Genome editing and silencing techniques can transform the biology that we understand, diseases affecting fish and other aquatic animals. Gene editing is now being tested in aquaculture, reproduction control, sterility, and disease resistance aspects. More money must be invested in innovative technology to solve these issues in this industry. So gene silencing and genomic DNA editing have the potential significant impact on aquatic animal treatment in the future. Genome editing in fish is an interested part of research that has the potential to revolutionize aquaculture and aid in the understanding of genetic diseases in fish. Genome editing has many applications in editing the genome of fish species for various uses; zinc finger nucleases (ZFNs) were used to experts and follow ethical and regulatory guidelines when conducting fish genome editing disrupt genes in zebrafish (Danio rerio) both somatically and germinally. On the other side, these genetic modification techniques can cause various negative effects through multiple mutations; by that process, it’s challenging to recognise the genetically modified organisms. Genome editing in fish is a complex field requiring specialized knowledge and expertise. It is always advisable to consult with experiments.

In the present study, the DNA barcoding of the nematode parasite infecting Ompok bimaculatus and Nemacheilus anguilla fish species was carried out in Barvi Reservoir, Maharashtra. To ascertain the taxonomic status of these nematode parasites, an 18S gene marker was used. Accurate identification of fish parasites is essential to formulate preventive strategies and to study host–environment relations. The present study did barcoding of the nematode parasites of the fishes caught from the Barvi Reservoir using the nuclear 18S rDNA (SSU) sequence. The nuclear 18S rDNA (SSU) was amplified into two overlapping amplicons and sequenced to identify the species based on the sequence similarity with the NCBI GenBank database. The present study sequences (both fragments) showed 98% similarity with the species of Eustrongylides. The average genetic distance value between the present study sample and species of Eustrongylides was 0.003. In the phylogenetic tree also, the sequence was clustered with the species of Eustrongylides with significant bootstrap values. The present study identified the nematode parasite of the fish caught from the Barvi Reservoir, as species of Eustrongylides. The species‐level identification could not be possible due to the insufficient/lack of reference sequences in the database. It indicates the knowledge gap concerning the species‐specific molecular markers for nematode parasites of the fish.

The potential applications of fish muscle cell lines in aquaculture, biotechnology, and muscle biology have garnered significant attention in recent years. Fish muscle cells are useful for studying muscle growth, development, and regeneration because they provide valuable insights into the mechanisms underlying muscle function. Recent advancements in establishing and characterizing fish muscle cell lines have provided a deeper understanding of muscle fiber differentiation, hypertrophy, and the effects of various environmental and genetic factors. Furthermore, the use of fish muscle cell lines has facilitated research into the molecular pathways regulating muscle plasticity, metabolic processes, and responses to stressors, such as temperature fluctuations and hypoxia. This review presents a comprehensive overview of the current advances in the development of fish muscle cell lines, highlighting recent breakthroughs in genetic manipulation, in vitro culture techniques, and their use in muscle physiology studies. It also discusses the emerging applications of fish muscle cells in aquaculture, therapeutic drug testing, and tissue engineering, as well as the challenges and future directions in the field. Understanding these advancements will enhance aquaculture sustainability and offer new strategies for improving fish muscle health and growth.

Fish possess a unique immune system that, while somewhat similar to mammals, exhibits distinct characteristics. This review paper explains the complexities of fish immunity, highlighting the innate and adaptive immune responses that protect against various pathogens, including bacteria (Aeromonas spp, Flavobacterium columnare, Mycobacterium marinum, Streptococcus iniae, Edwardsiella tarda, Pseudomonas aeruginosa etc), viruses (Infectious Hematopoietic Necrosis Virus (IHNV), Viral Hemorrhagic Septicemia Virus (VHSV) etc.), fungi and parasites (Dioctophyma renale etc). Host-pathogen interactions are dynamic and critical for understanding the immune evasion strategies employed by pathogens, such as antigenic variation, molecular mimicry and biofilm formation. Vaccination is crucial in aquaculture, enhancing fish immunity against diseases through various vaccines, including inactivated, live, subunit, and nucleic acid vaccines. Various delivery methods are employed to maximize immunogenic responses, such as injection, immersion, and oral administration. Additionally, advancements in science and technology have led to innovative techniques to increase vaccine efficacy, including nanoparticle delivery and microencapsulation. Successful vaccination strategies have been adapted to combat significant fish pathogens, demonstrating the potential for enhancing disease resistance in aquaculture. This comprehensive overview underscores the importance of understanding fish immune systems and developing effective vaccination strategies to ensure fish health and sustainability in aquaculture practices.

Since sequencing was developed by Sanger and Gilbert in 1977, various sequencing methods have been introduced in biotechnology to sequence DNA. Next-generation sequencing is a novel high-tech method where the sequencing of thousands of DNA molecules can be done in parallel to generate enormous amounts of genetic data within one experiment. This novel generation of sequencing superseded conventional techniques like Sanger sequencing with parallelization to achieve rapid genome sequencing at minimum costs. In this chapter, we highlighted various applications of using NGS in different fields, such as genomic research, clinical diagnostics, metagenomics, water quality assessment, and food authenticity. Besides, NGS could identify genetic variations, diagnose diseases, and assess food quality with high accuracy, rapidity, and specificity.

Labeo rohita, commonly known as rohu, is a freshwater fish from the Cyprinidae family. Myostatin (MSTN), a member of the Transforming Growth Factor-β (TGF-β) superfamily, is a negative regulator of skeletal muscle growth. CRISPR-Cas9 has progressively enhanced genome-editing efficacy by targeting various sites in the genome. The dorsal muscle cell line developed from L. rohita, named LRDM, was maintained in L-15 media containing 5% FBS and cultured for up to 35 passages. Cells were cryopreserved at different passages, achieving a 50–70% revival efficiency. PAX7 and MYOD protein expression were assessed in the LRDM to confirm the myogenic capacity at the 10th, 20th, and 30th passages. PAX7 expression was prominent in early passages, while MYOD expression became more noticeable in later passages. Guide RNAs were designed to target the L. rohita MSTN gene. One-step digestion and ligation were performed by ligating the annealed oligos to the T7cas9sgRNA2 vector. The isolated plasmid containing the target sequence was validated by using Sanger sequencing. The gRNA plasmid and pT3TS-nls-zCas9-nls (pT3 Cas9) vector were digested by using the BamHI and XbaI restriction enzymes. The expected size bands were observed at ∼2541 and ∼7332 bp. In vitro transcription of the gRNA and synthesis of pT3 Cas9 were carried out using MEGAshortscript T7 and mMESSAGE mMACHINE T3 kits, respectively. Establishing a myostatin-knockout fish muscle cell line could serve as a valuable model for studying the molecular mechanisms underlying muscle development, including cultivated fish meat production, which will be pivotal for the scientific and technological advancements needed to advance cellular aquaculture.