. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 248 BRUCE L. UMMINGER are employed. However, since intensities are normally constant at midday in nature, the rhythm probably persists under natural conditions. DISCUSSION Ecological significance From the experiments with Cyclops vcniulis it is clear that experimental con- ditions including unpolarized light at constant intensity in all directions at all times of day are highly artificial. Extremely interesting patterns of behavior that would never occur under such highly artificial light regimes are elicited when certain as
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 248 BRUCE L. UMMINGER are employed. However, since intensities are normally constant at midday in nature, the rhythm probably persists under natural conditions. DISCUSSION Ecological significance From the experiments with Cyclops vcniulis it is clear that experimental con- ditions including unpolarized light at constant intensity in all directions at all times of day are highly artificial. Extremely interesting patterns of behavior that would never occur under such highly artificial light regimes are elicited when certain aspects of natural conditions of illumination are simulated, even 0-1 HR 5'/.-6'/«HR 11-12 HR INCREASE CONSTANT DECREASE. FIGURE 4. Summary of experiments using horizontally polarized light at different times of the 12-hour light cycle. Method of diagramming is same as in Figure 2. INCREASE, CONSTANT and DECREASE describe change in light intensity. CONTRAST describes intensity distribution found at the SURFACE of water. UNIFORM describes intensity dis- tribution in DEEP WATER. crudely. In order to understand the ecological significance of the various be- havioral reactions of Cyclops vcnialis to light, the various parameters of the experimental illumination must be given a natural interpretation. In this study, a horizontal polarization of light along all lines of sight was used to approximate the simplest of natural patterns of polarization in the aquatic habitat. It must be emphasized that this is a pattern that occurs only in low latitudes around noon. Increasing intensities of light were used to simulate conditions occurring during the early morning hours whereas decreasing intensities were used to approximate the conditions of illumination at dusk; constant inten- sities were used to represent conditions at midday. The effects of depth on light. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - color
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
