Phospholipids are natural, integral parts of cells. They are sometimes referred to as the “molecule of life”, due to their role in maintaining the cell membranes’ strength, flexibility, and integrity. Inclusion of phospholipids in the diets of marine fish has proven, through scientific research, to have a positive effect on the culture performance of fish, particularly in terms of growth. This makes it an essential component in the diets of larval and juvenile fish, as it’s critical to ensure high survival rates at these life stages.
However, not all phospholipids are created equal. Marine phospholipids, such as those delivered via krill, are shown to possess a higher nutritional value, versus plant-based phospholipids. One of the advantages of krill is that the omega-3s are mainly bound to phospholipids, rather than trigylcerides, as in fish oil. With phospholipids as the mechanism of delivery, the fish experience much better absorption and positive health effects from the omega-3s, also present in krill.
Krill phospholipids stimulate fish larvae growth and development
For marine fish larvae, krill phospholipids are proven to enhance growth in terms of weight and length. There is also evidence that the phospholipids stimulate skeletal mineralization, which reduces the chance for malformation in the larvae stage.
With krill in the diet, the larvae digestive systems show improved functioning, along with greater utilization of lipids which reduces the occurrence of intestinal absorptive cell injuries and reduces the fat accumulation in liver. It’s also important at this stage to increase stress resistance and survival rates of the larvae, which krill phospholipids do through the improved transport of fatty acids and lipids.
Watch an interview between VP QRILL Sales, Kjetil Ribe and Dr. Tibiabin Benitez- Santana below:
Juvenile stage marine fish show improved feed intake with krill phospholipids
It’s not just the larvae that benefit from the addition of krill phospholipids in their diet. Feed intake is an important factor at the juvenile stage, in order to support the growth and nutrition levels of the fish. By adding krill phospholipids to the juvenile diets, the fish will exhibit enhanced lipid mobilization in their livers and overall improved dietary lipid utilization. It’s also apparent that the intestines of fish juveniles are better protected with the aid of krill phospholipids, which contributes to the overall health of the fish.
See film below to learn about krill for larval and juvenile stage.
Krill in diets leads to faster growth and improved health
Over the years, krill has increasingly caught the attention of marine researchers due to its powerful effects on fish health, making it a natural replacement for fish meal in aquaculture diets. Studies on various marine species reveal consistent findings on the effects of krill on growth performance and feed utilization. That means that krill boosts feed intake among its fish consumers, stimulating faster growth and earlier harvest weight attainment. Studies also show that a krill-supplemented diet leads to improved health, due to high-levels of omega-3, and greater disease resistance, from known pathogens for example. In a recent study on olive flounder in South Korea, krill meal was proven to have a positive effect on the survival rates of this marine fish species, resulting in increased resistance to the bacterial pathogen Edwardsiella tarda. This boosted immune response could be explained by the rich nutrient profile of krill.
A sustainable source of phospholipids for early larval and juvenile development
Sustainability of marine fish feed ingredients is increasingly under scrutiny, leading to a key aquaculture industry recommendation to include marine ingredients from lower trophic levels in fish feeds. Krill is low on the food chain, with a large and healthy biomass, and is closely monitored by a strictly governed krill fishery. Producers, such as Aker BioMarine, continually work to advance their harvesting technology and keep their catch well below the set limits, making krill a sustainable ingredient for a nutrition-packed and health-enhancing marine fish diet.