Hostname: page-component-84b7d79bbc-g5fl4 Total loading time: 0 Render date: 2024-07-25T15:06:31.155Z Has data issue: false hasContentIssue false
  • English
  • Français

Migration of chorioidal tapetal pigment in the spur dog Squaluls acanthias

Published online by Cambridge University Press:  11 May 2009

J. A. C. Nicol
J. A. C. Nicol
Affiliation:
The Plymouth Laboratory
Get access Rights & Permissions [Opens in a new window]

Extract

This research has been concerned with the movement of pigment in the occlusible tapetum lucidum of the spur dog Squalus acanthias. The pigment expands and covers the reflecting plates of the tapetum in light, and retreats and uncovers the plates in darkness. Movement of pigment in one eye occurs independently of that in the other. Normal movement of pigment is not affected by cutting the optic nerves and oculomotor nerves, by sectioning the cord immediately behind the medulla, nor by excising the pituitary and pineal glands. It is concluded that the process is not under nervous or hormonal control. It occurs normally in excised opened eyes that are kept in oxygenated Ringer solution, but not under partial or fully anoxic conditions. The pigment cells of the chorioid seem to be behaving as independent effectors, sensitive to light. The pigment expands in tapeta freed of retina, in light or darkness. No explanation is yet available for the latter anomalous result. Measurements were made of the reflectivity of isolated tapeta, and curves are presented showing the progressive decrease of reflectivity accompanying expansion of pigment, and changes in the colour composition of the reflected light.

Type
Research Article
Information
Journal of the Marine Biological Association of the United Kingdom , Volume 45 , Issue 2 , June 1965 , pp. 405 - 427
Copyright
Copyright © Marine Biological Association of the United Kingdom 1965

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCE

Denton, E. J. & Nicol, J. A. C., 1964. The chorioidal tapeta of some cartilaginous fishes (Chondrichthyes). J. mar. biol. Ass. U.K., Vol. 44, pp. 219–58.CrossRefGoogle Scholar
Franz, V., 1905. Zur Anatomie, Histologie und funktionellen Gestaltung des Selachierauges. Jena. Z. Naturw., Bd. 40, pp. 697–840.Google Scholar
Franz, V., 1913. Sehorgan (Choroidea, Selachier). In Lehrbuch vergl. mikr. Anat. Wirbeltiere, ed. by Oppel, A., Teil 7, pp. 166–9. Jena: Fischer.Google Scholar
Nicholls, J. V. V., 1933. The effect of temperature variations and of certain drugs upon the gastric motility of elasmobranch fishes. Contr. Canad. Biol. Vol. 7, pp. 447–63.Google Scholar
Nicol, J. A. C., 1952. Autonomic nervous systems in lower chordates. Biol. rev., Vol. 27, pp. 1–49.CrossRefGoogle Scholar
Nicol, J. A. C., 1961. The tapetum in Scyliorhinus canicula. J. mar. biol. Ass. U.K., Vol. 41, pp. 271–7.CrossRefGoogle Scholar
Nicol, J. A. C., 1963. Some aspects of photoreception and vision in fishes. Adv. mar. Biol., Vol. 1, pp. 171–208.CrossRefGoogle Scholar
Nicol, J. A. C., 1964. Reflectivity of the chorioidal tapeta of selachians. J. Fish. Res. Bd. Can. Vol. 21, pp. 1089–1100.CrossRefGoogle Scholar
Norris, H. W. & Hughes, S. P., 1920. The cranial, occipital, and anterior spinal nerves of the dogfish, Squalus acanthias. J. comp. Neurol., Vol. 31, pp. 293–41.CrossRefGoogle Scholar
Parker, G. H., 1909. The integumentary nerves of fishes as photoreceptors and their significance for the origin of the vertebrate eyes. Am. J. Physiol., Vol. 25, pp. 77–80.CrossRefGoogle Scholar
Parker, G. H., 1948. Animal Colour Changes and their Neurohumours. Cambridge Univ. Press. 377 pp.Google Scholar
Pickford, G. E. & Atz, J. W., 1957. The Physiology of the Pituitary Gland of Fishes. New York Zoological Society. 613 pp.Google Scholar
Young, J. Z., 1933 a. The autonomic nervous system of selachians. Q. J. microsc. Sci., Vol. 75, pp. 571–624.Google Scholar
Young, J. Z., 1933 b. Comparative studies on the physiology of the iris.—I. Selachians. Proc. roy. Soc. B, Vol. 112, pp. 228–41.Google Scholar