Fig. 9

SEM photomicrographs of the ventral skin of the adult starry puffer fish showing: (a, b) Epidermal surface characterized by the presence of irregular-shaped protrusions (arrowheads) arranged in an erratic manner, odontic spines of symmetric heights (asterisks) emerging from hole-like sinuses (arrows). c, d High magnifications of the inner epithelial surface of the sinus. Note the corrugated folds (arrows), the mucous cell openings (arrowheads) with blobs of mucous on their margins, and the ill-defined deep epithelial cells (twisted arrows). e, f The epidermal surface of the irregular-shaped elevations was characterized by the presence of abundant mucous cell openings (arrowheads), superficial epithelial cells (barbed arrow), and a sensory cell (asterisk). g High magnification of the superficial epithelial cells (barbed arrow). Note the extensive concentrically organized microridges with ill-defined borders like ridges approximately as the fingerprint pattern. h High magnification of the epidermal surface between the elevations. Note the less frequently seen large mucous cell openings (arrowhead), and the deep epithelial cells with reduced or short microridges (barbed arrow)