A LIPIDOMIC APPROACH TO IDENTIFYING IMMUNE RESPONSE IN ATLANTIC BOTTLENOSE DOLPHIN (<i>TURSIOPS TRUNCATUS</i>) IN RESPONSE TO THE ATTACHMENT OF EPIBIOTIC TASSEL BARNACLE (<i>XENOBALANUS GLOBICIPTIS</i>)
Hall, Alina Mar
Wild delphinids are a group of active, social, and long-lived aquatic mammals. Marine species of dolphins have smooth, waterproof epidermis with various self-cleaning mechanisms including increased rates of cornification and desquamation when compared to rough-skinned whales. This largely prevents attachment of epibionts on dolphins apart from the cosmopolitan tassel barnacle, <i>Xenobalanus globicipitis</i>. In a poorly understood behavior, barnacle cyprids locate their dolphin host, secrete a temporary adhesive to begin attachment, and metamorphose into the juvenile form. Once metamorphosed, the barnacle begins to form calcareous plates at its base projecting basally into the epidermis. This induces a localized redness, indictive of inflammation, which is eventually resolved as the barnacle continues to grow. This study investigated this immune response utilizing a lipidomic approach to compare lipid profiles in dolphins with and without this barnacle attached to the skin. Results found a significant up-regulation of lipids potentially associated with inflammation mediation in non-host dolphins, suggesting an association between reduced immune function in dolphins and increased attachment of <i>X. globicipitis</i>. Five upregulated diacylglycerol ethers (DAGE), two triacylglycerols (TG), and two phosphatidylcholine (PC) lipids all suggest a higher level of immune activity in non-host dolphins. Additionally, differences in lipid profile by sex congruent with dimorphic differences observed in human and rodent lipid profiles were observed.