Summary
The median ocellus of Limulus consists of irregular groups of large photoreceptor cells which form a cup-shaped retina around the ocellar lens. Each group is surrounded and penetrated by guanophores and glia. The photoreceptor cells have extensive rhabdomeric regions, both along infoldings of cell membranes and between cells. Five-layered junctions occur between rhabdomeric microvilli. An occasional arhabdomeric (AR) cell is associated with a group of photoreceptors. Fine dendritic branches of the AR cell penetrate the rhabdomeric regions and form five-layered junctions with photoreceptor rhabdomeres. Axons of photoreceptor cells, and of at least some AR cells, gather at the proximal side of the cup to form an optic nerve.
Similar content being viewed by others
References
Bennett, M. V. L., Pappas, G. D., Gimenez, M., Nakajima, Y.: Physiology and ultrastructure of electrotonic junctions. IV. Medullary electromotor nuclei in gymnotid fish. J. Neurophysiol. 30, 236–300 (1967).
Clark, A. W., Millecchia, R., Mauro, A.: The ventral photoreceptor cells of Limulus. I. The microanatomy. J. gen. Physiol. 54, 289–309 (1969).
Demoll, R.: Die Augen von Limulus. Zool. Jb. Abt. Anat. u. Ontog. 38, 443–464 (1914).
Fahrenbach, W. H.: The morphology of the eyes of Limulus. I. Cornea and epidermis of the compound eye. Z. Zellforsch. 87, 278–291 (1968).
—: The morphology of the eyes of Limulus. II Ommatidia of the compound eye. Z. Zellforsch. 93, 451–483 (1969).
—: The morphology of the Limulus visual system. III. The lateral rudimentary eye. Z. Zellforsch. 105, 303–316 (1970).
Frank, R., Becker, M. C.: Microelectrodes for recording and stimulation. In: Physical techniques in Biological Research, vol. 5, W. L. Nastuk, ed. New York: Academic Press 1964.
Kaneko, A., Hashimoto, H.: Recording site of the single cone response determined by an electrode marking technique. Vision Res. 7, 847–851 (1967).
Kleinholz, L. H.: Purines and pteridines from the reflecting pigment of the arthropod retina Biol. Bull. 116, 125–135 (1959).
Lankester, E. R., Bourne, A. G.: The minute structure of the lateral and the central eyes of Scorpio and Limulus. Quart. J. micr. Sci. 23, 177–212 (1883).
Lasansky, A.: Cell junctions in ommatidia of Limulus. J. Cell Biol. 33, 365–384 (1967).
Miller, W. H.: Morphology of the ommatidia of the compound eye of Limulus. J. biophys. biochem. Cytol. 3, 421–127 (1957).
Nolte, J., Brown, J. E.: The spectral sensitivities of single cells in the median ocellus of Limulus. J. gen. Physiol. 54, 636–649 (1969).
—: The spectral sensitivities of single receptor cells in the lateral, median, and ventral eyes of normal and white-eyed Limulus. J. gen. Physiol. 55, 787–801 (1970).
—, Smith, T. G., Jr.: A hyperpolarizing component of the receptor potential in the median ocellus of Limulus. Science 162, 677–679 (1968).
Patten, W., Redenbaugh, W. A.: Studies of Limulus polyphemus. II. J. Morph. 16, 91–200 (1900).
Potter, D. D., Furshpan, E. J., Lennox, E. S.: Connections between cells of the developing squid as revealed by electrophysiological methods. Proc. nat. Acad. Sci. (Wash.) 55, 328–335 (1966).
Stretton, A. O. W., Kravitz, E. A.: Neuronal geometry: determination with a technique of intracellular dye injection. Science 162, 132–134 (1968).
Waterman, T. H.: Action potentials from an arthropod ocellus: the median ocellus of Limulus. Proc. nat. Acad. Sci. (Wash.) 39, 687–694 (1953).
Author information
Authors and Affiliations
Additional information
Supported in part by NIH EY00312 and EY00377.
We would like to thank Dr. W. K. Stell, Dr. A. C. Bell, and Dr. W. H. Fahrenbach for their helpful discussions.
Rights and permissions
About this article
Cite this article
Jones, C., Nolte, J. & Brown, J.E. The anatomy of the median ocellus of Limulus . Z. Zellforsch. 118, 297–309 (1971). https://doi.org/10.1007/BF00331188
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00331188