Abstract
The optic cushion of Nepanthia belcheri (Perrier) is a prominent pigmented sense organ situated on the oral surface below the terminal tentacle. The distal region contains up to 170 optic cups, whilst proximally are numerous pyriform glandular cells traversed by supporting fibres. The outer margin of the optic cup is formed by alternating pigmented and photoreceptor cells. The pigmented cells contain numerous densely staining granules of scarlet pigment. The distal ends of the photoreceptors are elaborated into many long microvilli regularly arranged about a modified cilium. There is a clear circumciliary space delimiting the cilium from the microvilli.
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Literature Cited
Castilla, J. C.: Responses to light of Asterias rubens L. Proc. 4th Eur. mar. Biol. Symp. 4, 495–511 (1971) (Ed. by D. J. Crisp. Cambridge: Cambridge University Press)
Cobb, J. L. S.: The significance of the radial nerve cords in asteroids and echinoids. Z. Zellforsch. mikrosk. Anat. 108, 457–474 (1970)
Dorsett, D. A. and R. Hyde: The fine structure of the lens and photoreceptors of Nereis virens. Z. Zellforsch. mikrosk. Anat. 85, 243–255 (1968)
Eakin, R. M.: Line of evolution of photoreceptors. In: General physiology of cell specialization, pp 393–425. Ed. by D. Mazia A. Tyler. New York: McGraw-Hill Book Co. 1963
Eakin, R. M.: Evolution of photoreceptors. Cold Spring Harb. Symp. quant. Biol. 30, 363–370 (1966)
Eakin, R. M.: Structure of invertebrate photoreceptors. In: Handbook of sensory physiology, Vol VII/1. pp 626–683. Ed. by H. J. A. Darnall. Berlin: Springer-Verlag 1972
Eakin, R. M. and J. L. Brandenburger: Differentiation in the eye of a pulmonate snail, Helix aspersa. J. Ultrastruct. Res. 18, 391–421 (1967)
Eakin, R. M. and J. A. Westfall: Fine structure of photoreceptors in the hydromedusan, Polyorchis penicillatus. Proc. natn. Acad. Sci. U.S.A. 48, 826–833 (1962)
Eakin, R. M. and J. A. Westfall: Electron microscopy of photoreceptors in two species of Onychophora. Am. Zool. 4, p. 434 (1964)
Engster, M. S. and S. C. Brown: Histology and ultrastructure of the tube foot epithelium in the phanerozonian starfish, Astropecten. Tissue Cell 4, 503–518 (1972)
Hartline, H. K., H. G. Wagner and E. F. MacNichol: The peripheral origin of nervous activity in the visual system. Cold Spring Harb. Symp. quant. Biol. 17, 125–141 (1952)
Hermans, C. O. and R. M. Eakin: Fine structure of the cerebral ocelli of a sipunculid, Phascolosoma agassizii. Z. Zellforsch. mikrosk. Anat. 100, 325–339 (1969)
Hyman, L. H.: The invertebrates: Echinodermata. Vol. 4. i–vii +763 pp. New York: McGraw-Hill Book Co. 1955
Kawaguti, S.: Electron microscopy of the radial nerve of a starfish. Biol. J. Okayama Univ. 11, 41–52 (1965)
Kawaguti, S., Y. Kamishima and K. Kobashi: Electron microscopy on the radial nerve of the sea-urchin. Biol. J. Okayama Univ. 11, 87–95 (1965)
Millott, N. and H. G. Vevers: Carotenoid pigments in the optic cushion of Marthasterias glacialis (L.). J. mar. biol. Ass. U.K. 34, 279–287 (1955)
Reese, E. S.: The complex behaviour of echinoderms. In: Physiology of Echinodermata, pp 157–218. Ed. by R. A. Boolootian. New York: John Wiley & Sons, Inc. 1966
Smith, J. E.: On the nervous system of the starfish Marthasterias glacialis (L.). Phil. Trans. R. Soc. (Ser. B) 227, 111–173 (1937)
Smith, J. E.: Echinodermata. In: Structure and function in the nervous systems of invertebrates. Vol. 2. pp 1519–1558. Ed. by T. H. Bullock and G. A. Horridge. San Francisco: W. H. Freeman & Co. 1965
Spurr, A. R.: A low-viscosity epoxy resin embedding medium for electron microscopy. J. Ultrastruct. Res. 26, 31–43 (1969)
Vaupel von Harnack, M.: Über den Feinbau des Nervensystems des Seesternes (Asterias rubens L.). III. Mitteilung. Über die Struktur der Augenpolster. Z. Zellforsch. mikrosk. Anat. 60, 432–451 (1963)
Yoshida, M.: Photosensitivity. In: Physiology of Echnodermata, pp 435–464. Ed. by R. A. Boolootian. New York: John Wiley & Sons, Inc. 1966
Yoshida, M. and H. Ohtsuki: Compound ocellus of a starfish: its function. Science, N.Y. 153, 197–198 (1966)
Yoshida, M. and H. Ohtsuki: The phototactic behaviour of the starfish, Asterias amurensis Lutken. Biol. Bull. mar. biol. Lab., Woods Hole 134, 516–532 (1968)
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Communicated by G. F. Humphrey, Sydney
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Penn, P.E., Alexander, C.G. Fine structure of the optic cusion in the asteroid Nepanthia belcheri . Marine Biology 58, 251–256 (1980). https://doi.org/10.1007/BF00390773
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DOI: https://doi.org/10.1007/BF00390773