Collectively carps represent the largest global aquaculture sector, contributing over 20 percent of global aquaculture production. The Indian major carps including catla (Catla catla), rohu (Labeo rohita) and mrigal (Cirhinnus mrigala) are cultured widely across the Indian sub-continent with the main culture system being a multi-species polyculture in ponds, often including other carp species. This production sector is supported by major seed supply systems producing over 50 billion seed per annum. This case study analyses genetic management of Indian major carps since they were first domesticated with the development of hypophysation techniques in the 1950s. A review of literature and a survey of common hatchery practices identifies significant problems prevalent in the sector brought about by a lack of application of best practices in genetic management resulting in loss of genetic diversity, inbreeding and uncontrolled hybrid introgression.

In this issue:

• Pathway to aquaculture biosecurity: Mitigating risks, managing progressively and engaging the value chain
• Important considerations for feed and feeding management during Indian catfish culture
• A transitional journey from fisheries to aquaculture in Moyna
• Colour widow tetra: A new and highly preferred aquarium fish in West Bengal
• Expanding the horizon of aquaculture through women's empowerment
• NACA Newsletter

Known as ‘glow widow tetra’, ‘glow skirt tetra’, ‘colour widow tetra’ in the ornamental fish industry, a genetically modified variety of the black widow tetra Gymnocorymbus ternetzi is the most favoured by aquarium fish hobbyists in West Bengal. Stunning and sparkling red, blue, yellow, green, pink, orange, and purple bodied colour variations of this tetra have been developed through gene transfer or transgenic technology. The fish glow when kept under blue LED lights, hence the name ‘glowfish’. Maintenance of these brightly coloured and reasonably priced fish in small and medium-sized aquariums at home, the office, hotels, and other settings has become popular in West Bengal, India.

This story looks back over the last century at the fisheries scenario in Moyna, a community development block in West Bengal, India. The tremendous success of aquaculture practice in Moyna has strongly influenced farmers of surrounding districts to convert agricultural lands to aquaculture. Capture fisheries in Moyna have had a rich heritage that has gradually evolved over time. Beginning with traditional deep-water paddy-cum-capture fishery, as practices evolved the fish component of the crop began to take on greater significance, becoming the most profitable part. Over time, farmers have shifted to an aquaculture model, achieving an average yield of 12.5 tonnes/ha/year. 

Natural feeds present in ponds contribute to some extent to the nutrition of fish cultured therein. But these natural food stocks become insufficient as production intensity rises. In semi-intensive and intensive systems, nutritional inputs must be partly or wholly supplemented using external feeds to support higher growth and productivity. Good quality feed is essential to achieve higher production. The selection of proper feedstuff and good formulation to meet the requirements of the cultured species will enhance acceptance and utilisation. This article discusses feed preparation, ration size, feeding rate, feed distribution and feeding schedules for culture of Indian catfishes.