Marine fungi cuisine for cultured fish

Fish oil is a major component in production of feed for cultured fish because of its high polyunsaturated fatty acid content. However, due to over-exploitation of fisheries, and being exasperated by environmental pressures there have been large reductions in fish oil stocks. Bara et al. (2017) examines alternatives to fish oil using microencapsulated and bioencapsulated Basidiomycota Rhodotorula spp. RNA/DNA ratio was quantified using the Quantifluor ONE dsDNA System and the Quantifluor RNA System, to determine if effectively delivered nutrients by Rhodotorula strains improve the nutritional condition of the target species. With both microencapsulated and bioencapsulated, RNA/DNA ratio was significantly higher in larvae fed with Rhodotorula spp. compared to the control showing Rhodotorula is an effective alternative to fish oil.

This paper provides a more sustainable alternative to commercial feed, highlighting the suitability of marine fungi as a food source for fisheries. In future studies other marine fungi could be examined to test their suitability, and to reinforce results in future papers gene expression related to growth could be investigated to track growth rates under the different diets. Criticisms I would give this paper is they don’t clarify the cost of producing the Rhodotorula spp compared to fish oil, or look at the long-term effects on fish of Rhodotorula as some species of Rhodotorula are known to cause disease.

Barra, M., Llanos-Rivera, A., Cruzat, F., Pino-Maureira, N., & González-Saldía, R. (2017). The Marine Fungi Rhodotorula sp. (Strain CNYC4007) as a Potential Feed Source for Fish Larvae Nutrition. Marine Drugs, 15: 369.