ABSTRACT
Specimens of Ophioderma were fed small clams labeled with C amino acids, and after 8 to 24 hours sacrificed, sectioned, and studied as stripping film autoradiographs to observe translocation of the nutrient material. While some radioactivity was detected in the stomach tissues of the brittlestars, more notable concentrations were found in the hemal structures, especially the radial hemal canals. By 12 hours, this activity extended even to the arm tips. Label, at generally lower levels, was also seen in the oral hemal ring, axial organ (especially the aboral end), genital hemal connectives, transverse hemal canals, and in the connective tissue layer of the tube feet. Individual cells within the oral papillae also became highly labeled. Very little activity was found in the gonads, muscles, or most other parts not mentioned above. Additional experiments were conducted in which the brittlestars themselves were placed directly in the C nutrient medium before being processed into autoradiographs. These animals presented a similar picture of labeled nutrient distribution within the hemal tissues. Further, their epidermis, genital bursae, and mouth areas became heavily labeled. A sharp demarcation was noted between the oral epidermis and the much less labeled stomach tissue.
