THE EFFECTS OF TEMPERATURE CHANGES UPON THE CHROMATOPHORES OF CRUSTACEANS

¹ From the Harvard Biological Station, Soledad, Cienfuegos, Cuba and the Zoölogical Laboratory, Harvard University

1. Expansion of the chromatophores of Macrobrachium acanhturus, a Cuban shrimp, follows immersion of these animals in fresh water at any temperature between 6° and 15° C. or between 35° and 40° C. This reaction occurs regardless of the background upon which the shrimp is placed. Between 15° C. and 35° C. the chromatophores of this shrimp expand when the animal is placed upon a black background and contract when the animal is placed upon a white background.

2. In blinded and chloretonized shrimps, the chromatophores are expanded and this expansion is in no way altered by changes in background or temperature.

3. Neither high nor low temperatures have any effect upon the potency or manufacture of the chromatophore-contracting substance elaborated by the eye stalks.