Biochemical variations in Gigantocotyle explanatum and Gastrothylax crumenifer with respect to their seasonal reproduction.

Biochemical components, glycogen, protein, nucleic acids and lipid fractions were analysed every month from January to December 1986, in the liver and rumen amphistomes Gigantocotyle explanatum and Gastrothylax crumenifer, respectively. The results reveal a considerable seasonal variation. In the rumen amphistome the components reach their maximum level only once a year, whereas in the liver amphistome, more than one peak is observed in a year. In G. crumenifer the content of glycogen and nucleic acids increases before the onset of egg production while protein and lipids reach their maximum level during the egg production phase. The variations in biochemical components were associated with the reproductive cycles and gonad recrudescence of these parasites.