. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 28 S. AMANO AND I. HORI >' "•• p. Figure 17. Immature choanocytes (C) of the juvenile sponge of Lcucuxulcniii lu.\ti about 36 h after settlement. G: glutinous granule. P: pinucoderm. Scale bar = 2 /MTU. Figure 18. Choanoderm of the juvenile sponge of Leucosolenia la.\a about 72 h after settlement. A: autophagosome. C: collar. F: flagellum of a choanocyte. N: nucleus, P: pmacoderm. Scale bar = 2 /urn. The flagellated cells are arranged in a pseudostratified layer in a swimming larva. This cell layer is not a true epit
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 28 S. AMANO AND I. HORI >' "•• p. Figure 17. Immature choanocytes (C) of the juvenile sponge of Lcucuxulcniii lu.\ti about 36 h after settlement. G: glutinous granule. P: pinucoderm. Scale bar = 2 /MTU. Figure 18. Choanoderm of the juvenile sponge of Leucosolenia la.\a about 72 h after settlement. A: autophagosome. C: collar. F: flagellum of a choanocyte. N: nucleus, P: pmacoderm. Scale bar = 2 /urn. The flagellated cells are arranged in a pseudostratified layer in a swimming larva. This cell layer is not a true epithelium because—like similar layers in other sponges—it lacks a basal lamina (Gaino et ai, 1985: Woollacott and Pinto, 1995). One flagellum emerges from the flat outer surface of the cell. In most sponges, however, larval flagella emerge from a pit at an outer surface (Amano and Hori. 1992, 1994: Woollacott, 1993: Woollacott and Pinto, 1995). After set- tlement, the flagellated cells soon loose their flagellum and dedifferentiate. The dedifferentiation is apparently triggered by the settlement of the larva. Autophagosomes play a central role in the intracellular processes of dedifferentia- tion. These autophagosomes are different in origin and structure from the phagosome-like granules in the basal cytoplasm of the larval flagellated cells: the latter were probably formed to take in nutritive materials by phagocy- tosis during ovogenesis (Fell. 1969): the former are formed de novo after settlement and are usually larger than the latter. Glutinous granules, fibrous yolk granules, and basal rootlets in various stages of digestion are observed in the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annua
Size: 1551px × 1612px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
