Intact Luidia clathrata (Say) and individuals with two adjacent arms amputated were fed on a maintenance-level diet or starved for 3 months during the gametogenic period. The radius of the intact arms did not change significantly in any of the groups. The radius and the amount (g dry weight) of regenerating arms of fed individuals were 3- to 4-fold as great as those of starved individuals. The amount of pyloric caeca and gonad in an intact arm increased in fed individuals and the amount of pyloric caeca decreased in starved ones independently of regeneration. The amount of pyloric caeca in an intact arm increased more in fed, regenerating individuals than in fed, intact individuals; the total amount of increase in the pyloric caeca was equivalent in the two groups. Absorbed nutrients are allocated primarily to growth of the pyloric caeca and gonads of the intact arms and secondarily to regeneration. This increase in functional capacity in terms of nutrient storage (pyloric caeca) and reproduction (gonads) may be more important than an increase in capacity for locomotion. © 1986.