This manual covers everything from grass carp's natural distribution and reproductive behaviours to its biology and anatomy. This manual also explores diseases that can affect grass carp and emphasises the crucial connection between animal welfare and stress in fish. With a detailed discussion on cultivation systems, this manual includes pond structures and fish farming techniques in both polyculture and monoculture. It provides practical insights into important aspects such as water quality monitoring, feeding, nutrition, health checks and behaviour assessments at every stage of grass carp farming – from broodstock management to pre-slaughter and slaughter processes. The emphasis is on responsible harvesting techniques, transportation considerations and humane slaughter methods. This manual offers a comprehensive guide for both novice and experienced fish farmers, and enthusiasts interested in cultivating grass carp sustainably and ensuring optimal animal welfare.

This FAO publication on brine shrimp is a manual for all those who are using Artemia or have an interest in this organism, whether as a source of live food in the hatchery, as a model organism in research, or for other purpose. It is intended for those who wish to update their knowledge on its biology, production or its use, but also for those who want to learn about Artemia for the first time. This manual presents in a concise form essential information on Artemia biology and the most important natural cyst resources that find their way to the aquaculture market. It also provides detailed information on general principles and practical procedures to produce Artemia in ponds and in tank systems. Finally, the manual offers a compilation of state-of-the-art guidelines and methodologies related to the use of this crucial live food organism in aquaculture.

With the implementation of the new aquatic animal disease reporting in the Asia Pacific region from January 2021, and in lieu of the published QAAD Reports (last issue published was 4^th quarter of 2020), NACA is publishing reported aquatic animal diseases submitted by countries in the Asia-Pacific region. This report covers the fourth quarter of 2023 and the original and updated reports can be accessed from the QAAD page.

In this issue:

• 33rd NACA Governing Council held in New Delhi, India.
• Dr Eduardo Leaño elected as next Director General of NACA.
• Reported aquatic animal diseases in the Asia-Pacific region during the third quarter of 2023.
• We are hiring: Professional Associate, aquaculture transformation.

This report summarises the proceedings of the 22nd meeting of the Regional Advisory Group on Aquatic Animal Health, held 6-7 November 2023. The role of the group is to review trends in disease and emerging threats in the region, identify developments in global disease issues and standards, to evaluate the Quarterly Aquatic Animal Disease Reporting Program and to provide guidance on regional strategies to improve aquatic animal health management. The meeting discussed Progress on NACA’s Asia Regional Aquatic Animal Health Programme; Farm-level aquaculture biosecurity: From a tilapia parasites perspectives; Farm level aquaculture biosecurity: Update on Operation Black Tiger Shrimp Revival; Update on WOAH Asia-Pacific Network on Aquatic Animal Health; Update on regional disease reporting and disease list.

Quality biological sampling is a fundamental requirement for all kinds of work on diagnosing diseases and screening for pathogens. Fish sampling requires specific techniques and skills to collect good biological samples for accurate disease diagnosis. This package of practices developed by WorldFish and partners provides advice on fish sampling protocols for routine disease diagnostics and outbreak investigations in tilapia, carp and catfish production systems. These sampling protocols provide guidance and training to project team members, researchers, resident veterinarians, extension officers and farmers tasked with collecting quality biological samples for laboratory diagnosis whenever disease outbreaks occur on farms or hatcheries. A free online introductory course on fish sampling for disease diagnostics is also available via Learn.ink.

Infectious diseases represent one of the major challenges and limitation to sustainable aquaculture. They can have major impacts on animal welfare, livelihood of farmers and threaten the health of captive stocks and wild populations. Pathogens can spread through movement of live fish, fish products, water and shared equipment. Routine screenings of pathogens in aquatic animal production systems are important to minimize the risk of their introduction, transmission and spread. On suspicion of a disease during abnormal mortalities, investigation with collection of biological samples from moribund animals must take place rapidly for disease diagnostics. Quality biological sampling is a fundamental requirement for all kinds of disease diagnostic and pathogen screening work. WorldFish and partners developed this rapid guide on sampling materials required for fish disease diagnostics. It lists all the personal protective equipment, the data collection/recording/cleaning supplies and sampling materials: consumables, reagents, media and tools needed to conduct one of the six quick fish sampling guides for disease diagnostics: 1. Wet-mount sampling guide (for ectoparasites & fungi) 2. Fish & water Microbiome sampling guide 3. Blood sampling guide 4. Bacteriology sampling guide 5. Molecular and virology sampling guide 6. Histology sampling guide.

A free online course on foundations in fish disease sampling is also available via Learn.ink.

Parasitic and fungal infestations represent one of the major challenges to sustainable aquaculture. As part of routine health checks or during abnormal mortality events, screening for ectoparasites and fungi in tilapia, carp and catfish production systems is important to minimize the risk of their introduction, transmission and spread. WorldFish and partners developed this quick guide for ectoparasites and fungi assessment under a light compound microscope. Standard wet-mount specimens consist of gill biopsy (gill clip), fin biopsy (fin clip) and skin scraping (mucus smears). Additional smears may be included in the presence of external lesions/ulcers (eye, skin, mouth). A free online training course on wet mount sampling is also available via Learn.ink.

Interactions between microbes associated with the host, other organisms present in the system and the environment itself are increasingly recognised to contribute to aquatic animal diseases. Those microbiome assemblages and their functions are extremely diverse and poorly understood. They vary over time in water and between host tissues and organs.

High-throughput sequencing technologies (multi-omics) and bioinformatics analysis of complex microbiomes can provide biological insights offering new opportunities for early detection of pathogens and disease mitigation strategies. Similarly, such approaches are being applied to study the effect of locally available ingredients for use in fish feeds and their impact on fist gut microbiome and the health of the pond environment—optimising the growing conditions on-farm.

WorldFish and partners developed this quick guide for microbiome sampling from fish skin/gills mucus swabs, internal organs (e.g. gut) and water samples from ponds, hatcheries tanks, river, and canals.

A free online training course on microbiome sampling is also available on Learn.ink.

Fish blood sampling requires specific techniques and skills that are fundamental for all kinds of analyses such as haematology, chemistry analysis, parasitology/bacteriology investigation, antibody titration, molecular diagnostic and many others. WorldFish and partners developed this quick guide on blood sampling from fish for: (1) blood serum isolation, (2) blood plasma isolation, (3) blood DNA extraction, (4) blood RNA extraction, or for (4) blood smear preparation on microscope slide. A free online course on blood sampling is also available via Learn.ink.