In this issue:

• Neolissochilus hexagonolepis (chocolate mahseer): A flagship species for diversification of hill aquaculture in Northeast India.
• Aquarium fish culture in open village ponds in South 24 Parganas, West Bengal.
• Women nurtured transformative aquaculture in rural Bengal.
• Breeding and seed production technology of striped spiny eel Macrognathus pancalus to benefit fish farmers.
• Grow-out culture of the loach Lepidocephalichthys thermalis in modified tanks.
• NACA Newsletter.

This article investigates the ecological, economic, and cultural importance of Neolissochilus hexagonolepis, commonly known as chocolate mahseer and its potential for hill aquaculture in Northeast India. The taxonomy, distribution, and distinct features are described. Chocolate mahseer populations are in decline due to habitat degradation, overfishing and environmental changes, and it is designated as "near threatened" by the IUCN. Breeding patterns, growth parameters, and culture techniques are explored in depth as a candidate species for aquaculture development. Conservation initiatives and the need to balance economic utilisation with species conservation in chocolate mahseer farming are discussed.

The article highlights the successful commercial-scale breeding, propagation, rearing, and sale of aquarium fish species in the Howrah and South 24 Parganas districts of West Bengal, India. It focuses on the innovative practices of two experienced aquarium fish farmers, Sri Bikash Sau and Sri Swapan Parua, who have introduced a novel approach to aquarium fish culture in open earthen and common village ponds. The success stories of Sri Bikash Sau and Sri Swapan Parua serve as inspirations for small and medium-scale farmers and aqua-entrepreneurs. Their innovative approach to open pond production for aquarium fishes demonstrates the increasing potential and expansion of the aquarium fish business in the region.

Naihati fish seed market of West Bengal was established in 1976 and is the largest seed market in India. With the advent of induced breeding technology and hatcheries, fish seed is now available almost year-round, catering to the need of Indian farmers. Situated in North 24 Parganas, Naihati wholesale fish seed market is a well-known establishment that provides multifaceted services to stakeholders including fish seed growers, retailers, sellers, and mediators. This article describes the state of the market as aspects of its evolution over time.

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.