Aquaculture Asia Magazine, July-September 2018

In the ornamental fish markets of India, the euryhaline spotted scat Scatophagus argus and pearlspot Etroplus suratensis are popularly sold as ornamental fish. This article describes the nursing of wild-caught spotted scat seed and in-pond breeding of pearlspot to produce marketable sized fish at the Joykrishna hatchery and fish seed farm, located in the Hooghly River estuarine zone in coastal West Bengal, India. The fish are reared in brackishwater ponds for commercial utilisation as ornamental fish, supplying Hyderabad and other cities.

Makhana, Euryale ferox is a perennial aquatic herb with gigantic floating leaves that grows in still, shallow water. The sowing and harvesting of makhana seeds, a casual food for rural folk, is conducted by groups of migratory people belonging to the Mallah or Sahini community of Bihar. The makhana seeds are usually fallen and scattered over the bottom of the wetlands (beels) and must be collected manually by diving during September-November. The raw seeds sell for Rs. 60-70 per kg in Assam.

India’s share of the international ornamental fish trade is marginal but has been able to show consistent growth over the years. Of the total ornamental fishes traded by India, approximately 85% are native fishes sourced from the Western Ghats and North East India. The aquaculture of native fishes in seasonal water bodies can play a role in both conservation and generation of livelihoods. Imparting knowledge regarding ornamental fish trade and establishing market linkages is required to further develop the industry.

The use of sludge or ‘tubifex’ worm, Tubifex tubifex, as a live food for juvenile fish has been long practiced in farmers’ fields and it is an important fish food for spawn rearing. The cost of tubifex worm becomes prohibitive in the dry season, when supplies are limited. We conducted trials to test the feasibility of culturing tubifex using a selection of agro-industrial wastes. Net biomass production was highest using rice mill sludge as a food source, over a culture period of 20 days.

This short research note provides insights on the invasive apple snails (Pomacea spp.) and rice cultivation in Brunei Darussalam. This freshwater invasive snail was first detected in 2009, but it was never introduced intentionally. Since then their population has increased swiftly and spread to almost all the rice areas across the country, becoming a major pest of irrigated transplanted rice. Research and collaboration among infested countries is important for accurate species identification and better understanding of the invasion pathways.

The Sindh Province of Pakistan is very rich in aquatic resources and has a strong irrigation network. Farmers, after facing immense agricultural problems, now are considering aquaculture as an alternate option and converting their properties for aquaculture production. Commercial pond-based carp culture has significantly expanded and is now widely practiced in Sindh. Carp farmers have been making good profits and achieving high yields. Although aquaculture presently plays a modest role in the national economy of Pakistan its future prospects are bright.