The composition of tunic from four species of ascidians

Abstract

1. 1. Dry tunic from four species of ascidians contains between 37–67% protein and 33–63% carbohydrate. 2. 2. Tunicin from Corella willmeriana and Ascidia paratropa yields approximately 100 per cent of its dry weight as cellulose equivalents when determined by the phenol-sulfuric acid method, but Pyura haustor and Cnemidocarpa finmarkiensis tunicin yields only about 50 per cent of its dry weight as cellulose equivalents. 3. 3. Amino acids analyses of tunic from the four species reveal a striking similarity in relative amino acid composition with all four species displaying a high acidic amino acid tunic content. 4. 4. Tunic amino acid analyses demonstrate the presence of hexosamine in the tunics of all four species. 5. 5. No hydroxyproline is recovered in the amino acid analyses of tunic from these species.