Potential Use of Fatty Acid Profile for Artemia spp. Discrimination

The brine shrimp Artemia is of considerable economic importance in fish and shellfish larviculture. The quality of the Artemia product, differs, in terms of hatching and biometric characteristics, from strain to strain and from location to location. The same applies for their nutritional value which is not constant but varies among strains and within batches of each strain, causing unreliable outputs in marine larviculture. In the present paper we report and compare the fatty acid profiles of decapsulated Artemia cysts of thirteen Artemia populations from different species and geographical origins. Results showed that palmitic acid (16:0) was found in relatively constant proportions from 11.4 to 20.6% of total fatty acids in the cysts of all populations, while proportions of palmitoleic acid (16:1n-7) were higher in marine-type populations (18.6 to 19.1%) than in freshwater-type population (4.3 to 8.3%). In contrast, linoleic acid (18:2n-6) was observed in higher quantity in freshwater-type populations (4.0 to 8.1%) than in marine-type populations (3.1 to 3.3%). Furthermore, a higher n-3/n-6 HUFA ratio was observed in the marine-type population (>1) than in the freshwater-type population (<1). Principal component analysis revealed that total (n-3/n-6) HUFA ratio, C16:1(n-7), C20:5(n-3), C16:0/16:1 ratio and total (n-3/n-6) ratio are the most important variables for the differentiation between studied populations with a contribution of 49.6%. The analysis also showed that C16:1n-7, C18:2n-6, total n-3, total n-6 and total n-3 HUFA quantity as well as n-3/n-6 and n-3/n-6 HUFA ratio can also be used to discriminate between the different Artemia types. On the other hand, despite the intra-population differences observed (when comparing our results with literature data) in fatty acid structure, it is clear that the structure and the proportion of the different fatty acids as well as the assignment of a population to the marine-or freshwater-type is stable, suggesting that the fatty acid profile is both under a genetic control and being affected by the prevailing abiotic conditions.