In this issue:

• Ornamental Aquaculture Field School: A new extension approach
• State of the art of carp spawn production and transportation at Ramsagar, Bankura District, West Bengal, India
• Seahorse aquaculture: A new paradigm of commercial activity
• Mixed infections in tropical freshwater fish culture systems: A potential emerging threat for successful aquaculture
• NACA Newsletter

The aquatic environment contains many opportunistic pathogens and fish are frequently infected by a range of parasites, bacteria, viruses, and fungi. In most incidences of disease, the involvement of two or more pathogens are often seen, which in turn complicates diagnosis and treatment. Here we present a few case studies on mixed infections in aquaculture systems, which may become more common in future due to changing climatic patterns and associated adverse impacts on water quality. Mixed infections seem to be a big challenge to diagnostic laboratories and health specialists in terms of providing a correct diagnosis and treatment.

Seahorses are charismatic livebearers that come under the genus Hippocampus spp. Seahorses are widely distributed in tropical and temperate waters (mostly in the Indo-Pacific region) and different species can tolerate a salinity range of 6-35 ppt.

Seahorses are highly in demand for traditional medicines and curio trade purposes in the dried form and live ones are popular in the marine ornamental aquarium trade. As a result, they are vulnerable to overfishing. Since over-exploitation of these charismatic species has resulted in a drastic reduction in their natural populations, aquaculture of seahorses on a commercial scale may help to reduce pressure on wild stocks. This article provides an overview of seahorse aquaculture in India including research, the production cycle, production systems, and disease issues.

For the last five decades or so, West Bengal has been the leading state in India for the production of production and supply of major carp fry, underpinning the success of freshwater fish culture. This article describes the structure of the hatchery industry in Ramsagar, West Bengal, production practices and systems, packing, transport and links to major seed markets both within the state and elsewhere in India. Market price, broodstock management and natural breeding methods are also discussed.

The Farmer Field School approach is promoted by FAO as an alternative technology dissemination mechanism to the top-down extension methods in south-east Asian countries. In order to utilise the potential of the farmer field school approach for aquaculture, ICAR-CIFA has piloted Aquaculture Field Schools (AFS) in several states in India. AFS are schools without walls to improve the decision-making capacity of the farmers and facilitate cross-learning opportunities. It is a participatory extension methodology whereby fish farmers are allowed to choose the methods of aquaculture production through discovery-based approaches. 

To assist shrimp pathologists worldwide we are providing here photomicrographs of unique basophilic inclusions that are produced by Wenzhou shrimp virus 8 (WZV8),  discovered in 2015 by Li et. al. We designed PCR primers and in situ hybridization probes for detection of WZV8. Subsequent ISH assays with shrimp RT-PCR positive for WZV8 samples indicate unique inclusions described herein as linked to WZV8 in H&E stained tissues. Going back over our previous histological reports and archived slides, we have found the unique WZV8 inclusions in E-cells of normal shrimp samples from several shrimp farming countries in Austral-Asia since at least 2008, and more recently in samples of P. vannamei from the Americas. We urge shrimp pathologists to review their records and specimens for the presence of WZV8 E-cell inclusions described herein to provide data on the global prevalence and impact of WZV8-like infections.

The Fish Health Section of the Asian Fisheries Society is inviting you to a Zoom Webinar on Viral Diseases of Aquatic Animals, 1 June at 13:00 Bangkok time (GMT +7).

Participation is free but advance registration is required.

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 2021 and the original and updated reports can be accessed from the QAAD page.

This report summaries the proceedings of the 20th meeting of the Regional Advisory Group on Aquatic Animal Health, held 4-5 November 2021. The meeting discussed: Progress on NACA’s Asia Regional Aquatic Animal Health Program; updates from the OIE Aquatic Animal Health Standards Commission; aquaculture biosecurity; Progressive Management Pathway for Improving Aquaculture Biosecurity activities relevant to Asia; a systematic approach for quantifying biosecurity measures in aquaculture; aquatic animal health strategy; updates on the OIE Regional Collaboration Framework on Aquatic Animal Health; and updates on the QAAD Reporting and Disease List.

Annual consumption of Artemia is now estimated at 3,500 – 4,000 tonnes, underpinning the production of over 900 billion crustacean post larvae and fish fry. With approximately 90 percent of the current Artemia production harvested from inland salt lakes, the future of the hatchery industry could be at risk and requires urgent attention. The purpose of the workshop was to explore needs and opportunities for a new international initiative to guarantee a more sustainable provision of Artemia, both from natural sources and from controlled extractive Artemia farming integrated with salt production and other fish/crustacean aquaculture.