Nucleic acid technologies in crustacean disease management: Diagnostics, therapeutics, and surveillance.

Crustacean aquaculture, particularly shrimp, crab, and lobster production, contributes around US$10 billion annually to the global food supply but remains highly vulnerable to viral and bacterial diseases. Pathogens such as White Spot Syndrome Virus (WSSV), Yellow Head Virus (YHV), Taura Syndrome Virus (TSV), and Vibrio species continue to cause substantial economic losses, and conventional management based on visual inspection, histopathology, and antimicrobial treatment is often slow and insensitive. This review examines how nucleic acid technologies are reshaping diagnostics, therapeutics, and surveillance in crustacean health management. Molecular diagnostic platforms including PCR, quantitative PCR, reverse transcription PCR, loop mediated isothermal amplification, recombinase polymerase amplification, and multiplex assays allow rapid, sensitive, and specific detection of pathogens, often before clinical signs appear. RNA interference shows strong therapeutic promise against viral pathogens, with experimental studies reporting 40 to 80% reductions in cumulative mortality, although stability, dosing, delivery, and production cost continue to limit commercial use. CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and Cas (CRISPR-associated) has emerged as a powerful platform for functional genomics, immune gene characterisation, and the future development of disease resistant strains, though application in crustaceans remains largely proof of concept. Environmental DNA and molecular biosurveillance enable early pathogen detection through water and sediment sampling, supporting proactive biosecurity and precision aquaculture. Persistent barriers include scalability, infrastructure gaps in producing regions, regulatory uncertainty, and public acceptance. Future progress will rely on improved delivery systems, expanded crustacean genomic resources, and integration of molecular tools with digital farm management to deliver sustainable disease control.