AN ANALYSIS OF CELL GROWTH AND METABOLISM IN THE CRAYFISH (PROCAMBARUS ALLENI)

¹ Department of Zoology, Washington University, St. Louis, Missouri

1. The resting metabolism of Procambarus alleni was determined over about a 4000-fold weight range. Metabolic rate was found to vary directly as the body weight raised to the – 0.24 power.

2. Abdominal muscle fiber diameters were determined over about a 4000-fold weight range. Calculated surface concentration was found to vary directly as the body weight raised to the – 0.22 power, providing evidence that the growth of the skeletal muscle is characterized by simultaneous addition and enlargement of fibers throughout the weight range.

3. Allometric analyses were made of fiber diameter, eye diameter, and ommatidia size with respect to the cube root of the body weight. The analyses indicated that the growth of the eye with respect to its constituent units is quantitatively similar to the growth of the abdomen with respect to its skeletal muscle cells.

4. The close similarity between the allometric coefficients of metabolic rate and surface concentration was taken as evidence that the metabolic rate of the whole animal may be dependent on the cell surface of the skeletal muscle.

5. Evidence obtained from the literature was cited for other examples of the growth of arthropod tissues by cell enlargement.