. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. UPTAKE OF AMINO ACIDS BY OPHIACTIS 181 O < O Q < o: LJ _J m o CO o X O O 40 30 20 10. 8 10 TIME (DAYS) FIGURE 5. Radioactivity in the alcohol-insoluble fraction expressed as percentage of total radioactivity in Ophiacfis exposed to glycine-C" for 30 minutes at various periods of time following transfer to 60% sea water. In every case, ten animals each in 60% and 100% sea water were used. Open circles, 60% sea water; solid circles, 100% sea water. with mussel beds and with sponges involves a microhabitat concerning
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. UPTAKE OF AMINO ACIDS BY OPHIACTIS 181 O < O Q < o: LJ _J m o CO o X O O 40 30 20 10. 8 10 TIME (DAYS) FIGURE 5. Radioactivity in the alcohol-insoluble fraction expressed as percentage of total radioactivity in Ophiacfis exposed to glycine-C" for 30 minutes at various periods of time following transfer to 60% sea water. In every case, ten animals each in 60% and 100% sea water were used. Open circles, 60% sea water; solid circles, 100% sea water. with mussel beds and with sponges involves a microhabitat concerning which we have no chemical information whatever. Nonetheless, it is worth looking at the relation between the observed rate of amino acid accumulation and the metabolic needs of the animal. Measurements of the oxygen consumption of animals in the size range of 10 to 30 milligrams wet weight, using a Gilson respirometer, gave approximately ml. O2 This is roughly equivalent to 147 micrograms of glycine/ Our measurements indicate that the animals can obtain 64 micro- at an ambient concentration of 10 micromoles glycine per liter ( ). This is roughly the concentration of glycine measured in the interstitial water of mud flats (Stephens, 1963) and in inshore water samples (Belser, 1959, 1963). This represents 43% of the organic material necessary to support the observed oxygen consumption. Since we have no information concerning conditions in the immediate environment of these brittle stars, we can only note that very modest ambient concentrations would permit this pathway to make a significant contribution to the energy needs of the organism. The production of C14(X indicates that the amino acids entering the organism are available for oxidation. Assimilation of labelled carbon into the alcohol- insoluble fraction implies that this material contributes to synthesis path\vays. A rough estimate concerning the relative magnitude of the con
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
