. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEA URCHIN MADREPORITE FUNCTION 437. Figure 13. Diagram of the madreporite region. A, axial organ; C, perivisceral coelom; H, head process of axial organ; M. madreporite; O. opening near the upper end of stone canal, between the region of confluence of the pore canals (suh-madreporite ampulla) and the axial sinus; R. rectum; T, test; AN, anus; PO, madreporite pore canal openings. Results Uptake of fluorescent microbeads As was observed in previous studies on asteroids and ophiuroids (Ferguson, 1990b, 1995), microbeads were t
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEA URCHIN MADREPORITE FUNCTION 437. Figure 13. Diagram of the madreporite region. A, axial organ; C, perivisceral coelom; H, head process of axial organ; M. madreporite; O. opening near the upper end of stone canal, between the region of confluence of the pore canals (suh-madreporite ampulla) and the axial sinus; R. rectum; T, test; AN, anus; PO, madreporite pore canal openings. Results Uptake of fluorescent microbeads As was observed in previous studies on asteroids and ophiuroids (Ferguson, 1990b, 1995), microbeads were taken up extensively into the exposed epidermis of the two urchins examined. Substantial numbers were also found within the water vascular system, especially in the madreporite and stone canal (Figs. 1-12). Figure 13 provides a diagrammatic orientation to the madrepor- ite region of the body. In the madreporite, some beads were seen in the lumen of the outer passages of the fine pore canals, and some within the pore cells, most con- centrated in their apical portion (Figs. 1-3). In the mid- region of the canals, numerous beads were found throughout the pore cells (Figs. 3-5). At the lower end of the pore canals, the abundance of beads retained di- minished markedly as the canals extended towards the region of their confluence (, the sub-madreporite ampulla) and the stone canal beyond (Figs. 5, 6). In the stone canal itself, a thick stringlike aggregate of beads and perhaps other material extended down the lumen (Figs. 7, 8). A few beads were also seen in the upper axial organ (Fig. 7), in the lumen of the rectum (found at- tached to the madreporite pieces that were sectioned), and in the peritoneum (or coelomocytes) near the rec- tum (Figs. 9, 10). Some beads were found in the lumen of tube feet, especially in the lower (oral) region of the body (Figs. 11, 12), but they were not plentiful. Many, perhaps most, tube foot sections failed to reveal any beads in the lumen. Figure
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
