FREE AMINO ACIDS OF MARINE INVERTEBRATES 181 

21 
com 
-— e. 
Figs. 17-21. Fig. 17, a sabellid worm, Sabellaria sp; Fig. 18, a peanut worm, Dendrostoma zosteri- 
colum; Figs. 19-21, a gooseneck barnacle, Mztella polymerus. Aspartic acid, 18; ethanolamine 
phosphate or the phosphodiester of ethanolamine and serine, 19; tyrosine-O-sulfate, 27; unknown 
amino acids, U, V, and W. 
poda which occupy “semiterrestrial” niches, their amino acid patterns more closely 
resembling those of terrestrial Arthropoda. 
Examples of chromatograms of extracts from representative marine Crustacea are 
those of a shrimp, Spzvontocarts picta (Fig. 26), a crab, Pachygrapsus crassipes (Fig. 27), 
and the spiny lobster, Panulirus interruptus (nerve) (Fig. 28). All show high levels of 
taurine, glycine and arginine, the shrimp also exhibiting tyrosine-O-sulfate and the 
crab and lobster high lysine concentrations. In addition, the chromatogram from the 
lobster nerve shows aspartic acid to be a major free amino acid in this tissue. The 
crab selected, P. crassifes, occupies ansecological niche intermediate between the 
“semiterrestrial” L. occidentalis and O. californiana and the subtidal S. picta and P. 
interruptus. It prefers to remain above the water level around tide pools. The free 
amino acid pattern is suggestive of this intermediate position, 
References p. 186 
