The brine shrimp Artemia is a crucial component of hypersaline ecosystems and an indispensable live feed in aquaculture. Algeria hosts diverse Artemia populations across its coastal salterns, inland chotts, and sabkhas in the High Plateaus and Sahara. This review synthesises current knowledge of Algerian Artemia, covering taxonomy, genetic diversity, spatial distribution, reproductive biology, biochemical composition, exploitation, and aquaculture potential, based on an extensive analysis of available literature. Algerian Artemia biodiversity includes the native bisexual species Artemia salina and both diploid (2n) and tetraploid (4n) parthenogenetic strains (parthenogenetic Artemia), often co-occurring with seasonal alternation influenced by temperature and salinity. Populations inhabit environments with wide physicochemical fluctuations, particularly in salinity (ranging from 40 g/L to over 300 g/L) and temperature, often exhibiting ephemeral characteristics that necessitate cyst production for survival. Main sites like Chott Marouane and Sabkha Ez-Zemoul support significant populations, but reproductive traits and biochemical profiles vary among strains. Notably, Algerian strains are generally deficient in the essential fatty acids eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3), requiring enrichment for optimal use in marine larviculture. While natural populations represent a potential resource for the national aquaculture sector, challenges include habitat degradation, climate change impacts, potential competition from invasive species, difficulties in sustainable harvesting, and the need for optimised culture and enrichment protocols. Further research, particularly using molecular tools and focusing on ecological dynamics and sustainable management, is crucial for the conservation and effective utilisation of Algeria’s valuable Artemia resources.

The expansion of aquaculture often faces challenges related to environmental impacts and social acceptance, particularly when involving exotic species. In Argentina, where marine aquaculture remains marginal, recent proposals for salmonid farming in Tierra del Fuego province (TDF) have sparked public debate, balancing economic development against environmental concerns. In response, the local government enacted Law 1135/2021, banning salmonid farming in the province. This study explores public attitudes toward exotic salmonid aquaculture in TDF using a mixed-methods approach, combining press discourse analysis with an extensive online survey. Results indicate strong public resistance to net-pen salmonid farming in the Beagle Channel, especially among TDF residents and individuals linked to environmental sciences. In contrast, land-based aquaculture and farming of native species receive more support. Most respondents doubt the economic benefits of salmonid farming, and nearly 80% of TDF residents support the ban. Notably, while there is strong opposition to new exotic introductions, most respondents do not support eradication of established salmonid populations, which are widely accepted due to their long-standing presence and importance for recreational fishing. These findings reflect the nuanced views of the local community and emphasize the need for socially informed and transparent regulatory frameworks for aquaculture development in ecologically sensitive regions.

South Asia presents a striking nutritional paradox: populations among the world’s highest fish consumers carry disproportionate cardiometabolic risk at BMI levels well below disease thresholds for European populations. Marine fish is established as cardioprotective in fatty-fish-consuming coastal populations, yet this benefit appears to break down in South Asian contexts. This commentary interrogates four interlocking mechanisms. First, aquaculture-driven species substitution has replaced n-3-rich species such as hilsa and coastal sardines with leaner farmed varieties offering only a fraction of the cardioprotective lipid profile. Second, deep frying in high-n-6 oils substantially degrades PUFA bioavailability. Third, heavy metal co-contamination in arsenic- and mercury-affected watersheds may attenuate n-3 benefits. Fourth, urbanisation is eroding fish intake among the highest-risk subgroups, while aggregate dietary data obscure this heterogeneity. Generic eat-more-fish guidance is insufficient; ethnicity-sensitive, sustainability-conscious guidance on species, preparation and contamination risk is needed to realise fish’s cardioprotective potential in South Asia.

We recorded Gyrodactylus teuchis Lautraite, Blanc, Thiery, Daniel & Vigneulle, 1999 on one-year-old farmed rainbow trout Oncorhynchus mykiss (Salmoniformes, Salmonidae) from Lake Kalmozero (White Sea drainage system, Republic of Karelia, Russia) in May and October 2023. Morphological identification of these specimens was confirmed by molecular data on the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene and the ribosomal internal transcribed spacer 2 (ITS2). Analyses of the newly obtained cox1 gene sequences show they are identical to fragments of sequences of this gene for G. teuchis individuals collected from wild S. trutta in Slovenia and from farmed S. trutta in Russia. Sequencing of the ITS2 region revealed ribotype D found previously in wild S. trutta and S. fontinalis in Austria, and in farmed S. trutta and O. mykiss in Poland. The infection prevalences in the caged rainbow trout were 100% and 75%, and the mean abundances were 20.8 and 18.1 ind., in May and October, respectively. There were no significant differences between the parasite abundance distributions in these two months, likely indicating similar levels of resistance to the infection. This is the first report on G. teuchis from the White Sea drainage basin as well as in farmed rainbow trout in Russia. This new finding is a signal for veterinary authorities to strengthen parasitological monitoring of transported stocking material.

This study investigated how hormonal induction, female presence, and production system affect sperm quality in Astyanax lacustris across three experiments. In Experiment 1, males and females were kept together in the same recirculating aquaculture system (RAS) before testing. Hormonal induction consistently boosted initial motility and prolonged sperm activity, while female presence offered only a modest benefit to non-induced males and no measurable effect when males were induced. Sperm concentration remained similar across treatments. Experiment 2 evaluated the same factors using broodstock originating from different rearing environments. When males and females came from separate RAS units, hormonal induction again sustained higher motility, and induced males paired with females showed higher sperm concentration than some non-induced groups. In the RAS–biofloc technology (BFT) pairing, hormonal induction maintained motility regardless of female presence; however, in the absence of hormonal induction, both sperm motility and concentration were modulated by the rearing system of females, with non-induced males paired with BFT females exhibiting lower reproductive performance. Overall, hormonal induction proved to be the most reliable strategy for ensuring high semen quality in A. lacustris. Nonetheless, when induction was not applied, male reproductive performance became more sensitive to female origin and rearing environment, highlighting the importance of broodstock compatibility and production system history in reproductive management protocols.

Sagittal otoliths are structures that integrate the sensory system of teleost fish, assisting in balance and hearing, which are normally composed of calcium carbonate in the form of aragonite. The dusky grouper Epinephelus marginatus has great economic importance and there are already initiatives to produce this species through aquaculture. This study aimed to check the frequency of anomalous otoliths and to characterize the crystallization of sagittal otoliths in E. marginatus from a rearing system. We examined sagittal otoliths of 184 E. marginatus, most otoliths presented normal morphology (n = 152; TL = 24.0 ± 3.59 cm; OW = 0.034 ± 0.014 g), while about 17% were deformed (n = 32; TL = 29.7 ± 1.87 cm; OW mean = 0.040 ± 0.011 g). Raman spectroscopy detected aragonite deposition in all normal and anomalous otoliths. The morphological changes in otoliths of groupers may have been caused by transport between hatchery and fattening locations, by the constant flow of aeration during hatchery rearing, or even by a possible starvation period.

The study documents the embryonic and larval development of Clarias dussumieri, a Near-Threatened, cultivable, and highly valued food fish endemic to the Western Ghats. Induced breeding facilitated detailed observation of developmental stages using light microscopy. Unfertilized eggs measured 1.5 ± 0.02 mm in diameter and enlarged to 1.7 ± 0.10 mm after fertilization (∼13% increase). The first cleavage occurred at 00:36 ± 00:02 h, reaching 64 cells by 01:35 ± 00:06 h. Epiboly progressed from 30% at 03:20 ± 00:10 h to 50% at 04:30 ± 00:05 h and 90% at 05:50 ± 00:10 h; neurulation was evident by 07:40 ± 01:10 h and somites by 11:08 ± 01:26 h. The first heartbeat appeared during the pharyngula period (17:25 ± 01:30 h), and hatching occurred at 25:30 ± 01:30 h at 26–27°C. Hatched larvae were 4.2 ± 0.02 mm total length, observed few melanophores by 12 h, conspicuous eye pigmentation by 24 h, and body pigmentation spreading by day 2 (5.90 ± 0.04 mm).The yolk sac was fully absorbed by 72 ± 2.50 h post-hatching, marking the onset of exogenous feeding. By day 4 (pre-flexion), larvae reached 7.1 ± 0.02 mm; initial notochord flexion began around day 7 and post-flexion from day 10, with juvenile-like morphology evident by day 25 (15.27–17.80 mm). The standardized timelines and measurements provide a baseline for hatchery practice and conservation aquaculture of C. dussumieri, supporting protocol refinement for improving survival and growth under controlled conditions

The increasing demand for sustainable feed ingredients in aquaculture has driven research into alternative protein sources to replace fishmeal. This study evaluated the nutritional, physiological, and microbiological impacts of housefly (Musca domestica) larvae meal as a replacement for fishmeal in the diets of rainbow trout (Oncorhynchus mykiss). Diets were formulated to replace fishmeal with larvae meal at 50% and 100% inclusion levels. Growth performance, body composition, intestinal health, and gut microbiota were assessed over a 16-week feeding trial. Fish fed larvae meal-based diets exhibited comparable growth metrics, muscle yield, and hepatosomatic index to those fed fishmeal and commercial diets, indicating no compromise in growth efficiency. Intestinal histological examination revealed no diet-induced morphological changes, with all parameters remaining within normal ranges, highlighting the compatibility of larvae meal with fish intestinal health. Analysis of gut microbiota showed a shift toward Firmicutes dominance and increased abundance of Clostridiales in larvae meal-fed fish, suggesting enhanced fermentation activity. Blood chemistry parameters were consistent across dietary groups, supporting the physiological suitability of larvae meal-based diets. These findings demonstrate that housefly larvae meal is a sustainable and nutritionally viable alternative to fishmeal in aquafeeds for rainbow trout. The results underscore its potential to reduce reliance on fishmeal while maintaining fish health and growth performance.

Production of seafood has received relatively little attention in agri-food debates despite the fact that, since the 1960s, seafood production has been transformed through the industrialization of fisheries and globalization of seafood commodity chains. Intensive aquaculture emerged as a new industry in response to declining fish catches. Global commodity chains of seafood and capital accumulation processes changed tremendously, leading to complex international trade dynamics and rising inequalities. The Turkish aquaculture sector has also been transformed via government subsidies, and a few vertically integrated aquaculture companies started to produce farmed sea bass and sea bream (SBSB) in Turkish waters, while organizing their operations both upstream (processing of fish feed in Africa) and downstream (sales and distribution in Europe) in the global SBSB value chain. We adopted a single commodity approach to uncover how seafood production has been transformed via expanding commodity frontiers of capital-intensive SBSB production by focusing on the strategies of Turkish aquaculture enterprises, trade dynamics, and socio-ecological implications of SBSB production via in-depth interviews with key stakeholders and a review of legislative documents and trade data. Our analysis offers critical insights into the agrarian-change debate in Turkey by analyzing the global and regional socio-ecological inequalities created by Turkish SBSB production.

This study investigates the accumulation of glycogen, amino acids, and fatty acids in male Mytilus coruscus during different stages of gonadal development and explores their relationships with reproductive processes. Glycogen levels were highest during the resting phase, decreasing progressively during the proliferation and maturation phases. A positive correlation was observed between glycogen and carbon content, indicating a close association between energy storage and metabolic processes. Amino acid content, particularly essential amino acids (EAAs), increased during gonadal development, reflecting the higher demand for protein synthesis and cellular metabolism. Branched-chain amino acids (BCAAs) such as isoleucine, leucine, and lysine were key in activating protein synthesis and supporting gametogenesis. Non-essential amino acids like aspartic acid, glutamic acid, and glycine also accumulate, supporting cellular function and reproductive regulation. Fatty acids, especially unsaturated fatty acids (UFAs) and polyunsaturated fatty acids (PUFAs), progressively accumulated in the testes, highlighting their role in energy supply and membrane integrity during gametogenesis. Phosphorus (P) accumulated in parallel with fatty acids, supporting DNA and RNA synthesis, energy metabolism, and cell membrane function. This study emphasizes the crucial role of these biochemical components in supporting gonadal development in male M. coruscus, providing insights into the metabolic pathways involved in marine bivalve reproduction.

Coastal wetlands, known for their remarkable productivity and diverse ecological functions, face growing threats from aquaculture expansion, which can fragment natural habitats and disrupt water flow. In this study, we focused on White-bellied Sea-Eagles Haliaeetus leucogaster along the eastern coast of Odisha, India, to see how these top predators adapt to accelerating aquaculture. Across 22 nesting sites over three breeding seasons (2021–2024), we analysed 3,319 prey items, and found that fish dominated at 66.89%, followed by birds (25.64%), reptiles (3.31%), invertebrates (3.16%), and mammals (0.99%). Using generalised additive models (GAMs), we evaluated various landscape factors influencing the proportion of fish in WBSE diets. Our results revealed that shorter distances to natural water-bodies and higher water coverage strongly influenced higher fish intake, while aquaculture-related variables did not increase fish consumption. These patterns indicate that WBSEs favour wild fish in less-disturbed wetlands, likely because of better energy returns, lower risks, and convenient perching spots. Consequently, our findings highlight the need to safeguard natural aquatic habitats for sustaining apex predators and point to ways of reconciling aquaculture growth with wetland conservation. By clarifying how the eagles respond to changes in coastal landscapes, we offer key insights for preserving biodiversity under fast-paced environmental transformation.

The use of antibiotics in fish and shrimp aquaculture all over the world was found to be only partially successful in preventing infectious diseases. However, their overuse has resulted in the contamination of closed aquatic ecosystems, reduced antibiotic resistance in organisms that fight infectious diseases, and compromised the effectiveness of various antibiotic medications in controlling diseases. Excessive use of antibiotics damages aquaculture species and impacts human health, also rendering the most potent antibiotics increasingly ineffective, with limited alternatives. Therefore, intensive research efforts have been made to replace antibiotics with other protocols and methods like vaccines, phage therapy, quorum quenching technology, probiotics, prebiotics, chicken egg yolk antibody (IgY), and plant therapy,” etc. Though all these methods have great potential, many of them are still in the experimental stage, except for fish vaccines. All these alternative technologies need to be carefully standardized and evaluated before implementation. In recent times, after realizing the importance of the gut microbiome community in maintaining the health of animals, efforts have been made to use the microbiome strains for the prevention of pathogenic bacterial and viral infections. Now it has been experimentally proven that animals should possess a healthy microbiome community in their gut tract to strengthen the immune system and prevent the entry of harmful pathogens. Investigations are now being carried out on the derivation of various bioactive compounds from the gut microbiome strains and their structural profile and functionality using the molecular tools of metagenomics and bioinformatics. Such newly discovered compounds from microbiomes can be used as potential alternatives to replace antibiotic drugs in the aquaculture industry. These alternatives are likely to emerge as breakthroughs in animal health management and farming, with effects on cost efficiency, species health, productivity, and yield enhancement. Therefore, introducing new micro-innovative technologies into an overall health management plan will be highly beneficial.

There is increasing recognition that the welfare needs of cephalopod molluscs and decapod crustaceans are important. Current commercial practices involving these animals include a range of potential threats to their welfare, such as conditions of farming, capture, transport, and slaughter. This article draws from and updates our 2021 review for the UK Government, recommending a range of relatively simple and impactful changes that could benefit welfare while highlighting important research gaps that should be prioritised to facilitate the drafting of guidelines for best-practice.

Stocks of Pacific Bluefin tuna continue to decline to dangerous levels, with figures published in an International Scientific Committee report in April estimating that spawning stock levels are now less than three percent of their unfished levels. In line with international recommendations, Japan, which consumes 80 percent of the world's tuna, has implemented measures to counter the trend. However, some experts question their efficacy, and warn that, if current catch levels continue, Bluefin may well be a leading topic of discussion at the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) when members meet in Johannesburg later this year,.

Conservation aquaculture, defined as cultivating aquatic organisms to manage or replenish natural populations, has been advocated as a strategy to enhance fisheries production and help restore declining populations. Culture is especially compelling for species in steep decline and for which there is established methodology. The queen conch Aliger gigas is an example of a species with widely overexploited populations, with attempts to culture the species commercially ongoing for > 40 years. However, hatchery-releases have shown low survival from post-settlement to near maturity, leading to low conservation aquaculture potential. When this is viewed alongside large-scale fishery extractions, it is apparent that it is not commercially feasible to replace wild harvest nor ecologically feasible to replenish queen conch populations using existing aquaculture approaches. An age-based mortality model estimates the magnitude of culture required to replace a single adult of reproductive age. Extrapolations from catch–weight relationships highlight the scale of facilities and costs required to partially offset the harvest in a typical Caribbean fishery. Estimates of reproduction to achieve replacement suggest a greater yield from properly protecting natural breeding aggregations. Queen conch aquaculture is useful for scientific inquiry, community engagement and education, but not for stock enhancement or population restoration without more practical and cost-efficient options. Therefore, protecting breeding aggregations should be prioritized for the ecological viability of the species, as well as for its economic value for the people and industries that rely upon it.

A new species of Myxobolidae, Henneguya cardii n. sp., is described infecting the European seabass Dicentrarchus labrax, a fish of high commercial value intensively cultivated in southern Europe. Henneguya cardii n. sp. was found in the bulbus arteriosus and spleen with a prevalence of infection of 13.5%. In the heart, it forms irregular whitish plasmodia measuring 1 mm in size. Mature myxospores are broadly obovoid in frontal view and ellipsoidal in lateral view, with 2 equal caudal appendages. Polar capsules are ovoid and symmetric, with 3–4 polar tubule coils. Myxospores measure 10.2 ± 0.6 (8.8–11.6) μm in length, 8.0 ± 0.7 (5.3–8.8) μm in width and 5.6 ± 0.2 (5.1–6.4) μm in thickness. Caudal appendages are 36.6 ± 3.2 (27.4–42.9) μm long. Total spore length is 47.6 ± 3.2 (41.2–53.2) μm. Polar capsules measure 4.0 ± 0.2 (3.4–4.6) by 2.2 ± 0.1 (1.9–2.6) μm. Small subunit ribosomal RNA-based tree topologies position H. cardii n. sp. within a lineage of marine myxobolids that is mostly comprised of other Henneguya species. Host-relatedness is reinforced as the main evolutionary driver for myxobolids, with the positioning of H. cardii n. sp. further suggesting tissue tropism as another important evolutionary driver for marine heart infecting Henneguya. Nonetheless, the inner complexity of this lineage suggests that identification of the evolutionary patterns driving its phylogeny will require discovery of the true diversity of marine myxobolids.

We herein investigated the influence of temperature on the embryonic development (from fertilisation to hatching) of Mugil liza larvae. For this purpose, oocytes (>600 μm) and sperm were obtained from breeding stock at the laboratory of marine fish culture (LAPMAR). After fertilisation, 1200 eggs were distributed in 12 cylindrical experimental units of 400 mL under four different temperatures 18, 22, 26 and 30 ºC, all in triplicate. Every 15 min until hatching, about 10 eggs were randomly sampled in each treatment. The eggs were visualized and photographed, and the classification of embryonic stages was performed. Temperature influenced the main events of the embryonic development of M. liza. More accelerated development was observed according to the increase in temperature until the gastrula phase. At temperatures of 22 and 26 °C, embryonic development occurred from fertilisation to hatching of the larvae. In the 18 °C treatment, it was verified that most of the embryos ceased development during the final phase of cleavage and the beginning of blastula formation, while in the 30 °C treatment patterns of embryo malformation were also verified, with erratic divisions of the blastomeres, resulting in irregular cells. Unlike what was observed at a temperature of 18 °C, none of the embryos incubated at 30 °C reached the blastopore closure phase, stopping in the gastrula. The larvae hatched in the treatments at 22 and 26 °C were viable and exhibited intense swimming, with a large amount of reserve material (yolk) and an evident drop of oil.

We have developed probabilistic models to estimate the likelihood of harmful algae presence and outbreaks along the Norwegian coast, which can help optimization of the national monitoring program and the planning of mitigation actions. We employ support vector machines to calibrate probabilistic models for estimating the presence and harmful abundance (HA) of eight toxic algae found along the Norwegian coast, including Alexandrium spp., Alexandrium tamarense, Dinophysis acuta, Dinophysis acuminata, Dinophysis norvegica, Pseudo-nitzschia spp., Protoceratium reticulatum, and Azadinium spinosum. The inputs are sea surface temperature, photosynthetically active radiation, mixed layer depth, and sea surface salinity. The probabilistic models are trained with data from 2006 to 2013 and tested with data from 2014 to 2019. The presence models demonstrate good statistical performance across all taxa, with R (observed presence frequency vs. predicted probability) ranging from 0.69 to 0.98 and root mean squared error ranging from 0.84% to 7.84%. Predicting the probability of HA is more challenging, and the HA models only reach skill with four taxa (Alexandrium spp., A. tamarense, D. acuta, and A. spinosum). There are large differences in seasonal and geographical variability and sensitivity to the model input of different taxa, which are presented and discussed. The models estimate geographical regions and periods with relatively higher risk of toxic species presence and HA, and might optimize the harmful algae monitoring. The method can be extended to other regions as it relies only on remote sensing and model data as input and running national programs of toxic algae monitoring.