Cichlid visual system is highly adaptive to the environment. Fish visual abilities are deter- mined by composition of opsin-based photosensitive pigments located in photoreceptor cells (rods and cones) as well as their distribution. In this thesis, four species of Lake Barombi Mbo cichlids were targeted: Stomatepia mariae, Konia eisentrauti, Konia dikume and Myaka myaka. Shallow-water cichlids K. eisentrauti and S. mariae express these types of cone opsin genes: LWS, RH2A (RH2Aβ more than RH2Aα), SWS2A and SWS2B. Contra- rily, both seasonally deep-water M. myaka and deep-water K. dikume lack expression of SWS2B and LWS in their retinae, but they express SWS2A and RH2Aα more than RH2Aβ, which corresponds to modified light conditions in deep water - a dimmer habitat lacking marginal parts of the spectrum (i.e., ultraviolet and red wavelengths). The photoreceptor distribution of selected species was investigated by means of fluorescent in situ hybridi- zation (FISH) in order to understand the performance and evolution of their visual per- ception with emphasis on the effect of depth. Distinctively, cichlid cones are arranged in a retinal mosaic consisting of short-wavelength sensitive single cones, each surrounded by four long-wavelength sensitive double cones. In this thesis, the same arrangement is...
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:405226 |
| Date | January 2019 |
| Creators | Remišová, Kateřina |
| Contributors | Musilová, Zuzana, Němec, Pavel |
| Source Sets | Czech ETDs |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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