STEROID-METABOLISM IN RELATION TO THE REPRODUCTIVE-CYCLE IN ASTERIAS-RUBENS L

1. Conversion rates of dehydroepiandrosterone, progesterone, and androstenedione were studied in gonad and pyloric caeca tissue of female and male sea star, Asterias rubens, at each stage of the reproductive cycle. 2. Each steroid has its own pattern of maximal and minimal conversion rates during the reproductive cycle. 3. The combined patterns of the conversion rates for the three steroids during the reproductive cycle suggest a strict sequence in each organ. These patterns seem to be sex- and organ-specific. 4. Steroid metabolism reaches maximum values at the onset of gonadal growth and at the end of the reproductive cycle. This suggests that steroids are important at least at these phases of the reproductive cycle.