FIGURE 4 in Vansoestia caribensis gen. nov., sp. nov.: first report of the family Ianthellidae (Verongida, Demospongiae) in the Caribbean

FIGURE 4. TEM sections of Vansoestia caribensis gen. nov. sp. nov. A. Roundish to ovoid Spherulous cells type 1 (Sc1) with nucleus (Nu) bearing round spherules containing light and dark inclusions, and abundant collagen fibrils (Co), Scale = 2.5 µm. B. Sperulous cell type 2 with electron dense dark granules, and bacteria within it, close to an aquiferous channel (Ac), Scale = 2 µm. Bacteria can be seen in the interior of the channel. C. Vacuolar cells (Sc 3) seen in the mesohyl close to an aquiferous channel, Scale = 2 µm. D. A microgranular cell (Mc) with striated membrane-bound bodies, among spherulous cells 1, and 2. Note the presence of abundant collagen fibrils (Co) between the cells, Scale = 1.3 µm. E. Portion of a choanocyte chamber where main body of the choanocytes can be seen, some with cytoplasmatic projections (Cy). A collagen fibril layer (Co) is found surrounding all choanocyte chambers, Scale = 1.6 µm. F. A triangular shaped choanocyte (Ch) with a basal nucleolated nucleus, contiguous to a layer of fibrillar collagen (Co) containing bacteria (Ba), Scale = 1.3 µm.