News & Views Fish Nutrition Research
Superworm larva meal improves gilthead seabream immune system

Partial dietary fishmeal replacement with full-fat or defatted superworm (Zophobas morio or ZM) larva meals has been found to modulate the innate immune system of juvenile gilthead seabream, Sparus aurata. This was shown in a study conducted in Greece.

“The different effects of LF (low-fat)and full-fatted ZM on the antibacterial activity of the fish sera against E. coli suggested that lipid-bound compounds present in ZM meal may have either a direct antibacterial activity or stimulate the fish to increase their antibacterial activity,” said authors, Henry et al. Details of the study was published on Aquaculture Reports.

The research team said FF and LF ZM meals immodulated the animal at various dietary levels.
Neutrophil percentage was increased by dietary ZM. This result improved further when 20 percent of defatted ZM was used. Neutrophils are a type of white blood cell that help the immune system fight infections and heal injuries.
Compared to fishmeal-based diet, the control, antibacterial activity of fish serum was increased in fish fed the full-fat.

Nitric oxide serum was increased by dietary defatted ZM. No cases of inflammation were observed in ZM-fed animals.

“These findings suggest that dietary Z. morio can immunomodulate gilthead seabream but further infectious challenge studies will have to be performed to determine if these effects are translated into an increased resistance to diseases,” they said.

Results of the study aside, the much overlooked ZM ticks a number of boxes as a protein-source replacement. Supply is yet to be tapped for human diet. It is considered a pest in grain and flour, and it can be raised on low-nutritive plant substrate.

Gilthead seabream is a major fish species farmed in Europe.