The Fish Egg Standard
…we can make educated guesses about the needs of a larval fish by examining what nature provides… the nutritional profile of healthy eggs of each species…
It is clear that the nutritional profile of healthy eggs is the intended nutrition larval fish need before first feeding. However, it is a bit harder to argue optimal nutrition at first feeding and thereafter.
The nutritional needs of larval fish are a matter of much research and debate. There is considerable understanding of the metabolic pathways for uptake of nutrients, but there is still much that is not understood. Fortunately we can make educated guesses about the needs of a larval fish by examining what nature provides.
Many studies of individual species have analyzed the nutritional profile of the egg, gonad, newly hatched larva, and wild prey organisms. Fortunately, for most species there seems to be a convergence of the nutritional profiles of each of these sources. This allows the nutritional profile of healthy eggs of each species to be used as a simple proxy for the nutritional goals for feed rotifers for that species.
This approach has been used to assess the fatty acid and lipid class requirements of larval fish, and can probably be used to assess other nutritional needs such as vitamins, carotenoids, protein, carbohydrates and minerals. This is the approach we use at Reed Mariculture in formulating our feeds, and the approach advocated by this document.