. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 414 V. M. WEIS ET FIGURE 8. Reconstruction of nerve layer below a mucous cell. Neurites extend in both directions. Some contain microtubules. while others contain neurosecretory granules. Labels as in previous figures. in cnidarian planulae, modified from Martin and Thomas (1977), is presented in Table I. Nematocytes, not studied in depth in many planulae, appear to have the same general cell structure as those described in adult hydroids ( Chapman and Tilney, 1959; Slautterback and Fawcett, 1959; Lentz, 1966, and
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 414 V. M. WEIS ET FIGURE 8. Reconstruction of nerve layer below a mucous cell. Neurites extend in both directions. Some contain microtubules. while others contain neurosecretory granules. Labels as in previous figures. in cnidarian planulae, modified from Martin and Thomas (1977), is presented in Table I. Nematocytes, not studied in depth in many planulae, appear to have the same general cell structure as those described in adult hydroids ( Chapman and Tilney, 1959; Slautterback and Fawcett, 1959; Lentz, 1966, and many others), but with different nematocysts. The supportive cell or EMC of H. echinata very closely resembles that of the hydroids Pennaria tiarella (Martin and Thomas, 1977) and Mitrocomellapolydiademata (Martin et a/., 1983) in both cell structure and content. All three extend from the mesoglea to the ectoderm and contain locomotory cilia. The EMCs of P. tiarella planulae, as in H. echinata, contain dense, membrane- bound granules at their apex, whereas M. polydiademata lacks apical granules and possesses large basal ones. Mitrocomella polydiademata, however, does possess a cell containing dense staining granules which may also be a supportive cell. In contrast to these hydroids, the supportive cells of the four described anthozoan planulae all lack dark-staining granules. The cilia of supportive cells in Balanophyllia regia (Lyons, 1973), Pocillopora damicornis (Vandermeulen, 1974), and Anthopleura elegantissima (Chia and Koss, 1979) all contain collar cells consisting of an ordered, symmetrical arrangement of microvilli around the cilium and complex bands of microfilaments associated with the striated rootlet of the cilium. No such apparatus is found in H. echinata or other described hydroid planulae. The mucous cell of H. echinata is also very similar to mucous cells found in P. tiarella and M. polydiademata, except that these hydroids lack the concavity for the cilium an
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
