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Evolution of fatty acid profiles of subtidal and rocky shore mussel seed (Mytilus galloprovincialis, Lmk.). Influence of environmental parameters

Abstract:

In the present study fatty acid profiles of Mytilus galloprovincialis mussel seeds originating from two habitats with different environmental conditions (rocky shore and subtidal) were compared after transfer to the same environmental habitat (subtidal). The aim of the research was to investigate the influence of various environmental parameters on the relative percentage of fatty acids. The study was based in the Arosa Ría, Northwest Spain, between 27th November 1995 and 3rd July 1996. The location of the mussels suspended from the raft, the rope density (1.6 kg m-1) and cultivation depth (1.5-5.0 m) were common parameters for both mussel groups. Our results show that during the first 36 days of the experimental period the mussel origin participated significantly in the model explaining the variance of various fatty acids of physiological importance in marine bivalves, namely the acids 18:0, 16:1n-7, 18:1n-9, 18:1n-7, 18:2n-6, 18:3n-3, 18:4n-3, 20:2NMID1, 20:5n-3 and 22:6n-3. In addition, other environmental parameters related to food availability, such as the ratio chl-a/POM and TPM, only participated in the explanation of two and three of these acids, respectively. In contrast, 50 days into the experiment the mussel origin did not participate in the model of variance of the fatty acids studied, and the ratio ch1-a/POM participated significantly in the model explaining the variance of 11 of the total (16) selected fatty acids studied. Moreover, the coefficients were only positive in the fatty acids of known energetic importance in marine bivalves, namely the acids 14:0, 16:1n-7, 18:1n-7, 20:5n-3 and the ratio PUFAs n-3/n-6. The influence that mussel origin and various environmental parameters could exercise on the variability of diverse fatty acids of both mussel groups is discussed. © 2002 Elsevier Science B.V. All rights reserved.