. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOKINES1S IN SPONGE LARVAE 331. Figure 6. The structure and ultrastructure of Reneira sp. larvae (a, b: light microscopy; c-f: electron microscopy), (a) A longitudinal section through a 2-h-old larva shows that short (20-/xm-long) lateral cilia (SLC) arise from columnar epithelial cells (CEC) except at the anterior pole (AP) and posterior pole (PP), which are bare. Long posterior cilia (LPC) arise from pigment-tilled columnar epithelial cells primarily in the anterior portion of the pigment ring (PRg). Inside the CECs is
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOKINES1S IN SPONGE LARVAE 331. Figure 6. The structure and ultrastructure of Reneira sp. larvae (a, b: light microscopy; c-f: electron microscopy), (a) A longitudinal section through a 2-h-old larva shows that short (20-/xm-long) lateral cilia (SLC) arise from columnar epithelial cells (CEC) except at the anterior pole (AP) and posterior pole (PP), which are bare. Long posterior cilia (LPC) arise from pigment-tilled columnar epithelial cells primarily in the anterior portion of the pigment ring (PRg). Inside the CECs is a layer of subepithelial cells (SECl that run circumfer- entially around the larva. Cells in the central region (inner cell mass, ICM) are aligned along the anterior- posterior axis of the larva. Spicules (sp) are evident at the posterior pole. The region in the box is shown in (c). Bar a. b: 100 /xm. (b) A tangential longitudinal section through the edge of a 2-h-old larva shows that the subepithelial cells (SEC) are aligned perpendicular to the A-P axis of the larva. The region in the box is shown in (f). Pigment ring, PRg. (c) Columnar epithelial cells from the region of the larva shown in the box in (a): mitochondria, m: mucous cell, me: basal body of the cilia, bb; nucleus, m light inclusions, li. Bar: 4 /Mm. (d) Flask-shaped epithelial cells that occur towards the anterior end of the larva possess a large centrally located nucleus (n) and a cilium that arises from a deep invagination in the cell (arrowheads). Bar: 2 (e) Cells of the inner cell mass. Spicules. sp; nucleus, n; extracellular rod-shaped bacteria, b (inset). Bar: 5 /^m; inset: 2 (f) Subepithelial cells (SEC) from the region shown in the box in (b) lie in a dense bed of collagen (co). Light inclusions (li) can be seen in the bases of the columnar epithelial cells (CEC). Bar: 10 /j, Please note that these images are extracted from scanned page images that may have been digitally enhanced for reada
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
