Omega-3 on the fly: long-legged fly Machaerium maritimae as a potential source of eicosapentaenoic acid for aquafeeds

Abstract

The need for more sustainable aquafeeds has prompted the exploration of insects as potential ingredients. However, commonly reared insects are not satisfactory regarding their fatty acid composition, lacking omega-3 long chain polyunsaturated fatty acids (n-3 LC PUFA), important nutrients for marine organisms. In this study, we present in detail the fatty acid profile of the long-legged fly Machaerium maritimae Haliday (Diptera: Dolichopodidae), an amphibiotic insect native to European coastal habitats. Specimens of this fly were collected in Ria de Aveiro coastal lagoon (Portugal) and the fatty acid profile was analysed through gas chromatography coupled with mass spectrometry. Results revealed a remarkably high level of n-3 LC PUFA, (11 μg/mg dry weight, 20% of the fatty acid profile) namely eicosapentaenoic acid, and a low level of saturated fatty acids. This value is higher than what is found in Hermetia illucens (black soldier fly), while comparable to other aquatic insects. We also report the presence of 50 distinct fatty acids, including multiple branched-chain and PUFA, and discuss potential implications of their presence on the ecology of this species. Variation in the fatty acid profile along the landscape is also presented. Our results indicate that M. maritimae can potentially be a high-quality lipid source for marine aquafeeds. Current legislation in Europe allowing the use of insects in aquaculture is restricted to a few selected species, often non-native, however, further research should consider native insects as potential alternatives to current ingredients in aquafeed.

Fatty Acid Profile and Escherichia coli and Salmonella sp. Load of Wild-Caught Seaweed Fly Fucellia maritima (Haliday, 1838) (Diptera: Anthomyiidae)

“…This lower lipid content is closer to that displayed by other species of seaweed flies, such as Coelopa frigida (12.1% to 19.7%) and C. pilipes (14.2% to 16.8%) [ 7 ]. This value is also similar to other coastal fly species Machaerium maritimae, at 12.0% [ 6 ]. The lower levels of fats in F. maritima might be an indication of high protein content, as it occurs in other insects species [ 21 ].…”

“…Another potential option to help solve this ingredient crisis are insect-based meals, although terrestrial insects are relatively deficient in n-3 LC-PUFAs [ 3 ]. Curiously, coastal insect species are known to naturally have LC-PUFAs in their biochemical profiles [ 6 , 7 ], and their potential use as aquafeed ingredients remains to be fully investigated [ 8 ].…”

The Potential Impacts by the Invasion of Insects Reared to Feed Livestock and Pet Animals in Europe and Other Regions: A Critical Review

“…Recently, the long-legged fly Machaerium maritimae Haliday, 1832 (Diptera, Dolichopodidae) (Figure A5j), a fly species native to western Europe, adapted to thrive in brackish waters, was reported as a potential feed ingredient for aquaculture due to its content in important omega 3 PUFA, including eicosapentaenoic acid (EPA), an essential nutrient for the healthy growth of marine organisms [210].…”

El raro chinche de las marismas Teratocoris antennatus (Boheman, 1852) (Hemiptera, Miridae), nueva especie para Portugal

“…For this reason, rare species such as T. antennatus may be at risk in these threatened environments. Ria the Aveiro lacks important entomological research, so sampling often results in new records, for instance, Lourenço et al (2020) Insects play important ecological roles in the ecosystems due to their diversity, abundance, and wide range of feeding habitats, and even have potential biotechnological uses (Duarte et al 2021). Since they are vulnerable to habitat disturbances they can be used as indicators of ecological changes (Ameixa et al, 2018), which can contribute to monitor ongoing environmental changes.…”