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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

A dune with a view: the eyes of a neotropical fossorial lizard

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Author(s):
Yovanovich, Carola A. M. [1] ; Pierotti, Michele E. R. [1, 2] ; Rodrigues, Miguel Trefaut [1] ; Grant, Taran [1]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Inst Biosci, Dept Zool, Sao Paulo - Brazil
[2] Smithsonian Trop Res Inst, Naos Marine Labs, Panama City - Panama
Total Affiliations: 2
Document type: Journal article
Source: Frontiers in Zoology; v. 16, JUN 10 2019.
Web of Science Citations: 0
Abstract

BackgroundLizards are excellent models to study the adaptations of the visual system to different scenarios, and surface-dwelling representatives have been relatively well studied. In contrast, very little is known about the functional anatomy of the eyes of fossorial lineages, and properties such as the light transmission by the ocular media have never been characterised in any fossorial species. Some lizards in the family Gymnophthalmidae endemic to the sand dunes of North Eastern Brazil have evolved sand-burrowing habits and nocturnal activity. Lizards in the sister group to Gymnophthalmidae, the family Teiidae, have decidedly diurnal and epigeal lifestyles, yet they are equally poorly known in terms of visual systems. We focussed on the eye anatomy, photoreceptor morphology and light transmittance properties of the ocular media and oil droplets in the gymnophthalmid Calyptommatus nicterus and the teiid Ameivula ocellifera.ResultsThe general organisation of the eyes of the fossorial nocturnal C. nicterus and the epigeal diurnal A. ocellifera is remarkably similar. The lenses are highly transmissive to light well into the ultraviolet part of the spectrum. The photoreceptors have the typical cone morphology, with narrow short outer segments and oil droplets. The main difference between the two species is that C. nicterus has only colourless oil droplets, whereas A. ocellifera has colourless as well as green-yellow and pale-orange droplets.ConclusionsOur results challenge the assumption that fossorial lizards undergo loss of visual function, a claim that is usually guided by the reduced size and external morphology of their eyes. In the case of C. nicterus, the visual system is well suited for vision in bright light and shows specialisations that improve sensitivity in dim light, suggesting that they might perform some visually-guided behaviour above the surface at the beginning or the end of their daily activity period, when light levels are relatively high in their open dunes habitat. This work highlights how studies on the functional anatomy of sensory systems can provide insights into the habits of secretive species. (AU)

FAPESP's process: 15/14857-6 - A systematic study of amphibian visual systems: from evolution of diel patterns to physiological limits for colour vision
Grantee:Carola Anabel Mariana Yovanovich
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 18/11502-0 - The hyperdiverse amphibian fauna of Brazil as a model system for comparative ecophysiology and genomics of vision
Grantee:Taran Grant
Support Opportunities: Research Grants - Visiting Researcher Grant - International
FAPESP's process: 11/50146-6 - Comparative phylogeography, phylogeny, paleoclimate modeling, and taxonomy of neotropical reptiles and amphibians
Grantee:Miguel Trefaut Urbano Rodrigues
Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
FAPESP's process: 12/10000-5 - A multi-disciplinary approach to the study of amphibian diversification
Grantee:Taran Grant
Support Opportunities: Research Grants - Young Investigators Grants