Endocrine regulation of carbohydrate metabolism during the moult cycle in crustaceans I. Effect of eyestalk removal in Ocypoda platytarsis

The endocrine regulation of carbohydrate metabolism in the decapod Ocypoda platytarsis was investigated by eyestalk ablation at all stages of the moult cycle. Eyestalk removal (and hence removal of a substance probably produced by it) profoundly influences the carbohydrate level of the major storage organ, the hepatopancreas. The changes taking place storage organ, the hepatopancreas. The changes taking place in hepatopancreatic glycogen are reflected in the blood sugar (glycemic) level. The blood-sugar level is also related to dynamic events taking place in the cuticle during the moult cycle. At the intermoult and postmoult stages, the eyestalk factor directs the sugar supply for energy metabolism, and prevents sugar deposition as glycogen in the hepatopancreas. At the premoult stage, the activity of the eyestalk is suppressed by the moulting gland (the Y organ), as eyestalk ablation does not alter the blood-sugar value or the hepatopancreatic glycogen-level. After the increase at the freshmoult stage due to eyestalk ablation, the blood-sugar level tends to re-attain its previous low level at the postmoult stage.