Larval rearing is one of the essential steps for closing life cycle loops in aquaculture and thus there will be a big market for larval feeds with high nutritional value. The cost of feeds accounts for 50% to 70% of the total production costs in an aquaculture farm. It is therefore essential to choose and use the most cost-effective feeds that could support good fish larvae growth performance. Presently, rearing of the majority of marine fish larvae requires the use of live feeds such as rotifers and Artemia nauplii. However, shortage of live feeds can occur due to seasonal availabilities and culture issues. As such, the live feed supply may not be able to meet the demand of a fast-growing aquaculture industry, which requires a continuous and reliable supply throughout the year for hatchery production. As such, this featured technology is developing an encapsulation technique for targeted delivery of essential nutrients such as proteins and lipids into digestion systems of marine fish larvae.
The encapsulation technology is based on layer-by-layer (LbL) assembly technique to obtain larval microcapsules enwrapping essential nutrients such as lipids and amino acids. The dual stimuli-responsive properties of edible biopolymer-based materials are adopted as outer layer shells or coats to protect the essential nutrient, whose release can be triggered by a change of pH and ionic strength in the larval fish gut. The microcapsules are showing five main features and characteristics, as follows: (1) small and uniform particle sizes that are also readily detectable and consumable by fish larvae (~50-100 μm); (2) easily digested in the digestive tract of fish larvae; (3) high stability and stronger coating materials so that the encapsulated nutrients do not leach out while in the water; (4) optimal floating and suspension time so that the first-feeding larvae can easily capture them, and (5) the coating materials of the microcapsules can swell and degrade in the larval gut to release the dietary ingredients for digestion and assimilation.
This technology develops an encapsulation technique which targets delivery of essential nutrients such as proteins and lipids into digestion systems of marine fish larvae. As an alternate feed for aquaculture industry, this can be apply to the following: Marine or freshwater larviculture industry Formulation of larviculture feeds Partial or full replacement for live larval feeds
Bring down operation cost of larviculture industry Ensure continuity of supply and price stability of larviculture feeds The composition of nutrients can be tailor-formulated for the growth of fish larvae Good digestibility in the larval fish gut Customised particles sizes that are readily detectable and consumable by fish larvae Increase the survival rate of fish larvae Improvement of feed conversion