News & Views Fish Health Fish Nutrition
Improving the diet of European sea bass with Antarctic krill

A group of scientists from the Research Group in Aquaculture (GIA) IU-ECOAQUA (Spain) and Aker BioMarine, have discovered that the replacement of fishmeal with Antarctic krill meal in the diets of European sea bass, has shown positive results in growth performance, feed utilization, and liver metabolism.

In their study, scientists fed European sea bass a practical diet, with either a 15 percent fishmeal content, or the same diet substituted by 30 or 50 percent Antarctic krill meal for 12 weeks in triplicates.

Once feeding trials concluded, scientists carefully reviewed the fish’s growth performance, liver morphology, liver proximate composition, lipid classes and fatty acid profiles, as well as the expression of hepatic genes related with lipid metabolism were evaluated. Results were positive, showing a number of benefits for marine fish, if fishmeal was replaced with Antarctic krill meal.

Some benefits include:

• Dietary inclusion of krill meal in low fish meal diets has a positive effect on performance and health of European sea bass juveniles
• Improved fish growth by 20 percent, feed intake and specific growth rate feeding krill derived phospholipids rich in n-3 HUFA (appetite increased)
• Dietary krill meal decreases liver vacuolization levels and lower sings of steatosis
• Dietary krill meal modulates liver lipid metabolism and may decrease the synthesis of cholesterol levels in European sea bass liver

“A sustainable growth of the aquaculture industry implies the use of eco-friendly ingredients as alternative to the traditional marine protein and lipid sources,” says Silvia Torrecillas, senior researcher at GIA, PhD Fish Nutrition and Health. “Our results indicate that krill meal inclusion up to 7.5 percent as fishmeal replacer in practical diets for European sea bass improves growth performance, feed utilization and liver health status.”