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Abalone is a gourmet seafood with a high commercial value, particularly when obtained as a live product. During live transportation, abalone encounter stressors causing biochemical modifications to tolerate the changes. Using semi-targeted metabolomics, this study characterised the left and right gill metabolite profiles of Blackfoot abalone, Haliotis iris, following transportation (48 h) and recovery (48 h). This study reports the association between left and right gill metabolites, to enhance our physiological understanding of the interplay between gills. The left gill metabolites are mainly active following transportation, while both gills partake in the metabolite response following recovery. Transportation necessitated increased metabolites linked to the glycolysis pathway, the Krebs cycle, amino acid, and nucleotide metabolism, for energy production, achieved via aerobic and anaerobic pathways. The recovery phase supported the replenishing of glycogen, triglycerides, and protein stores, albeit metabolic homeostasis was not achieved following two-days of water immersion recovery. This study showcases the well-adapted metabolic mechanisms implemented by H. iris in response to transportation stress and show that metabolites are in the process of returning to the same concentrations as measured pre-transport stress. The findings herein can be applied to improve animal health during transport and subsequent survival, which in-effect supports profitability. [ABSTRACT FROM AUTHOR]

The endemic, green-lipped mussel (Perna canaliculus), trademarked as Greenshell™ mussel, contributes most to the New Zealand aquaculture industry based on tonnage and export value. Research on mussel immunity is motivated greatly by economical and biosecurity necessities. Indeed, mussel aquaculture is threatened by pathogenic micro-organisms and environmental stressors. As such there is a need to understand the mechanisms that drive mussel immune responses and the associated interactions with the environment. Specifically, this review (1) analyses the existing immunological studies conducted on P. canaliculus, (2) evaluates the literature pertaining to mussel immunity at the cellular and humoral levels, (3) identifies and discusses pathogens that are relevant to P. canaliculus, (4) focuses on the virulent factors employed by mussel pathogens likely to induce diseases, (5) provides a comprehensive analysis of the response mechanisms employed by mussels to various stressors, and (6) explores omics applications and future perspectives in mussel immunology. Finally, this review highlights various strategies from immunological research, such as gene rearrangement, probiotics, immunostimulants, and selective breeding, promising to enhance mussel health and resilience in aquaculture. By exploring these immunological findings and their practical applications, this review contributes to sustainable mussel aquaculture, improving productivity and disease management in the industry. [ABSTRACT FROM AUTHOR]

Marine organisms are constantly exposed to stress, such as changes in seawater temperature, which may elicit biochemical, molecular, and physiological changes. In the present study, an integrative approach to evaluate stress in the green-lipped mussel Perna canaliculus exposed to control, moderate, and severe heat stress was used. Flow cytometry (FCM) was used to measure hemolymph parameters, including hemocyte concentration, viability, and reactive oxygen species (ROS) production. Spectrophotometry and a handheld electrochemical meter were used to determine the total antioxidant capacity (TAC) of hemolymph and gill tissue, and metabolomics was used to contrast specific metabolic responses among treatments. For hemolymph parameters measured using FCM, the number of nonviable hemocytes increased with the severity of heat shock. The proportion of superoxide-positive hemocytes mirrored the increase in nonviability; by contrast, the general ROS production initially increased following moderate heat shock, but then decreased after severe heat shock. Trolox-equivalent antioxidant capacity in the gill tissue and fast-acting antioxidant levels in the haemolymph showed small but significant decreases following heat shock, whereas the reciprocal pattern was seen for slow-acting and TAC in the hemolymph. Metabolomic profiles discriminated between treatments, with energy metabolism pathways appearing the most affected. The approach used in this study provides a deeper mechanistic understanding of the stress responses of organisms exposed to heat stress; however, these analytical techniques may be combined or used independently to measure stress in marine organisms in the laboratory or in the field, which can improve health assessments of wild and farmed aquatic organisms. KEY WORDS: mussel, Perna canaliculus, hemocytes, ROS, antioxidant capacity, flow cytometry, electrochemistry, redox, metabolites, biomarker, aquaculture, climate change, INTRODUCTION Marine invertebrates are constantly being challenged by changes in environmental conditions and other stressors such as changes in seawater temperature, salinity, and pH, which will only become more prevalent [...]

Background: The decrease in the production of Argopecten purpuratus scallops in Chile is linked to extensive larval deaths in hatcheries caused by bacterial pathogens, particularly Vibrio genus, threatening sustainability. Traditional antibiotic practices raise concerns, urging research on eco-friendly strategies like bacterial probiotics. This study explores the metabolic responses of scallop larvae to Vibrio bivalvicida and evaluates the impact of the Psychrobacter sp. R10_7 probiotic on larval metabolism pre- and post-infection. Materials and Methods: Analysis detected 183 metabolite features, revealing significant changes in larval metabolites during Vibrio infection. Larvae pretreated with probiotics showed a metabolic profile comparable to non-infected larvae, indicating low impact on larval metabolome, likely due to probiotics antagonistic effect on pathogens. Results: Arachidonic acid, eicosatrienoic acid, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and docosapentaenoic acid (DPA) were significantly higher in non-pretreated/infected larvae compared to both pretreated/infected and non-pretreated/non-infected larvae, potentially supporting the activation of immune response in non-pretreated larvae to Vibrio infection. Identification of 76 metabolites provided insights into scallop larvae metabolome, highlighting the enriched metabolic pathways associated with energy provision and immune response. Conclusions: Probiotic pretreatment may mitigate metabolic disruptions in scallop larvae caused by Vibrio infection, suggesting a promising strategy for sustainable scallop production. [ABSTRACT FROM AUTHOR]

The New Zealand's Greenshell™ mussel (Perna canaliculus) aquaculture industry is being affected by summer mortality events associated with increasing seawater temperatures and pathogens. In this study, challenge experiments were conducted to investigate, for the first time, the effects of pathogen coinfection on the survivability and haemolymph immune responses of juvenile and adult mussels. Animals were injected with marine broth (control), Vibrio mediterranei, Photobacterium swingsii, or a mixture of V. mediterranei and P. swingsii. Then, mussel survival was monitored for 72 h, and haemolymph was sampled for bacterial quantification and metabolomics analyses at 24‐ and 48‐h post challenge. Coinfected adults and juveniles showed 100% mortality. Bacterial colony counts in haemolymph decreased as infection time continued, especially in juveniles. The haemolymph metabolome of mussels exposed to single bacterial species and coinfection showed response changes largely within energy metabolism. Mussels infected with V. mediterranei exhibited increased metabolites linked to the glutathione pathway, branched‐chain amino acids, and others over time, supporting structural functions. Conversely, mussels infected with P. swingsii showed no metabolic differences over time. The coinfection group exhibited large decreases in important metabolites, such as fatty acids as an alternative energy source and amino acids to support immune functions and protein synthesis. [ABSTRACT FROM AUTHOR]

The New Zealand Journal of Marine & Freshwater Research presents a special issue dedicated to selected papers from the 11th International Abalone Symposium, focusing on 'Abalone research in a changing world'. The symposium, held in Tāmaki Makaurau (Auckland), New Zealand, featured a diverse range of topics including fundamental biology, commercial fisheries, aquaculture, and cultural knowledge, with contributions from 220 delegates representing 15 countries. The 16 manuscripts in this special issue cover various aspects of abalone research, such as production figures, restoration efforts, dietary interventions, co-culturing, omics applications, age determination, and fisheries management, showcasing a global perspective on species like Haliotis asinina, H. iris, H. laevigata, and others. The editorial team expresses gratitude to the authors, reviewers, and publishing team, hoping that this collection of research will inspire future endeavors to support the success of abalone. [Extracted from the article]

This study assessed the selected peripheral blood haematological parameters and metabolite profiles linked to liver, serum and muscle samples in 3‐year‐old male (weight = 131.19 ± 29.24 g; total length = 21.33 ± 1.20 cm; n = 5) and female (122.96 ± 27.04 g; total length = 21.09 ± 1.09 cm; n = 5) giant kokopu (Galaxias argenteus) broodstock cultured at 12°C and 16°C. Temperature and sex did not influence haematocrit values or counts of total blood cells, erythrocytes and leucocytes. However, fish reared at 16°C had higher thrombocyte counts, whereas those kept at 12°C exhibited the highest proportion of lymphocytes. At the metabolic level, sex was the main factor that influenced metabolite levels across tissues, with particularly higher amino acid metabolites in liver of females. Changes linked to the interaction between temperature and sex showed significant differences in fatty acid profiles of liver, and in amino acids in muscle and serum samples. Males kept at 16°C exhibited decreased levels of myristic acid and nonadecanoic acid linked to homeoviscous adaptation. In females, levels for energy metabolites including tyrosine and aspartic acid (in muscle), and alanine (in serum) were disturbed at 16°C. The study provides insights into preliminary haematological and metabolic effects associated with sex and temperature in galaxiids. [ABSTRACT FROM AUTHOR]

Abalone is currently considered South Africa's most successfully produced aquaculture export product, with a 76% share of the total value generated by the aquaculture sector. A major risk factor for this sector is slow growth rates experienced during farming. Abalone feeds are often supplemented with amino acids in an attempt to enhance abalone growth. This is a first investigation of the effect of added proline to standard abalone feed, on the metabolite profile of slow‐growing abalone. A targeted liquid chromatography tandem mass spectrometry metabolomics research approach was followed to recognise the metabolic response of abalone showing slower growth performance. The addition of proline to the standard abalone diet was found to serve as a substrate for amino acid catabolism in slower growing abalone, by means of proline breakdown to assist with energy production via the tricarboxylic acid cycle. Other amino acids and urea cycle intermediates, that is, arginine, asparagine, ornithine and creatine further support energy production via the action of protein catabolism in slow‐growing abalone. Additionally, the importance of understanding how abalone respond metabolically to modified feed highlights the use of metabolomics to answer abalone aquaculture farming questions. [ABSTRACT FROM AUTHOR]