title: Temperature-induced changes in fatty acid dynamics of the intertidal grazer Platychelipus littoralis (Crustacea, Copepoda, Harpacticoida): Insights from a short-term feeding experiment.
abstract: Dietary lipids, and in particular the essential fatty acids (EFA), EPA (20:5ω3) and DHA (22:6ω3), guarantee the well-being of animals and are recognized for their potential bottom-up control on animal populations. They are introduced in marine ecosystems through primary producers and when grazed upon, they are consumed, incorporated or modified by first-level consumers. As the availability of EFA in the ecosystem is affected by ambient temperature, the predicted rise in ocean temperature might alter the availability of these EFA at the basis of marine food webs. Despite the FA bioconversion capacity of certain benthic copepod species, their lipid (FA) response to varying temperatures is understudied. Therefore, the temperate, intertidal copepod Platychelipus littoralis was offered a mono and mixed diatom diet at 4, 15 °C (normal range) and at 24 °C (elevated temperature) to investigate the combined effects of temperature and resource availability on its FA content and composition. P. littoralis showed a flexible thermal acclimation response. Cold exposure increased the degree of FA unsaturation and the EPA%, and induced a shift towards shorter chain FA in the copepod's membranes. Furthermore, a mixed diet reduced the impact of heat stress on the copepod's membrane FA composition. Temperature affected the trophic transfer of EPA and DHA differently. While dietary resources could fully compensate for the temperature effects on total lipid and EPA content in the copepods, no such counterweigh was observed for the DHA dynamics. Heat stress lowered the DHA concentration in copepods regardless of the resources available and this implies negative effects for higher trophic levels.
authors.affiliation: Marine Biology, Biology Department, Ghent University, Campus Sterre, Krijgslaan 281 - S8, 9000 Gent, Belgium. Electronic address: eva.werbrouck@ugent.be.
authors.forename: Eva
authors.initials: E
authors.lastname: Werbrouck
authors.affiliation: Marine Biology, Biology Department, Ghent University, Campus Sterre, Krijgslaan 281 - S8, 9000 Gent, Belgium. Electronic address: dirk.vangansbeke@ugent.be.
authors.forename: Dirk
authors.initials: D
authors.lastname: Van Gansbeke
authors.affiliation: Marine Biology, Biology Department, Ghent University, Campus Sterre, Krijgslaan 281 - S8, 9000 Gent, Belgium. Electronic address: ann.vanreusel@ugent.be.
authors.forename: Ann
authors.initials: A
authors.lastname: Vanreusel
authors.affiliation: Marine Biology, Biology Department, Ghent University, Campus Sterre, Krijgslaan 281 - S8, 9000 Gent, Belgium. Electronic address: christophe.mensens@ugent.be.
authors.forename: Christoph
authors.initials: C
authors.lastname: Mensens
authors.affiliation: Marine Biology, Biology Department, Ghent University, Campus Sterre, Krijgslaan 281 - S8, 9000 Gent, Belgium. Electronic address: marleen.detroch@ugent.be.
authors.forename: Marleen
authors.initials: M
authors.lastname: De Troch
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D058639:Cold-Shock Response; D033342:Copepoda / Q000378:metabolism* / Q000502:physiology; D004032:Diet; D005227:Fatty Acids / Q000378:metabolism*; D020387:Food Chain; D018869:Heat-Shock Response
chemical_list: D005227:Fatty Acids
keywords: Benthos; Biochemical ecology; Diatom; Marine; Storage lipids; Thermal acclimation