COMPOSITION, ENERGY CONTENT AND FUNCTION OF STOMACH OILS OF PETRELS (ORDER, PROCELLARIIFORMES)

The stomach oils of Diomedae epomorphora Lesson, D. melanophris Temminck, D. chrysostoma Forster, D. bulleri Rothschild. Phoebetria palpebrata (Forster), Macronectes halli Mathews, Fulmarus glacialis (L.), Daption capense (L.), Pagodroma nivea (Forster), Pterodroma inexpectata (Forster), P. mollis (Gould), P. lessoni (Garnot), Procellaria aequinoctialis L., Puffinus tenuirostris (Temminck), P. griseus (Gmelin) and Hydrobates pelagicus (L.) were analyzed for lipid classes and energy contents. All oils contained 39-41 kJ/g. Triglycerides composed > 25% of the oils in 11 spp., while 10 spp. contained comparable amounts of wax esters. Squalene comprised 28% of the oil from Diomedae epomophora. Major lipid classes were not associated with any particular genera. A wide variety of fatty acid, fatty alcohol and glyceryl ether compositions were identified as the main components of each oil. That from Daption capense contained a unique composition of wax ester in which no C14 or C16 alcohols were present but significant proportions of myristic and palmitic acids were detected. The origin and function of the oils are discussed in terms of diet, preserving properties, water and energy stores and defenses.