Comparative study on the fatty acid composition of two marine vertebrates:striped dolphins and loggerhead turtles

The fatty acid composition of total lipids extracted from seven different t issues (fat, liver, cerebrum, cerebellum, lung, kidney and muscle) of 10 st riped dolphins (Stenella coeruleoalba) (weight 75.7 +/- 16.2 kg) found dead or moribund during a morbillivirus epizootic, and from two tissues (fat an d liver) of 54 loggerhead turtles (Caretta caretta) (18.5 +/- 10.5 kg) seiz ed dead after illegal capture, both from the Mediterranean Sea, have been d etermined by high resolution chromatography techniques. When comparing both species, fatty acid composition is surprisingly similar, with a predominan ce of the monoenoic followed by the saturated group of fatty acids, and a v ery close ratio of polyunsaturates n-3/n-6. The relatively high arachidonic acid content in the liver of the two marine species is remarkable. The sim ilar diet can play an important role in these findings, but it is suggested that probably metabolic pathways and essential fatty acid requirements bet ween both marine vertebrates are similar, more than is expected from their earlier filogenetic evolutionary divergence. (C) 1999 Elsevier Science Inc. All rights reserved.