Polarisation vision in the dark : Green-sensitive photoreceptors in the nocturnal ball-rolling dung beetle Escarabaeus satyrus
(2024) In Journal of Experimental Biology 227(4).- Abstract
Many insects utilise the polarisation pattern of the sky to adjust their travelling directions. The extraction of directional information from this sky-wide cue is mediated by specialised photoreceptors located in the dorsal rim area (DRA). While this part of the eye is known to be sensitive to the ultraviolet, blue or green component of skylight, the latter has only been observed in insects active in dim light. To address the functional significance of green polarisation sensitivity, we define the spectral and morphological adaptations of the DRA in a nocturnal ball-rolling dung beetle–the only family of insects demonstrated to orient to the dim polarisation pattern in the night sky. Intracellular recordings revealed... (More)
Many insects utilise the polarisation pattern of the sky to adjust their travelling directions. The extraction of directional information from this sky-wide cue is mediated by specialised photoreceptors located in the dorsal rim area (DRA). While this part of the eye is known to be sensitive to the ultraviolet, blue or green component of skylight, the latter has only been observed in insects active in dim light. To address the functional significance of green polarisation sensitivity, we define the spectral and morphological adaptations of the DRA in a nocturnal ball-rolling dung beetle–the only family of insects demonstrated to orient to the dim polarisation pattern in the night sky. Intracellular recordings revealed polarisation-sensitive green photoreceptors in the DRA of Escarabaeus satyrus. Behavioural experiments verified the navigational relevance of this finding. To quantify the adaptive value of green sensitivity for celestial orientation at night, we also obtained the polarisation properties of the night sky in the natural habitat of the beetle. Calculations of relative photon catch revealed that under a moonlit sky the green-sensitive DRA photoreceptors can be expected to catch an order of magnitude more photons compared with the UV-sensitive photoreceptors in the main retina. The green-sensitive photoreceptors – which also show a range of morphological adaptations for enhanced sensitivity – provide E. satyrus with a highly sensitive system for the extraction of directional information from the night sky.
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- author
- Yilmaz, Ayse LU ; Belušič, Gregor ; Foster, James J. LU ; Tocco, Claudia LU ; Khaldy, Lana LU and Dacke, Marie LU
- organization
- publishing date
- 2024
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Dorsal rim area, Dung beetle, Green-sensitive, Nocturnal, Orientation, Polarised light
- in
- Journal of Experimental Biology
- volume
- 227
- issue
- 4
- article number
- jeb246374
- publisher
- The Company of Biologists Ltd
- external identifiers
-
- scopus:85186264608
- pmid:38284763
- ISSN
- 0022-0949
- DOI
- 10.1242/jeb.246374
- language
- English
- LU publication?
- yes
- id
- 4ff51de3-f707-43be-83e1-1f56de4fb21e
- date added to LUP
- 2024-03-26 12:27:28
- date last changed
- 2024-07-31 01:46:00
@article{4ff51de3-f707-43be-83e1-1f56de4fb21e, abstract = {{<p>Many insects utilise the polarisation pattern of the sky to adjust their travelling directions. The extraction of directional information from this sky-wide cue is mediated by specialised photoreceptors located in the dorsal rim area (DRA). While this part of the eye is known to be sensitive to the ultraviolet, blue or green component of skylight, the latter has only been observed in insects active in dim light. To address the functional significance of green polarisation sensitivity, we define the spectral and morphological adaptations of the DRA in a nocturnal ball-rolling dung beetle–the only family of insects demonstrated to orient to the dim polarisation pattern in the night sky. Intracellular recordings revealed polarisation-sensitive green photoreceptors in the DRA of Escarabaeus satyrus. Behavioural experiments verified the navigational relevance of this finding. To quantify the adaptive value of green sensitivity for celestial orientation at night, we also obtained the polarisation properties of the night sky in the natural habitat of the beetle. Calculations of relative photon catch revealed that under a moonlit sky the green-sensitive DRA photoreceptors can be expected to catch an order of magnitude more photons compared with the UV-sensitive photoreceptors in the main retina. The green-sensitive photoreceptors – which also show a range of morphological adaptations for enhanced sensitivity – provide E. satyrus with a highly sensitive system for the extraction of directional information from the night sky.</p>}}, author = {{Yilmaz, Ayse and Belušič, Gregor and Foster, James J. and Tocco, Claudia and Khaldy, Lana and Dacke, Marie}}, issn = {{0022-0949}}, keywords = {{Dorsal rim area; Dung beetle; Green-sensitive; Nocturnal; Orientation; Polarised light}}, language = {{eng}}, number = {{4}}, publisher = {{The Company of Biologists Ltd}}, series = {{Journal of Experimental Biology}}, title = {{Polarisation vision in the dark : Green-sensitive photoreceptors in the nocturnal ball-rolling dung beetle Escarabaeus satyrus}}, url = {{http://dx.doi.org/10.1242/jeb.246374}}, doi = {{10.1242/jeb.246374}}, volume = {{227}}, year = {{2024}}, }