Signal reception and production form the basis of animal communication, and are largely constrained by environmental biophysical factors such as environmental light. However, the role of environmental light in producing variation in either signal reception or production has not been fully investigated. Using two distinct environmental light treatments, as well as a third treatment for a sampling of adults, I recorded corneal electroretinograms, lens transmission, and spectral reflectance of the body pattern of juvenile and adult Nile tilapia to chart the effect of environmental light on visual sensitivity and body colouration throughout ontogeny. Environmental light had an age-dependent effect on spectral sensitivity and an age-independent effect on spectral
reflectance. Spectral sensitivity in juveniles reared under a broad-spectrum light treatment and a red-shifted light treatment differed mostly at short wavelengths, where the irradiance of the two environmental light treatments differed the most. In contrast, adults reared under the two environmental light treatments did not differ in spectral sensitivity. Lens transmission did not differ significantly between environmental light treatments, indicating that differences in spectral sensitivity of juveniles originated in the
retina. Both juveniles and adults reared under the two environmental light treatments
differed in spectral reflectance, and adults transferred to the third environmental light
treatment differed in spectral reflectance from their counterparts reared under the two
original treatments. These results demonstrate that environmental light plays a large role in shaping signal reception in juveniles and signal production throughout ontogeny, suggesting that environmental light has the capacity to drive ecological speciation. / Thesis (Master, Biology) -- Queen's University, 2012-12-03 11:32:59.441
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/7682 |
| Date | 06 December 2012 |
| Creators | Hornsby, Mark |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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