. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 564 D. E. ALEXANDER AND J. GHIOLD CXJ _ _. B=± (DIFFERENCE FROM ) N=74 000 160 LOG TEST DIAMETER (MM) FIGURE 2. Length of the anal lunule measured against test length. Solid line is least- squares regression line, dashed line is line of isometry (see Fig. 1 for further explanation). Note slope confidence limits include were used. In long-term experiments individuals were marked by tying colored threads through the lunules and were positioned near the anchor of a float. By carefully r
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 564 D. E. ALEXANDER AND J. GHIOLD CXJ _ _. B=± (DIFFERENCE FROM ) N=74 000 160 LOG TEST DIAMETER (MM) FIGURE 2. Length of the anal lunule measured against test length. Solid line is least- squares regression line, dashed line is line of isometry (see Fig. 1 for further explanation). Note slope confidence limits include were used. In long-term experiments individuals were marked by tying colored threads through the lunules and were positioned near the anchor of a float. By carefully raking the sand around the float anchor where the animals were placed, over 90% of the organisms were recaptured routinely. The burrowing speed of each of five sand dollars was measured two times before and two times after the lunules were plugged. We found that the time it takes an uncovered sand dollar to become completely covered with sand is an excellent indicator of burrowing speed; thus, the burrowing time of several sand dollars was measured before and after plugging the lunules with soft paraffin. To determine whether the lunules are used in righting inverted sand dollars, 12 sand dollars were collected and half of them had their lunules plugged. The sand dollars were left inverted near the float anchor and observed at the next low tide (for unknown reasons, Mellita qtiinquicsperjorata will right itself in the field but not in the laboratory.) To test the importance of lunules in feeding, 24 sand dollars were collected from the area near the float anchor and tagged. Twelve had their lunules plugged with soft paraffin, and the remaining animals were used as controls. Each control individual was exposed to air for the length of time that it took to plug the lunules of an individual in the other group. All the animals were returned to the sand near the float anchor within a few meters of where they were collected. Two days later, the sand dollars were recaptured. Animals w
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
