. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THE LUMINESCENCE OF LUMINODESMUS 121 by 20 to 40 per cent (or occasionally more) around a relatively constant mean. Since these light intensity changes could be detected with the eye, we are certain that they do not result from movements of the animal. A two-hour portion from such a recording is reproduced in Figure 1A. It can be seen that there is an instance when the light intensity doubled, apparently spontaneously. Such a marked increase in light intensity also occurs when the animal is handled. Indeed we found that stri
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THE LUMINESCENCE OF LUMINODESMUS 121 by 20 to 40 per cent (or occasionally more) around a relatively constant mean. Since these light intensity changes could be detected with the eye, we are certain that they do not result from movements of the animal. A two-hour portion from such a recording is reproduced in Figure 1A. It can be seen that there is an instance when the light intensity doubled, apparently spontaneously. Such a marked increase in light intensity also occurs when the animal is handled. Indeed we found that striking the test tube in which the animal was placed would evoke such a re- sponse (Fig. IB). The response still occurred immediately after the animal had been decapitated. Upon stimulation of the nerve cord which induced electrical shocks no luminescent response was observed which could be attributed to the effect of the electrical stimuli. The way in which the luminescent changes are brought about in the living animal is not clear. \ \. FIGURE 1. Reproductions of recordings of Luminodesmus luminescence. Ordinate, light intensity; abscissa, time, to be read from right to left in both cases. Left: Luminescence of an undisturbed animal over a two-hour interval. Time between vertical divisions, 15 minutes. Right: Luminescence changes of an animal where the test tube containing the animal was tapped lightly at the two instances noted by arrows. Time between vertical divisions, one minute. Isolated pieces of the animal retain their luminescence for a long time. The intensity decreases gradually to about one half of its original value in 8 hours. Although fluctuations in intensity may occur for the first 15 minutes, it is essentially a steady luminescence thereafter. An eviscerated specimen from which the first few and last few segments are cut off behaves in essentially the same manner. Animals removed from humus and kept in a test tube for a day or more also showed little fluctuation
Size: 2569px × 973px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
