Mass Culture and Enrichment of Brachionus calyciflorus: Strategies to Improve Freshwater Fish Larval Survival

Abstract

The early larval stage remains a critical phase in freshwater aquaculture because survival and growth depend strongly on the timely availability of suitable starter feed. This review examines the role of the freshwater rotifer Brachionus calyciflorus as a live feed organism for fish larvae, with emphasis on its culture, nutritional value, enrichment potential and application in larviculture. B. calyciflorus is suitable for early feeding because of its small body size, slow swimming movement, rapid reproduction and capacity to remain available in the water column for larval ingestion. Its culture can be initiated through isolation from freshwater sources, followed by pure culture, stock culture and upscaling in tanks using suitable feeds such as Chlorella vulgaris. Different production systems, including batch, semi-continuous and high-density culture methods, provide options for hatchery-scale use, although each method has limitations related to stability, water quality, labour and cost. The nutritional quality of rotifers can be improved through enrichment with essential nutrients such as vitamins, selenium and highly unsaturated fatty acids. Such enrichment is important because live feeds may naturally lack some nutrients required for optimal larval development. The manuscript also highlights the importance of enriched rotifers in supporting growth, survival, stress tolerance and biochemical composition in fish larvae. Despite these advantages, sustainable use of B. calyciflorus requires careful management of culture conditions, feeding, contamination control and enrichment protocols. Overall, B. calyciflorus represents a useful live feed option for freshwater fish larviculture and may contribute to improved hatchery performance when culture and enrichment practices are properly optimised.