THE CHROMATOPHOROTROPIC HORMONE OF THE CRUSTACEA: STANDARDIZATION, PROPERTIES AND PHYSIOLOGY OF THE EYE-STALK GLANDS

Abstract

A method for the standardization of the crustacean eye-stalk horpione on the blinded fiddler crab, Uca, is descr. The Uca unit is defined as the amount of hormone contained in 1 cc. of solution, 0.05 cc. of which when injected into each of 15 specimens of U. pugilator blinded 2 days previously produces a response whose average duration is about 5.0 hrs. The response is measured as the amount of time intervening between the injection of the hormone and the time at which the animals again become pale, an interval during which the melanophores expand, remain expanded for some time, and finally contract. The hormone content in the eye-stalks of various crustaceans was detd. A method for the extraction and purification of the hormone is described, and some chem. and physical properties of the hormone are listed. The amount of hormone extracted from the eye-stalks of Palaemonetes is the same regardless of whether the hormone is secreted continuously into the circulation, or whether it is continuously absent, conditions which are brought about by illuminated white and black surroundings respectively. In darkness, there is no release of the hormone into the blood, and a very low content of hormone in the eye-stalks, approximately half that obtained from the stalks of illuminated animals. It is postulated that light, regardless of background, causes an acceleration in hormone synthesis, and that light depending on certain backgrounds, such as white, causes a maximal release of the hormone into the circulation with a concomitant increase in rate of production of the hormone. The diurnal color rhythm of Uca is an external expression of a diurnal release of the hormone into the circulation. Both release and synthesis are independent of environmental conditions, and it is suggested that they are controlled by a diurnal discharge of nerve impulses from the C. N. S. This discharge, during the day, would exert a. 12-hour release of the hormone with a concomitant increased rate in production, the absence of the discharge during night would cut off release and slow down rate of synthesis.