FREE AMINO ACIDS OF MARINE INVERTEBRATES 1, 
Primarily as a guide for more detailed investigations, we have conducted a pre- 
liminary survey of the free amino acids of the major marine phyla. All of the specimens 
were collected on the coast of San Diego county (Calif., U.S.A.), during the months 
of July and August. In the following discussion the designation “free amino acids” 
will be applied to those ninhydrin-reactive materials which are extractable by 80°% 
ethanol and which can be detected on two-dimensional paper chromatograms. An 
overall examination of the results confirms and expands the range of previous obser- 
vations!—}, 
High taurine concentrations were observed in many species. Mytilus edulis, the 
7 


—- —— mci is Pei ereth oe = — 
| 2 a 4 

» F oe. J » “. 
14 * 
Figs. 2-4. Fig. 2, a Siliceous sponge, Stelletta sp; Fig. 3, Calcareous sponges, Rhabdodermella 
nuttingt; Fig. 4, Xestospongia vanilla. Taurine, 5; glycine, 14. 
mussel, has been cited as the classic example of a marine organism with a high taurine 
concentration!’ 16. The high taurine concentration in the abalone, Haliotis, was 
observed at an equally early date’. Both of these species, and the octopus which 
also has been proposed as a commercial source of taurine!®: 19, exhibited the expected 
high levels of this amino acid. However, the relative content of taurine is even higher 
in some other species, e.g., Renilla kollikeri, the sea pansy. As observed by previous 
investigators® 8. 12, in many species the high taurine concentration was paired with 
an equally high glycine content. In some instances glycine alone was dominant7~??, 
and occasionally alanine was a major component. The expected high arginine concen- 
trations®: !* were evident throughout the Crustacea. This probably reflects the break- 
down of the phosphogen arginine phosphate. 
Little phylogenetic correlation is to be expected in such an extensive survey. Here 
we may profitably reflect on the observations of botanical biochemists who have found 
that phylogenetic correlations usually become more evident in intensive investiga- 
tions rather than extensive surveys. Another frequent observation is that the parallel 
References p. 186 
