDGs-1, namely no poverty. [ABSTRACT FROM AUTHOR]

This study aimed to assess the sustainability status of the blue swimming crab fisheries resources in Bone Bay through a rapid assessment approach to the dimensions of sustainable fisheries development. A multidimensional scaling (MDS) approach through the rapfish process was used to assess the sustainability status of the blue swimming crab fisheries. The sustainability analysis was expressed in the sustainability index of fisheries management. The results showed that the sustainability status of the blue swimming crab fishery in Bone Bay was categorized as less sustainable with an average value of 38.43%. The ecological, economic, social, technological and institutional dimensions were categorized as less sustainable. 24 attributes contributed to the sustainability index value (leverage analysis) of the blue swimming crab fisheries management in Bone Bay, which requires an important attention in the sustainability of the blue swimming crab fisheries management. [ABSTRACT FROM AUTHOR]

The invasion of non-native species (NNS) is one of the greatest threats to biodiversity loss and represents a major problem in the Mediterranean Sea. Although many recent EU policies and directives address this problem and numerous scientific papers have been published, the available data remains scattered and incomplete. In 2021, the World Register of Introduced Marine Species (WRiMS), a newly established database, was launched but has not yet undergone systematic analysis. This study performed a thorough examination of the NNS documented in the WRiMS database within the Mediterranean Sea (International Hydrographic Organization Sea Area). Our findings revealed that the majority of species in the WRiMS database for the Mediterranean are classified as "unspecified" or "uncertain", with only 79 species labeled as "invasive" and 13 as "of concern". The number of recorded animal species exceeds that of plants, and most species belong to the phyla Chordata and Mollusca. Callinectes sapidus and Fistularia commersonii were the most frequently recorded species in the WRiMS for the Mediterranean. Although there exists some data on the impact of NNS and the vectors of their introduction, the information remains incomplete and requires further scientific research. The synthesized and summarized data in the supplement can be valuable input for a range of management decisions and for guiding further scientific research concerning NNS invasions in the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

In the past few years, non-native blue crab has been expanding its range in the Adriatic and Mediterranean Seas. However, when non-indigenous species establish a lasting presence in a novel ecosystem and actively expand into other regions, posing potential risks to local biodiversity and economic harm, they are classified as invasive species. For this study, two different batches of blue crabs were collected: one from the Mediterranean Sea and the other from the Adriatic coast area. Considering the negative ecological impact that blue crab has had and continues to have on the Italian coasts, this work was aimed to evaluate the characteristics of the Adriatic Sea "variant"; another goal was to propose the potential use of blue crab as a commercially profitable source due to its organoleptic characteristics. Data obtained revealed a high protein content, a good lipid profile, a low number of plastic particles, and the absence of toxic metals and pathogenic microorganisms. A deep statistical analysis was conducted to compare different portions of blue crab from the Adriatic and Mediterranean Seas. The results suggest that Callinectes sapidus is beneficial for human consumption and represents a valuable seafood, and its carapace could be used as compliant feed for aquaculture due to its metal composition and microbiological content. [ABSTRACT FROM AUTHOR]

Dinoflagellates belonging to the genus Hematodinium are key parasites of marine crustaceans, primarily decapods. In this study, we document the first report of H. perezi Chatton & Poisson, 1930 on the African Atlantic coast. This is also the first parasite record in the invasive non-native Atlantic blue crab Callinectes sapidus Rathbun, 1896 in Morocco. Specimens of C. sapidus were sampled in winter 2023 from two Ramsar sites on the Moroccan Atlantic, namely Merja Zerga and Oualidia Lagoons, and were screened to detect the presence of parasites in their hemolymph. Based on staining fresh hemolymph smears, we did not detect Hematodinium in any of the 36 investigated individuals (20 and 16 from Merja Zerga and Oualidia Lagoons, respectively), probably due to methodological artifacts. The PCR-based method was revealed to be more accurate in diagnosing the Hematodinium parasite. It showed that at Merja Zerga Lagoon, 13 individuals of C. sapidus were infected by the parasite (prevalence: 65%) in comparison to four at Oualidia Lagoon (25%). Genetic analysis, based on the ITS1 rDNA gene from Hematodinium, confirmed the sequences as being those of Hematodinium perezi. [ABSTRACT FROM AUTHOR]

The blue crab, Callinectes sapidus (Rathbun, 1896), has become an invading species in the Mediterranean region, almost completely replacing native species within a few years and causing significant loss to local production. In some areas, there is an urgent need to propose new supply chains based on blue crab exploitation, where the potential valorisation routes for unsaleable blue crab and waste play an important role. The final purpose is to transform a threat into a treasure, towards a more sustainable world. In addition to applications in food industries, the considerable quantity of bioactive compounds in by-products, such as polysaccharides, proteins, amino acids, carotenoids, and chitin, needs to be capitalised by means of efficacious strategies and appropriate management. Crab exoskeleton can also be exploited as a carbonaceous material with applications in several fields, including medicine. Blue crab bioactive molecules have been widely recognised for having antioxidant, anticancer, antidiabetic, anti-inflammatory, and antimicrobial properties. Due to these functional and distinctive activities, such high-value components could be employed in various industries such as food–feed–pharma and cosmetics. Recycling and reusing these underutilised but economically valuable waste or by-products could help to reduce the environmental impacts of the whole supply chain from the perspective of the circular economy. [ABSTRACT FROM AUTHOR]

The latest report from the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) expresses concern over the global proliferation of non-native species (NIS) driven by increasing temperatures. In 2023, the invasive blue crab Portunus segnis in the Mediterranean experienced a significant range expansion due to warmer waters in northern and western regions. Recognizing thermal tolerance as crucial for conservation, this study, using the blue crab as a model, emphasized the importance of considering thermal metabolic performance in conservation efforts. In this study, we experimentally measured the metabolic performance of P. segnis at different temperatures (from 7 to 42°C) using an oxygen consumption measurement system. The thermal performance curve (TPC) of P. segnis rose from 0.016 ± 0.011 mgO2 h−1 gWW−1 (12°C) to 0.238 ± 0.011 mgO2 h−1 gWW−1 (34°C), and decreased beyond. Organisms succumbed at 7°C and 42°C. The TPC obtained was compared with 24 TPC models and the O’Neill regression was the best fitting model determining the minimum critical thresholds (CTmin) at 11.33°C and CTmax at 41.13°C. Using the TPC curve equation, we applied the curve to satellite Mediterranean temperature data for the year 2022 and for the future (RCP 4.5 and 8.5) to determine the current and future monthly distribution of favorable thermal habitats for P. segnis. Results anticipated the future expansion of the species along the Spanish, French, Italian, and Greek coasts of the Aegean Sea, providing maps to prioritize high-risk invasion areas. Additionally, in the areas where the species in currently present, results predicted a long-term persistence of the species. Understanding species' responses to temperature changes appears crucial for anticipating and addressing the impending expansion of invasive species, underscoring the urgency of nature conservation measures.

In the Ebro Delta (Catalonia, Spain), the abundance of burrowing bivalves has dramatically decreased, with the blue crab, Callinectes sapidus, being blamed by shellfish collectors. Trends from 2010 evidence a decrease in the capture of clams (Ruditapes spp.) before 2016 (start of blue crab fisheries), although a further decline in both clams and cockles (Cerastoderma glaucum) occurred in 2018. In contrast, captures of razor clams (Ensis siliqua) have increased by 3.6-fold since 2016. Predation risk for these taxa, with contrasting burrowing capacities (1.7 ± 0.3 cm, 0.4 ± 0.2 cm, and 26.3 ± 0.1 cm, respectively), was assessed using predation preference (N = 5 tanks; 5 individuals of each species) and no-choice experiments (N = 5 tanks; 15 individuals of the same taxa) in the absence and presence of sand. The results showed that, in the absence of sand, razor clams were fully preyed upon in 24 h, clams in 96 h, and cockles reached 60% after 144 h. Conversely, when sand was present, only 4% of razor clams were predated, while clams and cockles reached 60–100% in 120–144 h. The no-choice results featured similar patterns, depending on substrate availability. Overall, clams and cockles appear to be greatly vulnerable to blue crab predation, whereas razor clams may escape thanks to their deeper burrowing capacity. [ABSTRACT FROM AUTHOR]

A total of 1315 individuals were collected from the catches off the Bawasalo waters during March -August 2023. This study aimed to analyze the population parameters and exploitation rate of blue swimming crab (Portunus pelagicus), caught by fishermen using a bubu naga fishing gear in the waters of Bawasalo, Pangkep District, South Sulawesi. The observed parameters included the size distribution of the carapace width, carapace width-weights relationship, age group, growth rate, total mortality rate, natural rate, fishing rate, and exploitation ratio analyzed with the ELEFAN II program. The size of carapace width ranged from 6.70 to 13.80cm, with the highest proportion observed at carapace widths between 9.10 and 9.60cm (19.7%) and the lowest proportion observed at carapace widths between 13.3 and 13.8cm (0.2%). Carapace widths below 10cm accounted for 66.69% of captures, while those above 10cm accounted for 33.31%. The carapace width-weight relationship was computed as W = 0.1038L2.7334 (negative allometric). The von Bertalanffy growth parameters were estimated to be K = 0.41 yr-1, Lmax = 15.10 cm, and t0 = -0.723 yr. The total mortality (Z), natural mortality (M), and fishing mortality (F) were calculated as 2.70, 1.22, and 1.48 yr-1, respectively. The exploitation rate (E = 0.55) suggests that the stock of P. pelagicus was slightly higher than that of an optimally exploited stock. [ABSTRACT FROM AUTHOR]

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The accurate depth imaging of piled products provides essential perception for the automated selection of individual objects that require itemized food processing, such as fish, crabs, or fruit. Traditional depth imaging techniques, such as Time-of-Flight and stereoscopy, lack the necessary depth resolution for imaging small items, such as food commodities. Although structured light methods such as laser triangulation have high depth resolution, they depend on conveyor motion for depth scanning. This manuscript introduces an active dual line-laser scanning system for depth imaging static piled items, such as a pile of crabs on a table, eliminating the need for conveyor motion to generate high-resolution 3D images. This advancement benefits robotic perception for loading individual items from a pile for itemized food processing. Leveraging a unique geometrical configuration and laser redundancy, the dual-laser strategy overcomes occlusions while reconstructing a large field of view (FOV) from a long working distance. We achieved a depth reconstruction MSE of 0.3 mm and an STD of 0.5 mm on a symmetrical pyramid stage. The proposed system demonstrates that laser scanners can produce depth maps of complex items, such as piled Chesapeake Blue Crab and White Button mushrooms. This technology enables 3D perception for automated processing lines and offers broad applicability for quality inspection, sorting, and handling of piled products. [ABSTRACT FROM AUTHOR]

Simple Summary: The Atlantic blue crab Callinectes sapidus, which is native to the western Atlantic coast and listed among the 100 most invasive alien species in the Mediterranean Sea, is attracting a great deal of interest because of its rapid colonisation of new areas, the significant increase in its population, and the impacts it may have on ecosystems. Outside its natural distribution range, the species was first found on the European coasts of the Atlantic in the early 1900s, and a few decades later, it was introduced into the Mediterranean Sea, probably through maritime traffic. Currently, it is found in almost the entire Mediterranean Basin and is also expanding into the Black Sea and along the north African and Iberian Atlantic coasts. This study describes the distribution of the Atlantic blue crab in Northwest Europe, in the Mediterranean Sea, and in adjacent waters through a series of ecological indicators elaborated using spatial–temporal statistics. The main results highlight that the species is expanding in the Mediterranean and adjacent waters, while in northern Europe, the population remains confined in some areas. The main species detection methods are analysed, finding that traps and nets are the most used methods, and management suggestions are provided. The Atlantic blue crab Callinectes sapidus, which is native to the western Atlantic coast and listed among the 100 most invasive alien species in the Mediterranean Sea, is attracting a great deal of interest because of its rapid colonisation of new areas, the significant increase in its population, and the impacts it may have on ecosystems and ecosystem services. Outside its natural distribution range, the species was first found on European Atlantic coasts in the early 1900s and was introduced into the Mediterranean Sea a few decades later, probably through ballast water. Currently, it is found in almost the entire Mediterranean Basin and is also expanding into the Black Sea and along the north African and Iberian Atlantic coasts. Based on a systematic review of C. sapidus occurrences, this study describes its distribution, aggregation patterns, and spatial structure in Northwest Europe, the Mediterranean Sea, and adjacent waters through a series of ecological indicators elaborated using GIS spatial–temporal statistics. The main results highlight that the species is expanding in the Mediterranean and adjacent waters, while in northern Europe, the population remains confined in some areas. Furthermore, the main species detection methods are analysed, finding that traps and nets are the most frequently used methods, and management suggestions are provided. [ABSTRACT FROM AUTHOR]

In the presented work, the effect of hydroxyapatite/polycaprolactone (HAp/PCL) ratio and the immersion/withdrawal speed on the corrosion rate and antibacterial properties of Ti-6Al-4V ELI dental implant coating was investigated. Ti-6Al-4V ELI implants are coated with different HAp-PCL ratios and immersion speeds. The functional groups of product hydroxyapatite were confirmed using the HAp standard JCPDS no. 09-0432, with crystallinity of 88.32% and ratio Ca/P at 2.12. The result shows that the higher concentrations of hydroxyapatite result in the decrease of corrosion rate and increased antibacterial activity reflected in larger inhibition zones. Additionally, the higher immersion and withdrawal speeds during dip-coating lead to lower corrosion rates. Furthermore, decreased corrosion rates may enhance the antibacterial properties of HAp-PCL coatings. These results demonstrate that the HAp/PCL composite can be considered as a prospective candidate for dental implant Ti-6Al-4V ELI coating. [ABSTRACT FROM AUTHOR]

Objective: Recent estimates of the North Carolina blue crab Callinectes sapidus stock found that the stock is overfished and overfishing is occurring. Threats outlined in the 2018 stock assessment include climate change and estrogenic endocrine‐disrupting chemicals (EEDCs). The objective of this study was to use an individual‐based modeling approach to simulate the long‐term effects of climate change and EEDCs on the North Carolina blue crab stock. Methods: To do this, we built an individual‐based model that simulated the life history of individual blue crabs, including but not limited to growth, reproduction, and mortality. We then tested our population of blue crabs against 30 different combinations of temperature and EEDC scenarios over 50 years to determine the long‐term effects on the population. Result: Our simulations suggested that the North Carolina blue crab population may be relatively resilient to climate change‐related temperature shifts but that there may be significant impacts at the population level as summer temperatures become more extreme. Endocrine‐disrupting chemical effects resulted in an alternative stable state of lower catch or the total extinction of the population. Conclusion: These results suggest that management strategy changes may be necessary as temperatures become more extreme in the region. In addition, more research is necessary to fully understand the effects of EEDCs on blue crabs and other crustaceans at the individual and population level. Impact statementThis study used a novel approach to connect fine‐scale blue crab ecology to broadscale population ecology. This model can be a useful predictive tool that allows for assessment of the effects of future threats or regulation changes and can be modified to simulate other important crustacean species. [ABSTRACT FROM AUTHOR]

Bioinvasions constitute both a direct and an indirect threat to ecosystems. Direct threats include pressures on local trophic chains, while indirect threats might take the form of an invasion of a microorganism alongside its host. The marine dinoflagellate Hematodinium perezi, parasitizing blue crabs (Callinectes sapidus), has a worldwide distribution alongside its host. In Greece, fluctuations in the blue crab population are attributed to overexploitation and the effects of climate change. The hypothesis of the present study was that blue crab population reductions cannot only be due to these factors, and that particular pathogens may also be responsible for the fluctuations. To investigate this hypothesis, both lethargic and healthy blue crab specimens were collected from three different fishing sites in order to assess the health status of this important species. Together with the lethargic responses, the hemolymph of the infested crabs presented a milky hue, indicating the first signs of parasitic infestation with H. perezi. The histopathological results and molecular identification demonstrated the effect of the presence of H. perezi in the internal organs and their important role in the mortality of blue crabs. Specifically, H. perezi, in three different tissues examined (heart, gills, hepatopancreas), affected the hemocytes of the species, resulting in alterations in tissue structure. Apart from this dinoflagellate parasite, the epibiotic peritrich ciliate Epistylis sp. was also identified, infecting the gills. This study represents the first detection of H. perezi in the eastern Mediterranean, demonstrating that this is the main causative agent of blue crab mortality on Greek coastlines. [ABSTRACT FROM AUTHOR]

The blue crab (BC) Portunus segnis is considered an invasive species colonizing Tunisian coasts since 2014. This work aims to explore its associated bacteria potential to produce anionic exopolysaccharides (EPSs) in order to open up new ways of valorization. In this study, different BC samples were collected from the coastal area of Sfax, Tunisia. First, bacterial DNA was extracted from seven different fractions (flesh, gills, viscera, carapace scraping water, and three wastewaters from the production plant) and then sequenced using the metabarcoding approach targeting the V3-V4 region of the 16S rDNA to describe their microbiota composition. Metabarcoding data showed that the dominant bacterial genera were mainly Psychrobacter, Vagococcus, and Vibrio. In parallel, plate counting assays were performed on different culture media, and about 250 bacterial strains were isolated and identified by sequencing the 16S rDNA. EPS production by this new bacterial diversity was assessed to identify new compounds of biotechnological interest. The identification of the bacterial strains in the collection confirmed the dominance of Psychrobacter spp. strains. Among them, 43 were identified as EPS producers, as revealed by Stains-all dye in agarose gel electrophoresis. A Buttiauxella strain produced an EPS rich in both neutral sugars including rare sugars such as rhamnose and fucose and uronic acids. This original composition allows us to assume its potential for biotechnological applications and, more particularly, for developing innovative therapeutics. This study highlights bacterial strains associated with BC; they are a new untapped source for discovering innovative bioactive compounds for health and cosmetic applications, such as anionic EPS. [ABSTRACT FROM AUTHOR]

In response to the escalating demand for blue swimming crabs (BSC) and the consequential impact on their habitat and population, this study advocates for sustainable management through a holistic approach. Our comprehensive framework integrates ecological conservation, socioeconomic well-being, and governance principles, aiming to establish a policy framework for the sustainable management of BSC in the Eastern Coast of Lampung. The research emphasizes the urgent issue of overexploitation, with an exploitation rate of 0.71, requiring immediate attention to prevent stock depletion and maintain ecosystem health. Findings reveal that male BSC, measured by carapace width, typically reaches the length at first catch (Lc50) at approximately 118.69mm, while for females, it is about 122.70 mm--indicating that BSC is often caught larger than the 10 cm legal requirement set by the Ministry of Marine and Fisheries of Indonesia. Economic analysis demonstrates the profitability of the blue swimming crab business on Lampung's east coast, with a favorable crab capture per trip (4.63) and total costs ratio (1.18). The study area, featuring an extensive mangrove forest, hosts a crucial crustacean population, contributing significantly to BSC's diet. Beyond ecological significance, mangrove conservation enhances our understanding of environmental sustainability, particularly in carbon stock contributions. Addressing sustainability challenges requires a multi-faceted approach, including precise fishing technologies, effective regulation enforcement, and improved monitoring. Collaborative efforts among government authorities, fishing communities, and conservation groups are essential for balancing economic interests with the longterm ecological health of BSC populations in the study area. [ABSTRACT FROM AUTHOR]

The current invasion of the Mediterranean Sea by the Atlantic blue crab Callinectes sapidus requires the implementation of effective strategies of control and management. In native areas, the species is highly appreciated as a hard- and soft-shell seafood, and hard-shell fisheries are developing in a number of invaded countries. Here, to verify alternative approaches for enhancing the commercial value of the species, we carried out a pilot experiment to test a flow-through system for the production of soft-shell blue crabs. Fifty crabs were collected in the Lesina lagoon (Adriatic Sea, Italy) and inspected for the coloration of the line on the distal edge of the fifth pereiopod. Accordingly, they were grouped into three groups showing no, white, and red lines, symptomatic of the progression of the pre-molt phase, and maintained for 31 days in a flow-through pond system. The overall mortality rate determined during the trial was similar across the three groups and ranged between 10 and 20%, indicating that the flow-through system was effective for rearing the crabs. In addition, the molting rate was 10%, 65%, and 85% for individuals at an early, intermediate, and advanced pre-molt stage, confirming that the line coloration can be used as an effective indicator of the advancement of the molting process. Our study provides the first contribution towards the introduction in the Mediterranean fishery sector of novel procedures and practices for the production of soft-shell blue crabs, which may represent a cost-effective strategy to enhance the capture and commercialization of this invasive species as a high-quality and valuable shellfish product. [ABSTRACT FROM AUTHOR]

Global temperatures are rising across marine ecosystems in response to climate change. Marine and estuarine-dependent species including the blue crab, Callinectes sapidus, may adapt to warming temperatures phenologically, by shifting the seasonal timing of biological events, such as reproduction. In Chesapeake Bay, average water temperatures have risen by an average 0.02°C per year since the 1980s. Extension of the blue crab spawning season, through earlier onset and later conclusion, may augment annual brood production and alter the efficacy of management strategies. The duration of the potential spawning season from 1985 to 2019 was assessed using degree days, and the observed spawning season from 1995 to 2019 was assessed using the occurrence of ovigerous crabs from the Virginia Institute of Marine Science Trawl Survey in the James River and in the mainstem of lower Chesapeake Bay. Spawning degree days (SDD) and reproductive degree days (RDD) were defined using minimum temperatures of 19°C and 12°C, respectively. The mean duration of the potential spawning season increased by 25% in SDD and 10% in RDD between 1985 and 2019 in the James River and lower Chesapeake Bay, respectively. This progressive expansion of the potential spawning season was not, however, reflected in the observed spawning season. Rather, the onset, conclusion, and duration of the observed spawning season were variable over the time series. The observed month of onset was driven by RDD in spring, whereby spawning began earlier during warmer springs. The spawning conclusion date was driven by the onset of spawning, rather than Fall temperature, such that the duration of the observed spawning season and, therefore, annual brood production did not change over time. In Chesapeake Bay, the spawning stock is protected by a sanctuary that is closed to fishing from mid-May to mid-September during the putative spawning season. An earlier start to the spawning season during warmer springs, as seen in recent years, is expected to reduce the efficacy of the spawning sanctuary and intensify exploitation of the spawning stock, without enhancing brood production, thereby reducing reproductive output of the blue crab population in Chesapeake Bay. [ABSTRACT FROM AUTHOR]

In Thailand, the populations of a commercially important crab Portunus pelagicus (Linnaeus, 1758) have been decreasing due to overfishing, raising concerns about the conservation efforts of this crab species. The Crab Bank Project has recently been established to restore crab populations by releasing crab larvae from each crab bank station. However, the fate of crab larvae after the release is poorly understood. Here, we assessed the dispersal and settlement patterns of the larvae P. pelagicus released from crab banks along the coast of Trang Province, Southern Thailand. The Lagrangian particle tracking model was employed to simulate the larval dispersal and settlement patterns after release from the crab banks during the inter-monsoon, southwest monsoon, and northeast monsoon. Our simulation revealed that virtual larvae were predominantly retained within inshore areas after the release for 14 days, regulated by tidal-driven currents, wind-induced currents, and local coastal topography. Monsoon periods affected the larval dispersal, with some larvae being transported into estuaries due to the SW monsoonal effects. After the 14-day release period, our modelled simulations suggested that the crab larvae arrived at numerous seagrass meadows along the coast, indicating potential settlement and growth. This result highlights the connectivity of sources and sinks for crab larvae after release from crab banks. Moreover, significant implications for conservation efforts and the fishery management of P. pelagicus were also discussed based on our modelled simulations. [ABSTRACT FROM AUTHOR]

Predator–prey interactions structure ecological communities, and personality can significantly mediate these interactions. Personality expression is often contingent on social context, suggesting that group personality may be key in determining the outcomes of predator encounters. Here, we test the influence of individual personality and group composition on survival of the marsh periwinkle, Littoraria irrorata , when exposed to its main predator, the blue crab, Callinectes sapidus , both integral players in mediating the productivity and health of salt marsh ecosystems. Snails were categorized as having bold or shy personality types, which were unrelated to shell length, though neither trait influenced survival when individual snails were exposed to a predator. However, when snails were partitioned into groups differing in personality composition, snails in groups with bold individuals had higher survival than those in groups with none. While group type did not influence the survival of bold snails, shy snails performed better in mixed groups: the presence of a few bold individuals emerged as especially effective in decreasing mortality of shy snails. The effect of personality on predator escape is thus conditional on group personality composition, indicating that social context can directly impact the survival and success of its individual members, with broad implications for community dynamics. [ABSTRACT FROM AUTHOR]

In the past few years, non-native blue crab has been expanding its range in the Adriatic and Mediterranean Seas. However, when non-indigenous species establish a lasting presence in a novel ecosystem and actively expand into other regions, posing potential risks to local biodiversity and economic harm, they are classified as invasive species. For this study, two different batches of blue crabs were collected: one from the Mediterranean Sea and the other from the Adriatic coast area. Considering the negative ecological impact that blue crab has had and continues to have on the Italian coasts, this work was aimed to evaluate the characteristics of the Adriatic Sea “variant”; another goal was to propose the potential use of blue crab as a commercially profitable source due to its organoleptic characteristics. Data obtained revealed a high protein content, a good lipid profile, a low number of plastic particles, and the absence of toxic metals and pathogenic microorganisms. A deep statistical analysis was conducted to compare different portions of blue crab from the Adriatic and Mediterranean Seas. The results suggest that Callinectes sapidus is beneficial for human consumption and represents a valuable seafood, and its carapace could be used as compliant feed for aquaculture due to its metal composition and microbiological content.

Catches from the small-scale trap fishery in Bandon Bay, Suratthani, Thailand, were monitored from 14 sites around the Bay, then disturbance to aquatic communities and catch assemblage were examined. At the same time, the hydrographical features of the bay were surveyed. The study was conducted throughout 2019 except in December, when a tropical cyclone made sampling impossible. In total, 17,373 animals from 118 species or species groups of aquatic animals were collected. The main target of the fishery, blue swimming crab Portunus pelagicus, contributed about 10% of the total catch in terms of number; meanwhile, another crab, Charybdis affinis, was the most dominant species (41% of total). W-statistics of Abundance-Biomass Comparison curves ranged between -0.025 and 0.031, indicating light disturbance to the communities in this fishing ground. The catch assemblage, based on number in catch composition, were divided into three main clusters and six sub-clusters by using the self-organizing map (SOM) technique. The SOM results showed that the catch assemblages differed based largely on temporal variation. The hydrographic features of Bandon Bay at times exhibited a layered structure and had strong spatial variation. The bay's current system was governed by motion of tidal currents; meanwhile, the circulation was governed by monsoonal wind and freshwater discharges. Tidal current was strong and ranged between approximately 0.6 m to 2.2 m. Water within the bay was always warmer than the outer sea. High water temperature was observed two times during the year: during monsoon transition 1 (April to May) and transition 2 (October). Salinity showed great spatial and temporal variation, differing by more than 5–10 ppt horizontally. It was possible to use these dynamic hydrological features of Bandon Bay to explain assemblage patterns of the trap-net catches. [ABSTRACT FROM AUTHOR]

Background: Crustacean female sex hormone (CFSH) controls gradually developing adult female-specific morphological features essential for mating and brood care. Specifically, ovigerous hairs are developed during the prepuberty molt cycle of the blue crab Callinectes sapidus that are essential for carrying the eggs until they finish development. Reduced CFSH transcripts by CFSH-dsRNA injections result in fewer and shorter ovigerous hairs than the control. This study aimed to identify the specific genes responsible for ovigerous hair formation using transcriptomic, genomic and expression analyses of the ovigerous setae at three stages: prepuberty at early (OE) and late premolt (OL), and adult (AO) stages. Results: The de novo Trinity assembly on filtered sequence reads produced 96,684 Trinity genes and 124,128 transcripts with an N50 of 1,615 bp. About 27.3% of the assembled Trinity genes are annotated to the public protein sequence databases (i.e., NR, Swiss-Prot, COG, KEGG, and GO databases). The OE vs. OL, OL vs. AO, and OE vs. AO comparisons resulted in 6,547, 7,793, and 7,481 differentially expressed genes, respectively, at a log2-fold difference. Specifically, the genes involved in the Wnt signaling and cell cycle pathways are positively associated with ovigerous hair development. Moreover, the transcripts of ten cuticle protein genes containing chitin-binding domains are most significantly changed by transcriptomic analysis and RT-qPCR assays, which shows a molt-stage specific, down-up-down mode across the OE-OL-AO stages. Furthermore, the expression of the cuticle genes with the chitin-binding domain, Rebers and Riddiford domain (RR)-1 appears at early premolt, followed by RR-2 at late premolt stage. Mapping these 10 cuticle protein sequences to the C. sapidus genome reveals that two scaffolds with a 549.5Kb region and 35 with a 1.19 Mb region harbor 21 RR1 and 20 RR2 cuticle protein genes, respectively. With these findings, a putative mode of CFSH action in decapod crustaceans is proposed. Conclusions: The present study describes a first step in understanding the mechanism underlying ovigerous hair formation in C. sapidus at the molecular level. Overall, demonstrating the first transcriptome analysis of crustacean ovigerous setae, our results may facilitate future studies into the decapod female reproduction belonging to the suborder Pleocyemata. [ABSTRACT FROM AUTHOR]

Blue crab (Callinectes sapidus) is a highly valuable wild fishery species of crab native to the waters of the western Atlantic Ocean and the Gulf of Mexico. The annual commercial production of live blue crabs is approximately 50,000 metric tons with a dockside value of USD 200 million. Presently the US blue crab processing industry sells crab meat in three basic forms: fresh crab meat, pasteurized crab meat, and frozen crab meat. By far "Fresh" is the most desirable form of crab meat. However, fresh crab meat has a limited shelf life. This study evaluated the effects of high-pressure processing (HPP) on enhancing the microbiological quality and shelf life of blue crab meat. Live blue crabs were pressure-cooked in a retort (≥115 °C for 4–6 min). The crab meat was handpicked, packed in plastic containers with seals, subjected to HPP treatment, and stored at 4 °C. Container integrity and water leakage issues were examined by observation in addition to weight comparison before and after HPP treatment; the shelf life of crab meat with and without HPP treatments was examined via microbiological tests and sensory evaluations. Results show that polypropylene containers sealed with 10K OTR (oxygen transmission rate) film could withstand high pressure without water leakage issues; HPP treatment at 600 MPa for 3 min could extend the shelf life of fresh, cooked, and handpicked crab meat from 6 days to 18 days based on the strictest APC (aerobic plate account) limit (APC ≤ 100,000 CFU/g). The sensory quality of the HPP-treated crab meat was well accepted throughout the 3-week storage period. The results support the use of HPP as an effective non-thermal processing technology to enhance the microbiological quality and extend the shelf life of fresh RTE blue crab meat. [ABSTRACT FROM AUTHOR]

The introduction of non-indigenous species to aquatic ecosystems is one of the main threats to global biodiversity. This paper reports the occurrence of the blue swimmer crab Portunus segnis in southwestern European waters (i.e., the Gulf of Cadiz). We discuss the invasive potential of P. segnis and possible mechanisms of its expansion into this new region. The detection of this species also highlights the importance of involving citizen scientists in the reporting of non-indigenous species. [ABSTRACT FROM AUTHOR]

A single Blue swimming crab Portunus segnis was captured on November 5th 2022 close to the harbor of Ancona, off the central Adriatic coast (Italy) by artisanal fishers. Taxonomic comparisons were performed with collection materials, which also included two unreported specimens of the species from the Ionian coast of Calabria, Italy. The large distance between the Adriatic record of P. segnis and its invasion front, reinforces the hypothesis that human-mediated translocations contribute to the secondary dispersal or introduction of this invasive species in Mediterranean waters. [ABSTRACT FROM AUTHOR]

The blue crab (Callinectes sapidus) is ecologically and economically important in Chesapeake Bay. Nursery habitats, such as seagrass beds, disproportionately contribute individuals to the adult segment of populations. Salt marshes dominated by smooth cordgrass Spartina alterniflora are intertidal nursery habitats which may serve as a refuge from predation for juvenile blue crabs. However, the effects of various characteristics of salt marshes on nursery metrics, such as survival, have not been quantified. Comparisons of juvenile survival between salt marshes and other habitats often employ tethering to assess survival. Although experimental bias when tethering juvenile prey is well recognized, the potential for habitat-specific bias in salt marshes has not been experimentally tested. Using short-term mesocosm predation experiments, we tested if tethering in simulated salt marsh habitats produces a habitat-specific bias. Juvenile crabs were tethered or un-tethered and randomly allocated to mesocosms at varying simulated shoot densities and unstructured sand. Tethering reduced survival, and its effect was not habitat specific, irrespective of shoot density, as evidenced by a non-significant interaction effect between tethering treatment and habitat. Thus, tethering juvenile blue crabs in salt marsh habitat did not produce treatment-specific bias relative to unvegetated habitat across a range of shoot densities; survival of tethered and un-tethered crabs was positively related to shoot density. These findings indicate that tethering is a useful method for assessing survival in salt marshes, as with other nursery habitats including seagrass beds, algae and unstructured sand. [ABSTRACT FROM AUTHOR]

Introduction: Fluctuations in environmental physicochemical parameters can affect the diversity and prevalence of microbial communities, including vibrios, associated with aquatic species and their surrounding environments. This study aimed to investigate the population dynamics of two Vibrio species as well as the microbial community diversity of whole crab and seawater from the Maryland Coastal Bays (MCBs), using 16S rRNA sequencing. Methods: During this study, three crabs and 1 L of seawater were collected monthly from two sites for 3 months. Crab tissue was extracted and pooled for each site. Extracted crab tissue and seawater were analyzed for Vibrio parahaemolyticus and V. vulnificus using Most Probable Number (MPN) real-time PCR. For 16S rRNA microbiome analysis, three different DNA extraction kits were evaluated to extract microbial DNA from individual crabs. Also, 500 mL of each seawater sample was filtered for DNA extraction. Results: Results indicated that sample types and sampling periods had a significant effect on the alpha diversity of the microbial community of crabs and seawater (p < 0.05); however, no statistical difference was found between DNA extraction kits. Beta diversity analysis also found that the microbial compositions between sample types and temporal distributions were statistically significant. Taxonomic classification revealed that Proteobacteria, Cyanobacteria, Actinobacteria, and Bacteroidetes were present in both crab and seawater samples. Vibrio parahaemolyticus and V. vulnificus were also detected in both crab and seawater samples, although crabs contained a higher concentration of the bacterium compared to the seawater samples. It was found that vibrios were not a dominant species in the microbial community of crab or seawater samples. Discussion: Results from this study provide further insight into species diversity and phylogenetic compositions of blue crabs and seawater from the MCBs. These approaches will help in risk assessments that are essential in the overall advancement of public health. [ABSTRACT FROM AUTHOR]

Objective: The diamondback terrapin Malaclemys terrapin is frequently caught as bycatch in both commercial and recreational blue crab Callinectes sapidus fisheries throughout its range along the Atlantic and Gulf coasts of North America. Bycatch reduction devices (BRDs) are plastic or wire rectangles mounted in the entrance funnels of crab traps, designed to exclude terrapins while still allowing crabs to enter. In this study conducted in two tidal creeks in Virginia, USA, we assessed the effectiveness of four BRD designs, including two novel oval designs, against control traps with no BRDs. Methods: We tested four replicates of each of the five trap treatments (1.75‐inch oval BRD, 2‐inch oval BRD, 1.75‐inch rectangular BRD, 2‐inch rectangular BRD, and a control trap without a BRD) in each tidal creek, for a total of 20 traps per creek and 40 traps total. We fitted traps with wire chimneys that extended above the high tide water line to allow trapped terrapins to surface for air. For eight weeks during summer 2021, we baited traps with Atlantic Menhaden Brevoortia tyrannus each day, beginning on Monday. Tuesday–Friday, we emptied traps of any animals inside, and recorded terrapin sex, terrapin carapace length, terrapin carapace width, and terrapin shell height, as well as blue crab carapace length. Result: We found that all four BRD designs were highly effective at excluding terrapins and maintaining crab catch when compared to control traps. We found a significant difference (p = 0.003) in catch per unit effort (CPUE) of diamondback terrapins among treatments, with the control group (those without BRDs) having the highest CPUE (0.97 ± 0.18). All traps fitted with BRDs decreased terrapin capture significantly compared to the control group. Oval BRDs excluded more terrapins than their rectangular counterparts with the same height dimension, although these differences were not significant. We found no significant difference in CPUE of blue crabs among treatments (p = 0.392), or in the size of legal crabs caught in each treatment (p = 0.216). Conclusion: This study provides evidence of the effectiveness of both rectangular and oval‐shaped BRDs to exclude terrapins and maintain crab catch in Virginia waters, where BRDs are not currently required. Impact statementDiamondback terrapins often drown in blue crab traps, especially in tidal areas. We found that oval and rectangular bycatch reduction devices reduce terrapin bycatch and maintain crab catch. Bycatch reduction devices of any type are an easy way to aid in terrapin conservation when fishing for blue crabs. [ABSTRACT FROM AUTHOR]

Objective: Predatory invasive fishes may consume species of management interest and alter food webs. Blue Catfish Ictalurus furcatus is a large‐bodied, salinity‐tolerant species that exhibits broad diet breadth and preys on species of both conservation concern and fisheries management interest. To better understand the ecological consequences of the establishment of Blue Catfish fisheries, estimates of predatory impacts are needed. Methods: Using a Monte Carlo simulation, we integrated abundance estimates, diet information, and consumption‐to‐biomass ratios to estimate population‐level Blue Catfish predation for a large Chesapeake Bay tributary along the mid‐Atlantic coast of the United States, the James River. Result: Population‐level annual predation estimates by Blue Catfish exceeded 100 metric tons for several species or taxa of interest, including an estimated 400.7 metric tons (95% CI = 272.6–613.2) of blue crab Callinectes sapidus. Prey species abundances were unknown and thus limited opportunities to evaluate prey population responses. For instance, effects of Blue Catfish on blue crab populations remain unknown without tributary‐specific estimates of blue crab abundance, but comparisons to landings data suggests that Blue Catfish predation on blue crab in the James River may be low compared with harvest. Conclusion: Estimation of Blue Catfish predatory effects may inform development of management goals and objectives that balance diverse stakeholder interests. This work provides beneficial information to assess trade‐offs of Blue Catfish fisheries and their effects on coastal aquatic resources. Impact statementThis work provides estimates of predatory effects of a nonnative Blue Catfish population in the tidal James River, Virginia, USA. The results could inform management planning by improving our understanding of potential effects on other species of management interest. [ABSTRACT FROM AUTHOR]

As recreational fishers act relatively autonomously, management relies heavily on voluntary compliance. Therefore, understanding fishers' views on management options can be beneficial. This study used a two-phase approach of face-to-face interviews and subsequent online questionnaires to evaluate recreational fishers' salient views on issues affecting the Blue Swimmer Crab (Portunus armatus) and Black Bream (Acanthopagrus butcheri) fisheries in Western Australia as well as current and potential management arrangements, including stock enhancement. The strength and heterogeneity of views were also determined. Minimum size limits were mainly considered acceptable or very acceptable, with restricting recreational fishing and spatial closures the least supported management options for both species, in addition to maximum size limits for crabs. These views were not always consistent across fishing locations for each species and among types of crab fishers, indicating heterogeneity in views. Stocking was the most acceptable of the management measures not already utilised for crabs and among the most popular for bream fisheries. Recreational fishers of both species believed stock enhancement could have strong positive outcomes for the abundance of their target species and increase their subsequent catches. They also recognized that some negative outcomes, e.g., increased fishing pressure and environmental issues, might occur but considered them unlikely. [ABSTRACT FROM AUTHOR]

The blue swimmer crab, Portunus pelagicus, is an edible abundant crustacean found in many seas around the world, including the Arabian Gulf. In this study, the concentrations of six metal ions in the white and brown meats of P. pelagicus from four sites in Bahrain were determined. P. pelagicus was found to accumulate Zn2+ and Cu2+ higher than other metal ions in the order of Zn2+ > Cu2+ > Cd2+ > Ni2+ > Cr3+, while Pb2+ was not detected. The overall average concentrations of Zn2+, Cu2+, Cr3+, Ni2+, and Cd2+ in white meat were 236.2, 69.5, 0.109, 0.159, and 0.273 mg/kg, while in brown meat, they were 235.4, 199.2, 0.133, 1.25, and 4.87 mg/kg based on dry weight, respectively. Concentrations of Pb2+ and Cd2+ were safe according to Bahrain's and European Commission guidelines. The estimated weekly intake (EWI) values of Zn2+, Cu2+, Pb2+, and Cd2+ via consumption of crab's white meat (edible tissue) were 102.1, 30.1, 0.042, and 0.12 µg/kg/week, respectively, which are far lower than the maximum recommended values established by the FAO/WHO. The hazard quotient (HQ) values of individual trace metal ions and the synergistic effects of total trace metal ion (hazard index) were below 1, indicating that there is no potential health risk on the consumption of crab edible tissues (white meat). However, elevated levels of Cd2+ (0.05–1.73 mg/kg wet weight) in the brown meat (hepatopancreas) were detected. The female P. pelagicus accumulated high levels of Zn2+ and Cu2+ in the white meat, as well as Cu2+ in the brown meat compared to males. Additionally, it was found that Cu2+ and Cd2+ were significantly higher (p < 0.05) in brown meat compared to white meat. Higher concentrations (p < 0.05) of Zn2+, Cu2+, and Cd2+ were observed in crabs collected from sites that have harsher environmental conditions. [ABSTRACT FROM AUTHOR]

The blue crab Callinectes sapidus (Rathbun, 1896) is one of the most invasive species in the Mediterranean Sea. Understand how the populations are maintained and how the environment is driving the populations in the areas invaded is the key to an effective future management. This current study is presenting a monthly long-term monitoring of the blue crabs' population structure, body size, sexual maturity, reproduction periods and fecundity, and their relationships with environmental factors in a saltmarshes system in Italy. During winter, high densities (15 ± 8 ind m-2) of early juveniles (< 2 cm) were observed, and their numbers decreased due the population growth until summer. The size-spectra showed that across different temperature (18–26°C) and salinity (24–40 psu) gradients, the growth period for males is faster than for females. Based on abdominal analysis, sexual maturity was defined at ∼12 cm for males and females but the population was in favor of males that were more than 66% of the time mature throughout the year. Copulations periods were identified between spring and autumn when more than 50% of females were matures, and ovigerous females' migrations were observed in late summer. Our study expand our understanding of how the environment interacts to effect physiological and biological processes of alien species and improve our ability to make predictions of how environmental change the distribution of the alien species in the future. Based on our results, we also discuss which population control strategy would be most effective based on the data available in the literature. [ABSTRACT FROM AUTHOR]

The recovery and recycling of wasted resources are at the forefront of contemporary global issues. Methods of addressing several different issues may go hand-in-hand with each other, such as linking food waste recycling into bio-based adsorbent materials and wastewater treatment. Crustacean exoskeletons are promising candidates for bio-friendly adsorbents; however, maximizing their efficiency requires the optimization of processing technology. Crustacean meat offers an (often luxury) culinary delicacy, while their waste exoskeletons offer opportunities for smart recycling of the magnesian calcite nanoporous biocomposite. Here, we conduct a structural characterization of the exoskeletons of three crustacean species to assess how the extraction of valuable carotenoids affects prospects for the further valorization of their porous powder. The exoskeleton powder's composition and morphology were investigated by SEM, Raman spectroscopy, FTIR and XRD. The biomineral component magnesian calcite was recorded both in native and in post-extraction exoskeleton powder. Acetone extraction, however, partially removed organic matter from the exoskeletons, resulting in the porosity of the respective powder increasing significantly from below 10 m2 g−1 in the native powder to over 32 m2 g−1 in post-extraction samples of blue crab and spider crab exoskeletons—while the spiny lobster exoskeleton exhibited low porosity, as measured by the BET method. This new insight could improve exoskeleton processing in the sustainable circular economy and applied blue bioeconomy—most notably for adsorbent materials for pollutants dissolved in water or as ordered, nature-derived nanostructured templates. [ABSTRACT FROM AUTHOR]

The concentrations of metals (Cd, Cr, Cu, Fe, Mn, Ni, Zn, Pb, Al) were evaluated in the blue crabs (Callinectes sapidus) tissues collected in January, April, June and September 2022 at two stations in Gharb region of Morocco (lagoon Merja Zerga, Nador canal) using ICP-MS. The metal concentrations in crabs from two stations was not differed significantly. The gill was the major organ accumulating metals, followed by hepathopancreas and muscle tissues. Except for Cadmium, the highest concentrations of metals were measured in the gill. The gill had higher concentrations of all heavy metals except for Fe (Cr 7.37 ± 0.05; Zn 149.9 ±0.05; Ni 2.88 ± 0.025; Cd 1.28 ± 0.1; Mn 136.72 ± 0.075; Fe 530.25 ± 0.075; Cu 138.17± 0.125; Al 179.25±0.1; Pb 27.1±0.025) in Merja zerga and (Cr 8.61± 0.05; Zn 125. 62±0.05; Ni 3.77± 0.025; Cd 1.24± 0.1; Mn 204.42 ± 0.075; Fe 380.75 ± 0.075; Cu 166.22 ± 0.125; Al 230 ±0.1; Pb 34.35±0.025) in Nador canal compared to muscle (Cr 5.22 ± 0.05; Zn 135.7± 0.05; Ni 2.44 ± 0.025; Cd ±1.34 0.1; Mn 245.95 ± 0.075; Fe 656 ± 0.075; Cu 156.62 ± 0.125; Al 229.25 ±0.1; Pb 11.92 ±0.025) in Merja zerga and (Cr 2.92 ± 0.05; Zn 168.82 ±0.05; Ni 2.05 ± 0.025; Cd 1.22 ± 0.1; Mn 141.25 ± 0.075; Fe 430.5± 0.075; Cu 155.4 ± 0.125; Al 254±0.1; Pb 20.35 ±0.025) in Nador canal. Among the metals analyzed, Cu, Zn, Fe, Al and Mn were the most abundant in the different tissues while Cd was the least abundant in C. sapidus. Seasonality in the levels of the nine metals was determined. the highest concentrations of all metals were observed in Autumn. [ABSTRACT FROM AUTHOR]