. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 204 PHILLIPS AND B. DUE. Figure 4. A sequence of videotape frames showing the capture of a 40-^m head by a swimming, sell- tethered Arctonoc vitlala larva. Time (seconds) is in the bottom left corner. All images are at the same magnification; the scalebar is 100 ^m. The larva is rotating around its anterior-posterior axis in a clockwise direction (when viewed from the anterior), and swimming towards the lower right of the image, (a) A bead approaches the larva's episphere. (b) The bead contacts the episphere. (c
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 204 PHILLIPS AND B. DUE. Figure 4. A sequence of videotape frames showing the capture of a 40-^m head by a swimming, sell- tethered Arctonoc vitlala larva. Time (seconds) is in the bottom left corner. All images are at the same magnification; the scalebar is 100 ^m. The larva is rotating around its anterior-posterior axis in a clockwise direction (when viewed from the anterior), and swimming towards the lower right of the image, (a) A bead approaches the larva's episphere. (b) The bead contacts the episphere. (c) The bead moves toward the upper lip (d) The larva recoils and the bead is disengaged from the episphere. (e-g) The larva begins to rotate again, carrying the bead in front of and slightly to the left of the mouth, (h) After one full revolution the bead is held in the mouth. (i)The head (as well as a previously captured bead) is visible in the gut. several transverse ciliary bands (Fig. la. b: Cazaux, 1968; Holborow, 1969; Lacalli, 1981). In larvae of A. nlkiia (and larvae of Huntioihoe iinhricutu: Holborow, 1969), the two bands located nearest to the episphere apex beat slowly and discontinuously; the band of cilia located be- tween the episphere apex and the mouth (the "akro- troch," Fig. la, b) beats rapidly and continuously in the direction of the mouth (Fernet, pers. obs.). These ciliary bands may act in feeding by sensing approaching parti- cles, distributing adhesive secretions over the episphere, or moving particles ventrally towards the mouth of the larva. After the particle had been moved ventrally on the episphere, the tethered larva recoiled rapidly and then continued rotating. This recoiling motion, presumably a consequence of a brief reversal of beat of the prototro- chal cilia, disengaged the particle from the region of the episphere, leaving it positioned about 80-90 ^m ventral to and slightly to the left of the mouth (Figs. 4d-e, 5d-e). As the larva
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
