Fig. 4

Putative secretory cell types in the basal tissue of E. pallida. a 3view serial block-face image and (b) rendered 3D isosurface of cell types i – iv (excluding ii, in this image) in the ectoderm of the pedal disc. Cell type i is seen as two variations. One full (blue) vs granular (red). The outer layer of microvilli is also present. n = nematocyst. g = granules. v = villi. c-g TEM images of cell types i-iv. n = nematocyst, v = villi, g = granules. c High concentration of cell type i and cell type ii in the column of the animal (d) cell type ii from the pedal disc. e Cell type iii containing distinct vesicles, commonly found in the pedal disc. f Cell type iv with small, distinct circular vesicles from the pedal disc. g High magnification TEM of the electron dense granular band that runs adjacent and in parallel with the external membrane. Scale bars: (a) 2 μm, (c) 2 μm, (d) 2 μm, (e) 500 nm, (f) 1 μm, (g) 200 nm