. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. WHITE CHROMATOPHORES 609 5 - UJ CC Q_ O 2 2 O cr x u. 60 MINUTES 120 FIGURE 2. Responses of the white chromatophores of Uca pugilator to a change of back- ground. Crabs changed from a black background to white (dots), from a white background to black (circles). ground the pigment was almost maximally dispersed. These results show that in Uca pugilator from Panacea, Florida, the background response overrides the daily rhythm at this intensity of incident illumination. Time required to achieve maximal chromatic adaptation Twen
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. WHITE CHROMATOPHORES 609 5 - UJ CC Q_ O 2 2 O cr x u. 60 MINUTES 120 FIGURE 2. Responses of the white chromatophores of Uca pugilator to a change of back- ground. Crabs changed from a black background to white (dots), from a white background to black (circles). ground the pigment was almost maximally dispersed. These results show that in Uca pugilator from Panacea, Florida, the background response overrides the daily rhythm at this intensity of incident illumination. Time required to achieve maximal chromatic adaptation Twenty specimens of Uca pugilator were taken from the stock aquaria and divided into two groups of 10 crahs each. One group was placed in a white enameled basin and the second group in a black enameled basin. At 9 AM both containers were placed under an illumination of meter-candles light intensity. At 11 AM the average stage of the white chromatophores in the crabs from each pan was determined. The crabs that had been on a white background were then placed on a black background and vice versa. The chromatophore stages of the crabs in each basin were subsequently determined 15, 30, 60, 90 and 120 minutes after the backgrounds had been interchanged. This experiment was repeated once and the averaged data were used in the preparation of Figure 2. As is evident from the figure, the white pigment of crabs on a black background became maximally concen- trated. On a white background the white pigment was nearly maximally dispersed. Background adaptation was complete in two hours. The chromatophore stages of the crabs adapted to these backgrounds are essentially the same as seen in Figure 1 for the crabs on the same backgrounds. Relationships between chromatophore stage and incident light intensity Ten crabs were placed into each of seven black and seven white basins at 8:30 AM. The crabs in one black and one white container were then exposed. Please note that these images are extrac
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
