CHEMOTAXONOMY OF GYROCOTYLE (PLATYHELMINTHES, CERCOMERIA) SPECIES, PARASITES OF CHIMAERID FISH (HOLOCEPHALI), BY CHEMOMETRY OF THEIR FATTY-ACIDS

The validity of some morphological gyrocotylid species, exclusive gut parasites of ratfishes (Holocephali), is contested. Non-morphological characters, such as fatty acid profiles, may be used to resolve taxonomic problems. Five Gyrocotyle species were studied: three in Chimaera monstrosa collected between 1985 and 1987 from the north-east Atlantic (on the Norwegian coast); and two in Hydrolagus colliei, collected in 1987 from the north-east Pacific (in Nanaimo, British Columbia, Canada). Their fatty acids were obtained by methanolytic extraction of worm tissue samples, followed by gas chromatography of the fatty acid methyl esters, and finally multivariate data treatment (principal component analysis) of gas chromatographic results. Complete separation of the five species was obtained; classification agrees well with that arrived at by morpholog and enzyme electrophoresis. © 1990 Springer-Verlag.