A wide range of fish species, as well as crustacean species, have been cultured in either fresh and/or marine water, and these cultured species may differ in different countries or different regions in the world. But these cultured species are consistently subjected to the threat of common, or their own specific, diseases caused by various pathogens during the process of aquaculture, including parasites, bacteria and viruses, which may cause vast mortalities and severe economic losses in these cultured species. Over the last few decades, various efforts have been devoted to the understanding of immune systems of cultured aquatic species, and to fathoming all possible mechanisms involved in molecular and ecological interactions between hosts and pathogens in order to develop effective measures and strategies for the maintenance of stock health, food security and sustainable aquaculture.

In this issue, two articles are related to the immune systems and their functions, and in particular one article proposes a fascinating and promising strategy for the development of vaccines to combat bacterial, as well as viral, diseases in fish.^1-3

Antimicrobial peptides (AMPs) are historically well-known effective immune molecules with various number of amino acids, and are produced through the recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs) on host cells.^{1, 4} In crustaceans, these cells are mainly classified as haemocytes, which exist in haemolymph of invertebrates.¹ Interestingly, in another review article published also in this issue, cells circulating in blood vessels of teleost fish, many of which are aquaculture species in the world, are reviewed in terms of their phagocytic functions.²

Starting from the brief introduction of the initial identification of two AMPs in haemolymph of brachyuran crabs, Matos and Rosa,¹ using a feasible combination of clearly illustrated figures and accurately expressed text, analysed the composition of AMPs in different taxa of crustaceans, and identified chronologically major steps in the identification and possible functional characterization of AMPs in crustaceans. It may be of theoretical and applicable to see the focused presentation on various aspects of penaeid shrimp AMPs, including crustins, anti-lipopolysaccharide factors (ALFs), penaeidins and stylicins. Of course, many other AMPs reported in crustacean in literature have been reviewed in this article.¹

In addition to the antimicrobial function, the possible immune regulating roles of AMPs are summarized in this review¹; and as in other review articles, future perspectives are also proposed in this review. But a scientifically valuable and novel point proposed in this review would be the bioinformatic and functional identification of nucleotide polymorphism and gene copy number variation of AMPs, which may have a theoretical and applied value for the improvement of antimicrobial function in crustaceans and for the selection of disease-resistant animals.

It would be uncommon for aquaculturists to know the existence of the so-called professional and non-professional phagocytes in blood of teleost fish, which can all phagocytose foreign microorganisms and abnormal cells. In fact, classically clarified blood cells reported in higher vertebrates, including erythrocytes, thrombocytes, lymphocytes, monocytes/macrophages and neutrophils, are also present in blood of teleost fish, a group of primary lineage of vertebrates. In brief, professional phagocytes in blood include monocytes, macrophages and neutrophils, and non-professional phagocytes include thrombocytes, B cells in fish. No matter whether blood cells in fish are separated as either professional or non-professional phagocytes, they all have phagocytosis activity, as summarized in this review article.²

Further, Zhu and Su summarize many other functions of fish peripheral blood cells, in addition to their phagocytic functions.² It would be interesting to mention that, as described in the review, B cells in fish have roles in antigen presentation, as well as in antibody production as in mammals. The authors finally point out future directions on the research of phagocytic mechanisms in different types of blood cells, which may have importance in comparative immunology and in the development of fish health management strategy.

To maintain the fish health and/or to control disease outbreaks, antibiotics have at least to some extent been applied in aquaculture, which has caused wide concerns over food safety of aquaculture products, and also resulted in antimicrobial resistance of pathogenic bacteria and viruses.³ Barnes et al.,³ in their review article, propose to develop autogenous vaccination to combat antimicrobial resistance in aquaculture.³ Autogenous vaccines are defined as custom vaccines produced from pathogens isolated directly from affected farms, and used locally in these farms. Importantly, the evidence cited in this review article has shown that the use of such autogenous vaccines is effective in animal husbandry.

Barnes et al.³ analyse the pathway towards the success of vaccine application in salmon production in Norway in comparison with the antibiotic use in Chile also in salmon production. They further examine cultured species diversity, diseases, pathogen genetic variations in a few countries, such as Indonesia, Vietnam and Thailand, and concluded that autogenous vaccines have advantages in many low- and middle-income countries in terms of intellectual property, efficacy and flexibility. The possible technical, bureaucratic and infrastructural issues are identified for the implementation of these autogenous vaccines in aquaculture. It is believed that a local fish disease prevention solution would have a wide and even global significance in combatting antimicrobial resistance.

在淡水和/或海水中养殖了种类繁多的鱼类以及甲壳类动物，这些养殖的物种在世界不同国家或不同地区可能有所不同。但这些养殖物种在水产养殖过程中始终受到由寄生虫、细菌和病毒等各种病原体引起的常见或自身特定疾病的威胁，这可能导致这些养殖物种大量死亡和严重的经济损失。在过去的几十年中，人们致力于了解养殖水生物种的免疫系统，并探索宿主与病原体之间分子和生态相互作用的所有可能机制，以制定有效的措施和策略来维持水生物种的免疫系统。股票健康，

在本期中，有两篇文章与免疫系统及其功能有关，其中一篇文章特别提出了一种引人入胜且有前景的策略来开发疫苗来对抗鱼类的细菌和病毒疾病。^1-3

抗菌肽 (AMPs) 是历史上众所周知的有效免疫分子，具有不同数量的氨基酸，是通过宿主细胞上的模式识别受体 (PRR) 识别病原体相关分子模式 (PAMPs) 产生的。^{1, 4}在甲壳类动物中，这些细胞主要归类为血细胞，存在于无脊椎动物的血淋巴中。¹有趣的是，在本期也发表的另一篇评论文章中，对硬骨鱼血管中循环的细胞（其中许多是世界上的水产养殖物种）的吞噬功能进行了综述。²

从简要介绍了短尾蟹血淋巴中两种 AMPs 的初步鉴定开始，Matos 和 Rosa ¹使用清晰插图和准确表达的文字的可行组合，分析了甲壳类动物不同分类群中 AMPs 的组成，并按时间顺序鉴定甲壳类动物中 AMP 的鉴定和可能的功能表征的主要步骤。看到对虾 AMP 的各个方面的重点介绍可能具有理论性和适用性，包括硬皮素、抗脂多糖因子 (ALF)、对虾素和 stylicins。当然，本文还回顾了文献中甲壳类动物中报道的许多其他 AMP。¹

除了抗菌功能外，本综述还总结了 AMPs 可能的免疫调节作用¹；和其他评论文章一样，这篇评论也提出了未来的观点。但本综述提出的一个具有科学价值和新颖性的观点是AMPs核苷酸多态性和基因拷贝数变异的生物信息学和功能鉴定，这可能对甲壳类动物抗菌功能的提高和甲壳类抗生素的选择具有理论和应用价值。抗病动物。

鲜有养殖者知道硬骨鱼血液中存在所谓的专业和非专业吞噬细胞，它们都可以吞噬外来微生物和异常细胞。事实上，在高等脊椎动物中报道的经典澄清的血细胞，包括红细胞、血小板、淋巴细胞、单核细胞/巨噬细胞和中性粒细胞，也存在于硬骨鱼的血液中，这是一组脊椎动物的初级谱系。简而言之，血液中的专业吞噬细胞包括单核细胞、巨噬细胞和中性粒细胞，非专业吞噬细胞包括鱼类中的血小板、B细胞。正如这篇综述文章所总结的那样，无论鱼类中的血细胞被分为专业吞噬细胞还是非专业吞噬细胞，它们都具有吞噬作用。²

此外，朱和苏总结了鱼类外周血细胞的许多其他功能，除了它们的吞噬功能。²值得一提的是，正如评论中所描述的，鱼类中的 B 细胞在抗原呈递以及在哺乳动物中产生抗体方面发挥作用。作者最后指出了不同类型血细胞吞噬机制研究的未来方向，这可能对比较免疫学和鱼类健康管理策略的制定具有重要意义。

为了维持鱼类健康和/或控制疾病爆发，水产养殖中至少在一定程度上应用了抗生素，这引起了人们对水产养殖产品食品安全的广泛关注，同时也导致了病原菌和病毒的抗菌素耐药性。³ Barnes 等人³在他们的评论文章中建议开发自体疫苗以对抗水产养殖中的抗菌素耐药性。³自体疫苗被定义为由直接从受影响农场分离的病原体生产的定制疫苗，并在这些农场当地使用。重要的是，这篇评论文章中引用的证据表明，使用此类自体疫苗在畜牧业中是有效的。

巴恩斯等人。³分析了挪威在鲑鱼生产中成功应用疫苗的途径，并与智利在鲑鱼生产中的抗生素使用进行了比较。他们进一步研究了印度尼西亚、越南和泰国等少数国家的养殖物种多样性、疾病、病原体遗传变异，并得出结论认为，自体疫苗在知识产权、功效和灵活性方面在许多中低收入国家具有优势。 . 确定了在水产养殖中实施这些自体疫苗可能存在的技术、官僚和基础设施问题。人们相信，当地的鱼类疾病预防解决方案将在对抗抗菌素耐药性方面具有广泛甚至全球意义。