UPTAKE OF FREE AMINO-ACIDS BY THE OPHIUROID MICROPHIOPHOLIS-GRACILLIMA (STIMPSON) (ECHINODERMATA) DURING DISC REGENERATION

1. Intact and regenerating brittlestars (Microphiopholis gracillima) t ake up several amino acids from artificial seawater, and show signific ant increases in uptake with food deprivation. 2. There were no differ ences in total amino acid uptake rates (determined by high performance liquid chromatography) between intact and regenerating animals. 3. No increases in the gross rate of leucine uptake were apparent in either group over time; however, glycine uptake increased significantly. 4. Catabolism of leucine and glycine, as evidenced by labeled CO2 release , was highest among intact animals that had been held for several days . 5. Dissolved leucine appears to be rapidly catabolized, while glycin e tends to remain in tissues.