Spatial changes in fatty acids signatures of the great scallop Pecten maximus across the Bay of Biscay continental shelf. (15th October 2015)

• Record Type: Journal Article
• Authors: Nerot, Caroline; Meziane, Tarik; Schaal, Gauthier; Grall, Jacques; Lorrain, Anne; Paulet, Yves-Marie; Kraffe, Edouard
• Is Part Of: Continental shelf research. Volume 109(2015)
• Page Start: 1
• Page End: 9
• Publication Date: 2015-10-15
• Subjects: Pecten maximus -- Fatty acids -- Trophic markers -- Depth gradient -- Metabolism; SFA saturated fatty acids -- MUFA monounsaturated fatty acids -- BFA branched fatty acids -- PUFA polyunsaturated fatty acids -- TFA total fatty acids -- DHA docosahexaenoic acid, 22:6n-3 -- EPA eicosapentaenoic acid, 20:5n-3; Continental shelf -- Periodicals; Submarine geology -- Periodicals; 551.41
• DOI: 10.1016/j.csr.2015.08.032
• Languages: English
• ISSNs: 0278-4343

Abstract

Abstract: The spatial variability of food resources along continental margins can strongly influence the physiology and ecology of benthic bivalves. We explored the variability of food sources of the great scallop Pecten maximus, by determining their fatty acid (FA) composition along an inshore–offshore gradient in the Bay of Biscay (from 15 to 190 m depth). The FA composition of the digestive gland showed strong differences between shallow and deep-water habitats. This trend was mainly driven by their content in diatom-characteristic fatty acids, which are abundant near the coast. Scallops collected from the middle of the continental shelf were characterized by higher contents of flagellate markers than scallops from shallow habitats. This could be related to a permanent vertical stratification in the water column, which reduced vertical mixing of waters, thereby enhancing organic matter recycling through the microbial loop. In the deeper water station (190 m), FA compositions were close to the compositions found in scallops from shallow areas, which suggest that scallops could have access to the same resources ( i.e. diatoms). Muscle FA composition was more indicative of the physiological state of scallops over this depth range, revealing contrasting reproductive strategies among the two coastal sites and metabolic or physiological adaptation at greater depth ( e.g. structural and functional adjustments of membrane composition). This study therefore revealed contrasted patterns between shallow and deeper habitats for both P. maximus muscle and digestive gland tissues. This emphasizes the variability in the diet of this species along its distribution range, and stresses the importance of analyzing different tissues for their FA composition in order to better understand their physiology and ecology. Abstract : Highlights: Spatial variability in fatty acids of P. maximus between 15 and 190 m depth. Strong discrepancy in FA of digestive glands between shallow and deep stations. Hydrological structures influence the prevalent food sources for scallops. Muscle FA composition was more indicative of the physiological state of scallops over this depth range. FA approach relevant to study scallops trophic ecology with spatial perspective.