Reviews in Aquaculture最新文献

To meet growing fish demand, aquaculture must develop sustainable, cost-effective, and high-performance fish feed formulations for industry advancement. Plant-based lipids are a viable alternative to forage fish ingredients in finfish diets. However, most plant-derived lipids lack long-chain polyunsaturated fatty acids (LC-PUFA) like EPA and DHA, which are nutritionally essential for fish. This review summarizes recent findings on the nutritional aspects of fish brood stock and sperm quality, emphasizing the effects of fatty acids on reproductive outcomes. Studies indicate that substituting fish oil with plant oils alters the fatty acid profiles in fish tissues and gametes, potentially compromising sperm quality, cryopreservation success, and progeny viability. Sperm membrane lipids, including EPA, DHA, and ARA, are vital for motility and fertilization rates post-thaw. Additionally, cryopreservation has been linked to molecular and epigenetic alterations in sperm, which may negatively affect offspring quality. The role of mRNA and noncoding RNA in regulating sperm function and embryonic development is well known, and thus any damage to these molecules as a consequence of cryopreservation might induce long-term effects on offspring. Proteomic analyses reveal that cryopreservation can lead to significant protein loss in sperm, diminishing their functional and fertilization capabilities. Optimizing cryoprotectant protocols and freezing techniques is crucial to reduce damage, while dietary fatty acids play a key role in preserving sperm quality during cryopreservation stress. Further research with omic technologies is crucial to fully understand sperm tolerance to cryopreservation, which will improve reproductive outcomes and enhance sustainability and quality in aquaculture.

The use of passive acoustic monitoring (PAM) has recently been integrated with other noninvasive ethological methodologies to enhance the understanding of shrimp feeding behaviour, as their mandibles emit click sounds during food intake. This review aims to compile recent advances and various applications of PAM in assessing shrimp feeding behaviour under controlled laboratory and farm conditions. It includes a description of key concepts, terms and general methodologies in the field of bioacoustics to facilitate understanding of acoustic characterisation, specific methodologies and the main uses of PAM in shrimp research. Among the primary contributions of PAM in laboratory studies are acoustic characterisation of clicks and mandibular structures associated with their emission for different species; variations in acoustic click parameters related to animal size, feed texture and pellet size; and effects on feeding behaviour caused by shrimp size, stocking density and specific characteristics of artificial diets (texture, formulations, additives and pellet sizes). Finally, future perspectives and recommendations for laboratory studies using PAM are provided. The review highlights the contribution of PAM, which, allied with other ethological methodologies, emerges as a novel tool for researching shrimp behaviour and optimising feed management in aquaculture.

Research efforts around the world have focused on identifying the occurrence of emerging contaminants in aquaculture areas. In the Brazilian context, studies have aimed to identify emerging contaminants in water used for this activity. This systematic review covered studies published without a specific time frame with the following criteria: research conducted in aquaculture areas or with species and cultured water in Brazil and analysis of emerging contaminants. Out of the 42 studies identified, 132 emerging contaminants were observed. The Southeast and South regions accounted for most of these studies, with limited research conducted in the North and Northeast regions. Tilapia was the most studied species, followed by mollusks. In toxicity tests, animals showed several effects, such as decreased oxygen consumption and swimming patterns, histopathological changes, inhibition of sperm production, cardiac edema, spinal deformity, and antimicrobial resistance. In conclusion, advancements in research on emerging contaminants in Brazilian aquaculture are needed as the number of existing studies is lower compared to global numbers. Few studies have focused on analyzing cultivation sites to identify the contaminants present and their sources. Also noteworthy is the scarcity of work in the Northern region of Brazil and on native species. Characterizing these environments in terms of the types of contaminants and main sources of contamination is essential to finding ways to mitigate ecological and human health risks, as well as developing specific legislation for these contaminants because they are currently not part of routine monitoring programs and are therefore not regulated, especially in aquaculture environments.

Aquatic invertebrates account for more than 33.4% of global aquaculture production and are important aquaculture animals worldwide. Although the frequent outbreaks of diseases and the lack of disease prevention strategies have greatly hindered further development of the invertebrate aquaculture industry. Immune priming is a phenomenon that invertebrates mount a faster and stronger secondary response than that of the primary response when encountered with a given microbe. It has been demonstrated to be present in a wide range of aquaculture species and would provide a fresh idea for disease prevention. As the main executors of immune defense in invertebrates, the circulating hemocytes are short-lived, and the solution for the paradox of keeping a long-lasting immune protection might lie in the formation of long-lived memory cells in immune priming. As a reference for the access of memory cell formation processes in aquaculture invertebrates, the cellular kinetics including expansion, contraction, and memory formation of lymphocytes in the adaptive immunity of vertebrates are discussed. Then the features of hemocytes in aquaculture invertebrates, and their kinetic changes of cell number and immune capacity during immune priming are summarized for the knowledge of a stronger secondary immune response. The regulatory roles of epigenetic modification and metabolic reprogramming in immune priming and their possible functions in memory cell formation and identification are proposed to be preferentially investigated for further clarifying the mechanism of immune priming, which might provide a novel entrance for understanding the mechanisms of immune priming and developing disease prevention strategy in aquaculture invertebrates.

Biofloc technology (BFT), initially adapted for shrimp farming in the 1970s, represents a sophisticated ecosystem of microorganisms designed to enhance aquaculture productivity and sustainability. Despite its established history, research into BFT is surprisingly still at an early stage globally. This review conducted a bibliometric analysis of 612 articles from major aquaculture journals spanning 2008–2023 to systematically explore the development, trends, and focal points of BFT research. The analysis revealed that the bulk of significant contributions originates from Brazil and China, and highlighting areas of interest can be categorized into four hotspots, such as (1) efficient nitrogen transformation, (2) biofloc microbiology, (3) biofloc's immunostimulant properties, and (4) the evaluation of research methodologies. At the end, the microecology concept was introduced, and the cross-discipline methods were promoted in the aquaculture field. Notably, much of the BFT research is still at an exploratory phase, with numerous functional bacteria unidentified and optimization strategies for BFT underdeveloped. These gaps present opportunities for enhancing aquaculture through improvements in wastewater management, product quality, safety, and yield. Furthermore, the review notes a growing trend in applying microbiome research and microecological analysis in aquaculture, with high-throughput sequencing data increasingly used to understand microbial interactions and nitrogen transformation within bioflocs. This direction promises to unlock further insights into the complex microbial ecosystems of bioflocs and their applications in sustainable aquaculture.

Global fish production exceeds 170 million tons in 2023, and provides a high-quality protein source for humans. However, various factors may contribute to hypoxic stress and anemia, which contribute to yield loss in fish production. Elevated red blood cell counts or activation of erythropoiesis are well-known responses to anemia and hypoxia stress in fish. Erythropoiesis is the process of formation of new erythrocytes, from hemopoietic stem cells, through the differentiation of erythroblasts, to the maturation of red blood cells. This step-wise process is governed by complex transcriptional, post-translational, and epigenetic programs in response to extracellular signals. This review summarizes developing knowledge regarding erythropoiesis in teleosts, including the wave and site of erythropoiesis, specification of the erythroid lineage, and molecular regulation mechanisms. A summary of research gaps is presented, to be addressed by future research on teleosts. Understanding erythropoiesis facilitates improved fish husbandry and selective breeding of hypoxia-tolerance fish, to ultimately contribute to increased production.

Diatoms and bacteria have coexisted and coevolved for more than 200 million years, and their interactions have driven the processes of underlying major biogeochemical cycles. These complex and heterogeneous interactions span the range from synergistic to competitive and antagonistic, and they are regulated by diverse metabolites and biochemical mediators. Despite the significance of diatom–bacterial interactions in shaping aquatic food webs, driving nutrient cycles, and controlling algal blooms, the field currently lacks a comprehensive review of the current literature, research contents, and future research trends and perspectives. This review presents a comprehensive analysis of diatom–bacterial interactions by summarizing the information from current publications, including temporal trends, the most productive authors, journals, and countries, and illustrating current research contents, including regions, methods, foci, the interaction mechanisms and the environmental regulation. In addition, we discuss future research trends and perspectives. Our results indicate that most of the current research has been conducted in the ocean, using the methods of co-culture experiments or field investigation combined with high-throughput sequencing. The current research foci include the mechanisms of multiple cell-to-cell synergistic, competitive, antagonistic interactions, and multiple interactions regulated by biochemical molecules, and potential biotechnological applications. Furthermore, the future trends in this research field concern the underlying mechanisms of variation in diatom–bacterial interactions influenced by environmental changes and the possible applications. This review provides a comprehensive perspective on diatom-bacterial relationships as well as a guide to future research.