. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 28. S. JOHNSEN ET AL Outer epithelium Figure 1. Photographs under artificial light of the deep-sea finned octopod Stauroteuthis syrtenxis with the wehhed arms in swimming pos- ture (A) and spread (B) displaying the photophores/suckers (arrowheads) that appear as white spheres along the length of the inner surface of the arms. The posture shown in (B) may he one of extreme withdrawal intended to startle intruders with the sudden appearance of hioluminescent suckers, ar, arm; ey, eye; fi, fin; wb, webbing between arms. Scale b
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 28. S. JOHNSEN ET AL Outer epithelium Figure 1. Photographs under artificial light of the deep-sea finned octopod Stauroteuthis syrtenxis with the wehhed arms in swimming pos- ture (A) and spread (B) displaying the photophores/suckers (arrowheads) that appear as white spheres along the length of the inner surface of the arms. The posture shown in (B) may he one of extreme withdrawal intended to startle intruders with the sudden appearance of hioluminescent suckers, ar, arm; ey, eye; fi, fin; wb, webbing between arms. Scale bars = 4 cm. (except possibly the very small ones at the tips of the arms) appeared capable of luminescence. No other portion of the body was observed to emit light. Morphology of photophores Each photophore is a raised papilla-like structure partially embedded in the connective tissue of the arm. The photo- phores are composed of three layers of cells: an outer epithelium modified to form a collar, infundibulum, and acetabulum: a capsule-like mass of muscle and neural tissue beneath the epithelium; and a thin layer separating the capsule from the dermis of the arm (Figs. 3, 4, 5). The collar epithelium is continuous with the epidermis and is folded inward, forming a rim around the central portion of the photophore (Figs. 3B, C; 4A). In both formalin- and glut- araldehyde-preserved specimens, the photophores appear to be either everted above (Fig. 3B) or retracted below (Fig. 3C) the outer edge of the collar. The outer and inner folds of the collar epithelium are morphologically distinct and are different from the epider- mis covering the arm (Figs. 5, 6). The epidermis of the arm is squamous to cuboidal in character and consists of epithe- lial cells possessing scattered apical microvilli (Fig. 6A). The outer edge of the collar is composed of columnar cells with apical microvilli, numerous electron-lucent and elec- tron-dense vesicles, and large, apically placed, elongated nucl
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
