BODY-SIZE AND PERFORMANCE OF PATHWAYS OF CARBOHYDRATE-METABOLISM IN THE SEA-ANEMONE METRIDIUM-SENILE L

Flux through glycolysis and the pentose shunt pathway and the rate of glucose oxidation to CO2 were examined as functions of body mass in th e sea anemone Metridium senile. Minced tissues from anemones acclimate d to 5 degrees C and 15 degrees C were incubated in media containing i sotopically labeled glucose compounds to deter mine pathway fluxes. Do uble-logarithmic regressions showed that the specific rate of glucose oxidation declined significantly with increasing anemone mass at 15 de grees C (the mass exponent in the expression Y = aM(b) is b, and b - 1 = -.210; P =.0321) but was mass-independent at 5 degrees C. Pentose s hunt flux scaled negatively with anemone mass at 5 degrees C (b - 1 = -.063; P =.0124) but was mass-independent at 15 degrees C. Regression of glycolytic flux versus anemone mass was significant at 5 degrees C (b - 1 = -.052; P =.0218) but not at 15 degrees C, which was opposite the pattern observed for the glucose oxidation rate as these temperatu res. Therefore, glycolytic flux and the glucose oxidation rate scaled independently, The mass exponents for flux through these metabolic pat hways were similar to those for whole-anemone oxygen consumption rates in this species and to mass exponents for activities of enzymes assoc iated with aerobic metabolism in more complex animals.