The harp seal, Pagophilus groenlandicus (Erxleben, 1777). VI. Structure of retina
The retina of the harp seal (Pagophilus groenlandicus) was studied by means of the light microscope. Ganglion cells occupy a single layer. Thinly dispersed throughout this layer are giant ganglion cells. There is no area centralis. The inner nuclear layer consists of large horizontal cell processes...
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Language: | English |
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Canadian Science Publishing
1970
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Online Access: | http://dx.doi.org/10.1139/z70-058 http://www.nrcresearchpress.com/doi/pdf/10.1139/z70-058 |
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crcansciencepubl:10.1139/z70-058 2024-09-15T18:10:47+00:00 The harp seal, Pagophilus groenlandicus (Erxleben, 1777). VI. Structure of retina Nagy, A. R. Ronald, K. 1970 http://dx.doi.org/10.1139/z70-058 http://www.nrcresearchpress.com/doi/pdf/10.1139/z70-058 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Zoology volume 48, issue 2, page 367-370 ISSN 0008-4301 1480-3283 journal-article 1970 crcansciencepubl https://doi.org/10.1139/z70-058 2024-08-01T04:10:01Z The retina of the harp seal (Pagophilus groenlandicus) was studied by means of the light microscope. Ganglion cells occupy a single layer. Thinly dispersed throughout this layer are giant ganglion cells. There is no area centralis. The inner nuclear layer consists of large horizontal cell processes with bipolar and amacrine cells between the horizontal cell processes. The outer nuclear layer is the thickest of all retinal layers. Its density is constant in the central and peripheral areas of the retina, similar to that found in the inner nuclear and ganglion layers. Only rod photoreceptors were found; therefore it is presumed that seals have no color vision. The tapetum covers an extensive area and is 32–34 cellular layers thick centrally, diminishing in thickness peripherally. The combination of tapetum and rod receptors makes possible excellent visual sensitivity to dim light. Article in Journal/Newspaper Harp Seal Pagophilus groenlandicus Canadian Science Publishing Canadian Journal of Zoology 48 2 367 370 |
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Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
description |
The retina of the harp seal (Pagophilus groenlandicus) was studied by means of the light microscope. Ganglion cells occupy a single layer. Thinly dispersed throughout this layer are giant ganglion cells. There is no area centralis. The inner nuclear layer consists of large horizontal cell processes with bipolar and amacrine cells between the horizontal cell processes. The outer nuclear layer is the thickest of all retinal layers. Its density is constant in the central and peripheral areas of the retina, similar to that found in the inner nuclear and ganglion layers. Only rod photoreceptors were found; therefore it is presumed that seals have no color vision. The tapetum covers an extensive area and is 32–34 cellular layers thick centrally, diminishing in thickness peripherally. The combination of tapetum and rod receptors makes possible excellent visual sensitivity to dim light. |
format |
Article in Journal/Newspaper |
author |
Nagy, A. R. Ronald, K. |
spellingShingle |
Nagy, A. R. Ronald, K. The harp seal, Pagophilus groenlandicus (Erxleben, 1777). VI. Structure of retina |
author_facet |
Nagy, A. R. Ronald, K. |
author_sort |
Nagy, A. R. |
title |
The harp seal, Pagophilus groenlandicus (Erxleben, 1777). VI. Structure of retina |
title_short |
The harp seal, Pagophilus groenlandicus (Erxleben, 1777). VI. Structure of retina |
title_full |
The harp seal, Pagophilus groenlandicus (Erxleben, 1777). VI. Structure of retina |
title_fullStr |
The harp seal, Pagophilus groenlandicus (Erxleben, 1777). VI. Structure of retina |
title_full_unstemmed |
The harp seal, Pagophilus groenlandicus (Erxleben, 1777). VI. Structure of retina |
title_sort |
harp seal, pagophilus groenlandicus (erxleben, 1777). vi. structure of retina |
publisher |
Canadian Science Publishing |
publishDate |
1970 |
url |
http://dx.doi.org/10.1139/z70-058 http://www.nrcresearchpress.com/doi/pdf/10.1139/z70-058 |
genre |
Harp Seal Pagophilus groenlandicus |
genre_facet |
Harp Seal Pagophilus groenlandicus |
op_source |
Canadian Journal of Zoology volume 48, issue 2, page 367-370 ISSN 0008-4301 1480-3283 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/z70-058 |
container_title |
Canadian Journal of Zoology |
container_volume |
48 |
container_issue |
2 |
container_start_page |
367 |
op_container_end_page |
370 |
_version_ |
1810448356488511488 |