Advances in marine fish larval nutrition: the challenge of feeding the smallest living vertebrates

Advances in marine fish larval nutrition: the challenge of feeding the smallest living vertebrates

The future of fish production is highly dependent on the production of high quality and healthy fry (larvae) and juveniles, so the question is how to maintain high production standards and lower its costs without choosing unsustainable practices? Providing the adequate nutrition and fulfilling all the nutritional requirements are one of the key-factors for a successful growth, development and survival of fish larvae and juvenile. In this context, mass production of fish larvae is one of the main bottlenecks of the aquaculture industry, and consequently, larval nutrition from a quantitative and qualitative points of views is of utmost importance. Generally, fish larvae are fed enriched rotifers (Brachionus spp.) at the onset of exogenous feeding, followed by a period of feeding with enriched brine shrimp (Artemia spp.) before the larvae are weaned onto formulated feed. Additionally, some authors have reported the use of copepods due to their advantages as live prey (swimming activity, nutritional value and size). Although these practices are well known and standardized for most of the commercially important fish species, there still exists important gaps in knowledge regarding the nutritional requirements of fish larvae at different stages of development. Complete reliance upon live food organisms for larviculture is undesirable, but over four decades of research into developing micro-diets for start-feeding marine fish larvae have not met with universal success. Although some success has been achieved, it is clear that the development of micro-diets for a wider range of species would provide tremendous benefits for larviculture: reducing the time, effort and space required for the production of the live food organisms, and ensuring that the fish larvae were being fed a diet of uniform nutritional composition. As such, research directed towards the production of effective micro-diets is one of the key areas within larviculture. Thus, this presentation seeks to present an overview of the state-of-the-art in fish larvae nutrition (requirements in macro- and micronutrients) considering available data of fish larvae fed live prey and microdiets, as well as the limitations of using live prey for nutritional studies.

The future of fish production is highly dependent on the production of high quality and healthy fry (larvae) and juveniles, so the question is how to maintain high production standards and lower its costs without choosing unsustainable practices? Providing the adequate nutrition and fulfilling all the nutritional requirements are one of the key-factors for a successful growth, development and survival of fish larvae and juvenile. In this context, mass production of fish larvae is one of the main bottlenecks of the aquaculture industry, and consequently, larval nutrition from a quantitative and qualitative points of views is of utmost importance. Generally, fish larvae are fed enriched rotifers (Brachionus spp.) at the onset of exogenous feeding, followed by a period of feeding with enriched brine shrimp (Artemia spp.) before the larvae are weaned onto formulated feed. Additionally, some authors have reported the use of copepods due to their advantages as live prey (swimming activity, nutritional value and size). Although these practices are well known and standardized for most of the commercially important fish species, there still exists important gaps in knowledge regarding the nutritional requirements of fish larvae at different stages of development. Complete reliance upon live food organisms for larviculture is undesirable, but over four decades of research into developing micro-diets for start-feeding marine fish larvae have not met with universal success. Although some success has been achieved, it is clear that the development of micro-diets for a wider range of species would provide tremendous benefits for larviculture: reducing the time, effort and space required for the production of the live food organisms, and ensuring that the fish larvae were being fed a diet of uniform nutritional composition. As such, research directed towards the production of effective micro-diets is one of the key areas within larviculture. Thus, this presentation seeks to present an overview of the state-of-the-art in fish larvae nutrition (requirements in macro- and micronutrients) considering available data of fish larvae fed live prey and microdiets, as well as the limitations of using live prey for nutritional studies.