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The Chorioidal Tapeta of some Cartilaginous Fishes (Chondrichthyes)

  • E. J. Denton (a1) and J. A. C. Nicol (a1)

1. A study of the histology of the eyes of some cartilaginous fishes has been made with special reference to their reflecting tapeta.

2. The rate and way in which the pigment in the melanophores spreads over the reflecting cells of the tapetum of Squalus acanthias when it is lightadapted are described.

3. The reflecting plates in the tapeta are about parallel to the plane of the retina in the centre of the eye, but as we move towards the periphery they become more oblique, until near the ora they are almost perpendicular to the plane of the retina. It is shown that when we take account of the way in which the pupil limits the light which can reach the retina in all these situations the plates are arranged to be roughly perpendicular to the incident light. They reflect light either back through the pupil or on to the very black inside surface of the iris and do not scatter it to other parts of the eye.

4. The reflectivity of tapeta for various angles and various wave-lengths of light has been found by several different methods, and a new and simple way of measuring the reflectivity of natural tissues is described. For the blue and green lights which will be those reaching the eye in life the reflectivity is very high, over 80%, and so approaches that of a good metallic mirror.

5. The external segments of the retinal rods of cartilaginous fishes which have well-developed tapeta are only about half as long as those of other fish living in the same environment, and the retinal optical densities of photosensitive pigments in these fish are only about a half of those of fish without reflecting tapeta.

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H. B. Barlow , 1956. Purkinje shift and retinal noise. Nature, Lond., Vol. 179, pp. 255–6.

B. Berland , 1961. Copepod Ommatokoita elongata (Grant) in the eyes of the Greenland shark—a possible cause [case] of mutual dependence. Nature, Lond., Vol. 191, pp. 829–30.

E. J. Denton , 1956. The responses of the pupil of Gekko gekko to external light stimulus. J. gen. Physiol., Vol. 40, pp. 201–16.

E. J. Denton , 1959. The contributions of the orientated photosensitive and other molecules to the absorption of whole retina. Proc. Roy. Soc. B, Vol. 150, pp. 7894.

E. J. Denton & M. A. Walker , 1958. The visual pigment of the conger eel. Proc. Roy. Soc. B, Vol. 148, pp. 257–69.

E. J. Denton & J. H. Wyllie , 1955. Study of the photosensitive pigments in the pink and green rods of the frog. J. Physiol., Vol. 127, pp. 81–9.

J. E. Dowling , 1960. Chemistry of visual adaptation in the rat. Nature, Lond., Vol. 188, pp. 114–18.

J. E. Dowling & G. Wald , 1960. The biological function of vitamin A acid. Proc. nat. Acad. Sci., Wash., Vol. 46, pp. 587608.

P. W. Gilbert , 1962. The behavior of sharks. Sci. Amer., Vol. 207, No. 1, pp. 60–8.

R. Gunter , H. G. W. Harding & W. S. Stiles , 1951. Spectral reflexion factor of the cat's tapetum. Nature, Lond., Vol. 168, pp. 293–4.

D. M. Lewis , 1957. Regeneration of rhodopsin in the albino rat. J. Physiol., Vol. 136, pp. 624–31.

F. W. Munz , 1958. Photosensitive pigments from the retinae of certain deep-sea fishes. J. Physiol., Vol. 140, pp. 220–35.

J. V. V. Nicholls , 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.

A. Pirie & D. M. Simpson , 1946. Preparation of a fluorescent substance from the eye of the dogfish (Squalus acanthias). Biochem. J., Vol. 40, pp. 1420.

W. A. H. Rushton , 1956. The rhodopsin density in the human rods. J. Physiol., Vol. 134, pp. 3046.

W. A. H. Rushton , 1961. Dark-adaptation and the regeneration of rhodopsin. J. Physiol., Vol. 156, pp. 166–78.

R. L. Sidman , 1957. The structure and concentration of solids in photoreceptor cells studied by refractometry and interference microscopy. J. biophys. biochem. Cytol., Vol. 3, pp. 1530.

G. Wald , 1955. The photoreceptor process in vision. Amer. J. Ophthal., Vol. 40, pp. 1841.

G. Wald , P. K. Brown & P. S. Brown , 1957. Visual pigments and depths of habitat of marine fishes. Nature, Lond., Vol. 180, pp. 969–71.

G. Wald , P. K. Brown & D. Kennedy , 1957. The visual system of the alligator. J. gen. Physiol., Vol. 40, pp. 703–13.

R. A. Weale , 1953. The spectral reflectivity of the cat's tapetum measured in situ. J. Physiol., Vol. 119, pp. 3042.

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Journal of the Marine Biological Association of the United Kingdom
  • ISSN: 0025-3154
  • EISSN: 1469-7769
  • URL: /core/journals/journal-of-the-marine-biological-association-of-the-united-kingdom
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