Run and hide: visual performance in a brittle star
Spatial vision was recently reported in a brittle star, Ophiomastix wendtii, which lacks discrete eyes, but little is known about its visual ecology. Our aim was to better characterize the vision and visual ecology of this unusual visual system. We tested animals’ orientation relative to vertical ba...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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Company of Biologists
2021
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| _version_ | 1826290012410347520 |
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| author | Sumner-Rooney, L Kirwan, J Lüter, C Ullrich-Lüter, E |
| author_facet | Sumner-Rooney, L Kirwan, J Lüter, C Ullrich-Lüter, E |
| author_sort | Sumner-Rooney, L |
| collection | OXFORD |
| description | Spatial vision was recently reported in a brittle star, Ophiomastix wendtii, which lacks discrete eyes, but little is known about its visual ecology. Our aim was to better characterize the vision and visual ecology of this unusual visual system. We tested animals’ orientation relative to vertical bar stimuli at a range of angular widths and contrast, to identify limits of angular and contrast detection. We also presented dynamic shadow stimuli, either looming towards or passing overhead the animal, to test for potential defensive responses. Finally, we presented animals lacking a single arm with a vertical bar stimulus known to elicit a response in intact animals. We found that O. wendtii orients to large (≥50°), high-contrast vertical bar stimuli, consistent with a shelter-seeking role and with photoreceptor acceptance angles estimated from morphology. We calculate poor optical sensitivity for individual photoreceptors, and predict dramatic oversampling for photoreceptor arrays. We also report responses to dark stimuli moving against a bright background - this is the first report of responses to moving stimuli in brittle stars and suggests additional defensive uses for vision in echinoderms. Finally, we found that animals missing a single arm orient worse to static stimuli, which requires further investigation. |
| first_indexed | 2024-03-07T02:37:40Z |
| format | Journal article |
| id | oxford-uuid:a95650c5-4e04-4e6d-a697-b2fb4d6c7da4 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:37:40Z |
| publishDate | 2021 |
| publisher | Company of Biologists |
| record_format | dspace |
| spelling | oxford-uuid:a95650c5-4e04-4e6d-a697-b2fb4d6c7da42022-03-27T03:07:50ZRun and hide: visual performance in a brittle starJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:a95650c5-4e04-4e6d-a697-b2fb4d6c7da4EnglishSymplectic ElementsCompany of Biologists2021Sumner-Rooney, LKirwan, JLüter, CUllrich-Lüter, ESpatial vision was recently reported in a brittle star, Ophiomastix wendtii, which lacks discrete eyes, but little is known about its visual ecology. Our aim was to better characterize the vision and visual ecology of this unusual visual system. We tested animals’ orientation relative to vertical bar stimuli at a range of angular widths and contrast, to identify limits of angular and contrast detection. We also presented dynamic shadow stimuli, either looming towards or passing overhead the animal, to test for potential defensive responses. Finally, we presented animals lacking a single arm with a vertical bar stimulus known to elicit a response in intact animals. We found that O. wendtii orients to large (≥50°), high-contrast vertical bar stimuli, consistent with a shelter-seeking role and with photoreceptor acceptance angles estimated from morphology. We calculate poor optical sensitivity for individual photoreceptors, and predict dramatic oversampling for photoreceptor arrays. We also report responses to dark stimuli moving against a bright background - this is the first report of responses to moving stimuli in brittle stars and suggests additional defensive uses for vision in echinoderms. Finally, we found that animals missing a single arm orient worse to static stimuli, which requires further investigation. |
| spellingShingle | Sumner-Rooney, L Kirwan, J Lüter, C Ullrich-Lüter, E Run and hide: visual performance in a brittle star |
| title | Run and hide: visual performance in a brittle star |
| title_full | Run and hide: visual performance in a brittle star |
| title_fullStr | Run and hide: visual performance in a brittle star |
| title_full_unstemmed | Run and hide: visual performance in a brittle star |
| title_short | Run and hide: visual performance in a brittle star |
| title_sort | run and hide visual performance in a brittle star |
| work_keys_str_mv | AT sumnerrooneyl runandhidevisualperformanceinabrittlestar AT kirwanj runandhidevisualperformanceinabrittlestar AT luterc runandhidevisualperformanceinabrittlestar AT ullrichlutere runandhidevisualperformanceinabrittlestar |