Content of amino acids in adult tapeworm Ligula intestinalis (Pseudophyllidea)

17 amino acids (AA) were determined in adult specimens of the tapeworm Ligu la intestinalis, from the intestine of cormorant (Phalocrocorax: carbo). In comparing the AA values in adult tapeworms with those in plerocercoids fro m the body cavity of various fishes, in adult tapeworms statistically highl y significantly higher values were found in threonine, valine, tyrosine, ph enylalanine, lysine, aspartic and glutamic acids, proline and alanine. An e xtremely high increase of the values in lysine and phenylalanine suggests a n important role of these AAs in the protein synthesis at maturation, sexua l organ development and egg production in this tapeworm species.