UPTAKE OF ORGANIC MATERIAL BY AQUATIC INVERTEBRATES .6. ROLE OF EPIFLORA IN APPARENT UPTAKE OF GLYCINE BY MARINE CRUSTACEANS

Soft-bodied marine invertebrates from most invertebrate phyla are capable of taking up amino acids from seawater. Marine crustaceans were originally reported not to accumulate amino acids. Artemia salina, Limnoria tripunctata, Tigriopus californicus, and Corophium acherusicum were examined for their ability to accumulate C14-labelled glycine from dilute solution in seawater. In initial experiments with Artemia and Limnoria the organisms were found to become very radioactive. When animals were preincubated in streptomycin or in a mixture of antibiotics, uptake of the C14-glycine was drastically reduced. Microorganisms associated with the arthropods and in the culture media were found capable of accumulating C14-labelled glycine. Efforts to demonstrate removal of amino acids from seawater by colorimeteric determination of material remaining in the medium were unsuccessful. The microorganisms responsible for the uptake are apparently associated with the exoskeleton of the organisms and not the gut. There is probably no substantial contribution to the nutrition of these crustaceans by the epiflora. Preincubation in the antibiotic mixture depressed the uptake of C14-glucose and C14-acetate by about an order of magnitude. It is concluded that there is no evidence for accumulation or assimilation of small organic compounds by the small crustaceans examined. © 1969 Springer-Verlag.