title: Ragworm fatty acid profiles reveals habitat and trophic interactions with halophytes and with mercury.
abstract: The present study aimed to assess if ragworm fatty acids (FA) profiles could be used to discriminate their spatial distribution in an historically mercury-contaminated estuarine environment, i.e., if it was possible to differentiate ragworms present in salt marsh sediments surrounding plant roots and rhizomes (rhizosediment) from adjacent unvegetated sediment. Additionally, we also tried to determine if ragworms differed in mercury content and if these values could also be used to identify the habitat they occur in. Results show that, within the same area, ragworms can be distinguished using FA profiles and that in halophyte rhizosediment ragworms display more than twice the levels of alpha-linolenic acid (18:3n-3). The ratio cis-vaccenic/oleic acids (18:1n-7/18:ln-9) in ragworms suggests higher carnivory in unvegetated sediments. Our study indicates that ragworm FA profiles can be used to identify their habitat, their trophic interaction with halophytes and reveal a spatially contrasting feeding behaviour, which also reflects mercury accumulation.
authors.affiliation: Departmento de Biologia & CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal. lillebo@ua.pt
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Lillebø
authors.forename: Daniel Francis Richard
authors.initials: DF
authors.lastname: Cleary
authors.forename: Bruna
authors.initials: B
authors.lastname: Marques
authors.forename: Alberto
authors.initials: A
authors.lastname: Reis
authors.forename: Teresa
authors.initials: T
authors.lastname: Lopes da Silva
authors.forename: Ricardo
authors.initials: R
authors.lastname: Calado
mesh_terms: D000818:Animals; D004784:Environmental Monitoring / Q000379:methods*; D005227:Fatty Acids / Q000378:metabolism*; D020387:Food Chain; D019015:Geologic Sediments / Q000737:chemistry; D008628:Mercury / Q000032:analysis*; D011077:Polychaeta / Q000378:metabolism*; D055051:Salt-Tolerant Plants / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005227:Fatty Acids; D014874:Water Pollutants, Chemical; D008628:Mercury