The distribution of amino acids in 14 sponges was surveyed qualitatively by paper chromatography. Dried acetone-extracted sponge material was treated with 95% alcohol to remove soluble amino acids and peptides. From two sponges this material consisted largely of peptides, five of which were hydrolyzed and examined. From the present data it appears doubtful that any significant correlation exists between the amino acid distribution in sponges and the biological classification of these organisms.
Inskip, Lois W., and Harold G. Cassidy. 1955. "On the amino acids of sponges." Journal of Marine Research 14, (3). https://elischolar.library.yale.edu/journal_of_marine_research/835