. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VERTICAL MIGRATION OF ACARTIA TONSA 121 and in the dark. The cylinders were divided into sixths numbered from top to bottom. The average distance moved per hour was measured in units representing one-sixth of a cylinder (Table IV, Fig. 7A). The average behavior of the entire group gives the same results as before, but the individuals are seen to be continually moving. Each animal traverses about one-third of a cylinder (14-15 cm.) every hour. Maxi- mum movement occurs two hours after the lighting is changed. Too 0 4 6 8 10 1
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VERTICAL MIGRATION OF ACARTIA TONSA 121 and in the dark. The cylinders were divided into sixths numbered from top to bottom. The average distance moved per hour was measured in units representing one-sixth of a cylinder (Table IV, Fig. 7A). The average behavior of the entire group gives the same results as before, but the individuals are seen to be continually moving. Each animal traverses about one-third of a cylinder (14-15 cm.) every hour. Maxi- mum movement occurs two hours after the lighting is changed. Too 0 4 6 8 10 14 TIME IN HOURS. FIG. 7. A, average movements of 42 individuals. Ordinate, activity in units representing one-sixth of a cylinder ; abscissa, time in hours. B, Positions of two males. C , Positions of 2 females. Ordinate, position of animals in sixths of cylin- ders, numbered from top to bottom ; abscissa, time jn hours ; Bt indicates resting on bottom; OB indicates daylight fluorescent, oblique; Of. 25-watt. overhead. few males were present to permit a statistical comparison of the sexes, but no significant differences are found between the records of individ- ual males and females (Fig. 7). Because of the greater distances covered, the proportion of these scattered movements to the entire migra- tion may not be as great in nature as in the laboratory. These diverse movements suggest why field observations do not show that all of the animals are right on the surface at night, and down on the bottom during the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-1983. Woods Hole, Mass. :
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
