The sustainable growth of aquaculture relies on the diversification of ingredients for formulating aquafeeds. It is urgent to reduce pressure on conventional marine resources commonly employed to supply long-chain omega-3 polyunsaturated fatty acids (n-3 LC-PUFA), namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These two essential fatty acids are critical for the nutrition of farmed marine finish and shrimp species, yet their availability still heavily relies on fish stocks on the brink of overexploitation. In this context, marine gammarid amphipods, such as Gammarus locusta, emerge as a promising option, as they can perform the trophic upgrade of vegetable co-products into high-value biomass naturally rich in n-3 LC-PUFA.
In the present study, three consecutive generations (F1–F3) of G. locusta were cultured under the following diets: beetroot, bell pepper, carrot, green beans, peas, pumpkin, and fish feed (used as a control). Each generation began with 30 neonates (7 replicates per diet), reared to sexual maturity, and monitored for growth, reproductive output, and time to maturation. Fatty acid profiles of adults and offspring were analyzed using gas chromatography–mass spectrometry (GC–MS).
Our results showed that carrots led to slower growth and delayed offspring production in F1 compared to other diets. From F2 to F3, distinct patterns emerged across treatments, including distinct fatty acid profiles, variable offspring numbers, differential adult growth, and shifts in the timing of sexual maturity. These findings highlight that at least some vegetable co-products can sustain multigenerational cultures of G. locusta, although with species- and diet-specific trade-offs in performance.
This work contributes towards the development of a circular economy framework by merging green and blue food ecosystems.
This study was performed under project “BLUE BIOECONOMY PACT” (Project Nº. C644915664-00000026), co-funded by the Next Generation EU European Fund, under the incentive line “Agendas for Business Innovation” within Component 5—Capitalization and Business Innovation of the Portuguese Recovery and Resilience Plan (RRP), as well as project “PUFAPODS Merging blue and green food systems - Using marine gammarid amphipods supplied with plant food processing side streams to produce n-3 LC-PUFA” which is supported by FCT/MEC https://doi.org/10.54499/LA/P/0094/2020).