. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 18 M. W. HART. Figure 6. A cartoon of the particle capture sequence shown in Figure 5. The positions of the sphere in each panel of Figure 5 are indicated by the dots, and the particle path between these positions is interpolated by the solid line. The ciliated band of the larva is shown by the heavy lines; the mouth and stomach are shown in outline. toward the observer and videocamera, capturing spheres as they swam. Runnstrom (1918) described this and a variety of other swimming postures; I observed some of them (most nota
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 18 M. W. HART. Figure 6. A cartoon of the particle capture sequence shown in Figure 5. The positions of the sphere in each panel of Figure 5 are indicated by the dots, and the particle path between these positions is interpolated by the solid line. The ciliated band of the larva is shown by the heavy lines; the mouth and stomach are shown in outline. toward the observer and videocamera, capturing spheres as they swam. Runnstrom (1918) described this and a variety of other swimming postures; I observed some of them (most notably a lateral swimming direction, usually with the ventral side uppermost, as the larva swam slowly along the bottom of the chamber). These alternative swimming patterns were usually associated with low rates of feeding and frequent general ciliary arrests during which the larva came to a halt on the chamber bottom. I am not sure whether these behaviors are likely to be common in the plankton. The aborally directed beat of cilia on the ciliated band produces water currents with a net posterior component that drives the larva forward while moving water laden with particles toward the ciliated band. Polystyrene spheres entrained in these currents approached the ciliated band on the upstream side of the band (usually on the arms of plutei, or on the loops of band between the bases of the arms, and on the anterior, posterior, and lateral portions of the band on bipinnariae and auriculariae). In cases where the proximity of the particle to the ciliated band could be judged, spheres appeared to approach within about one diameter of the surface of the larva (10- 20 ^m), less than the length of the cilia on most parts of the ciliated band (20-30 ^m; Strathmann, 1971; Mc- Edward, 1984). For larvae that were actively feeding, spheres approached the ciliated band, then abruptly changed direction at the band, and moved back toward the circumoral field rather than passing over the band towa
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
