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Replacing dietary fish oil with Echium oil enriched barramundi with C18 PUFA rather than long-chain PUFA

journal contribution
posted on 2023-05-17, 04:25 authored by Ramez AlhazzaaRamez Alhazzaa, Andrew Bridle, Nichols, PD, Christopher CarterChristopher Carter
Vegetable oils (VO) are sustainable sources for replacement of fish oil (FO) in aquafeeds. However, VO lacks the health-benefitting n-3 long-chain (¡Ý C20) polyunsaturated fatty acids (n-3 LC-PUFA) and potentially compromise farmed fish flesh quality for consumers. In a factorial experiment, barramundi (Lates calcarifer) were grown in either freshwater or seawater and fed on three diets containing different oil sources: FO; stearidonic acid (SDA, 18:4n-3) rich oil from Echium plantagineum (EO); or rapeseed oil (RO). RO and FO-fed fish grew faster than the EO treatment and all three dietary treatments were not affected by salinity. A fatty acid mass balance showed that feeding barramundi on EO diet bypassed the first rate-limiting step in n-3 LC-PUFA biosynthesis. However, the fish did not accumulate high EPA or DHA content. Total PUFA, mainly of the n-3 series and dominated by ALA (18:3n-3) and SDA, in the whole body of EO fish was higher than for the FO and RO treatments. The n-3:n-6 ratio in EO treatment was less than for FO, but exceeded that in RO-fed fish. FA apparent metabolism as derived from the fatty acid mass balance fluxes showed comparable kinetics for key enzymes, indicating limited efficiency for LC-PUFA biosynthesis from their C18 dietary precursors in barramundi fed EO or RO containing diets. Fish digested dietary FA and accumulated them efficiently regardless of the salinity. These findings establish a more comprehensive understanding for FA metabolism in barramundi fed different dietary lipids and at extremes of the species wide salinity range. Based on the observed levels of accumulation, EO-fed barramundi are a potentially rich source of ALA and SDA for human consumption. Keywords: Lates calcarifer; Oil replacement; Fatty acid metabolism; Stearidonic acid


Publication title

Aquaculture: An International Journal Devoted to Fundamental Aquatic Food Resources










Institute for Marine and Antarctic Studies


Elsevier Science Bv

Place of publication

Po Box 211, Amsterdam, Netherlands, 1000 Ae

Rights statement

The definitive version is available at

Repository Status

  • Restricted

Socio-economic Objectives

Aquaculture fin fish (excl. tuna)

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