THE HORMONAL CONTROL OF METABOLISM IN CRUSTACEANS. IX. CARBOHYDRATE METABOLISM IN THE TRANSITION FROM INTERMOULT TO PREMOULT IN CARCINIDES MAENAS

¹ Department of Biology, University of Oregon, Eugene, Oregon, and Laboratoire Arago, Banyuls-sur-Mer

1. A laboratory population of Carcinides maenas was sampled three times over period of 70 days, and the blood carbohydrate, blood lipochromes, total body carbohydrate, total body polysaccharide, non-protein nitrogen, and ammonia nitrogen were determined; the effect of eyestalk removal on these quantities was also examined.

2. During the course of the observations, there was a progression within the population from late intermoult (C₄) to early premoult (D) stages.

3. The change from intermoult to premoult was signalized by the appearance of relatively large amounts of lipochromes in the blood and integument, and by an increase in total body carbohydrate content. These biochemical changes preceded any morphological signs of preparation for moult.

4. Eyestalk extirpation caused an increase in the body carbohydrate, but did not alter the blood lipochromes. The increase in carbohydrate was observed only in those animals which had not undergone the change spontaneously.

5. The other quantities measured showed no variation attributable either to the stage in the intermoult cycle or to eyestalk removal.

6. The results are discussed with relation to the possible mechanisms of the effects observed, and the hormonal factors concerned.