. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 302 M. SA1GUSA ET AL. •* oh Figure 11. Time course of the dissociation of the investment coat from the ovigerous hair. Clusters of embryos were incubated with crude, concentrated hatch water for 2 min (A), 4 min (B), 10 min (C). and 120 min (D). Ela and Elb: sublayers of the investment coat, oh: ovigerous hair. «l and a2: surface layers of the hair. Arrows: tubules (tu). Note that the extensions of the sublayer Ela retract, but electron-dense sites remain in the surface of the al layer of the ovigerous hair (upward arrowhead
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 302 M. SA1GUSA ET AL. •* oh Figure 11. Time course of the dissociation of the investment coat from the ovigerous hair. Clusters of embryos were incubated with crude, concentrated hatch water for 2 min (A), 4 min (B), 10 min (C). and 120 min (D). Ela and Elb: sublayers of the investment coat, oh: ovigerous hair. «l and a2: surface layers of the hair. Arrows: tubules (tu). Note that the extensions of the sublayer Ela retract, but electron-dense sites remain in the surface of the al layer of the ovigerous hair (upward arrowheads in C and D). Scales are all 100 nm. Figs. 2A and 6E). We speculate that the kneading of the egg cluster by the ovigerous setae was not fully transferred to the donated setal segment, so the investment coat and fu- niculus were incomplete. Disposal of the embryo attachment svstem after hatching The outermost layer of the egg envelope (Ela) attaches to the ovigerous hair (Fig. 4). Moreover, electron-dense, slen- der structures arranged at intervals of 130-160 nm around the hair seem to be involved in attachment. Figure 11A shows a section of a hair in an investment coat; the hair was treated with crude, concentrated hatch water and fixed 2 min later. The sublayer Ela is still adhering to the ovigerous hair through its ridges. In a section of a hair fixed 4 min after the treatment with hatch water (Fig. 11B). the space between the hair and the envelope has become slightly wider, but the connection between the hair and the ridges of Ela still remain. Note, however, that some of the ridges on Ela seem to be dissociating from a structure that remains on the hair. After 10 min of treatment with hatch water, the envelope was completely detached from the hair, and the dissociation of the ridges of Ela from the structures on the hair has advanced (Fig. 11C). Two hours after treatment (Fig. 1 ID), the space was widely expanded, and the ovigerous hair easily slipped out of the coat, w
Size: 1903px × 1313px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
