Data from: Visual modelling supports the potential for prey detection by means of diurnal active photolocation in a small cryptobenthic fish
Data files
Jun 05, 2019 version files 243.44 KB
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Average gammarid body reflectance.csv
7.22 KB
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Average gammarid body transmission.csv
6.80 KB
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Background reflectance Haliopteris filiciana.csv
3.89 KB
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Coaxial reflectance values categorical.csv
17.67 KB
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Downwelling and sidewelling illuminant for analyses.csv
23.71 KB
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Eye reflectance conversion values categorical.csv
14.70 KB
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Ocular media values.csv
5.09 KB
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Ocular spark conversion on continuous scale.csv
147.85 KB
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SA scores Gammarid as perceived by Td pupil.csv
403 B
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SA scores Os as perceived by Gammarid eye MATRIX.csv
16.11 KB
Abstract
Active sensing has been well documented in animals that use echolocation and electrolocation. Active photolocation, or active sensing using light, has received much less attention, and only in bioluminescent nocturnal species. However, evidence has suggested the diurnal triplefin Tripterygion delaisi uses controlled iris radiance, termed ocular sparks, for prey detection. While this form of diurnal active photolocation was behaviourally described, a study exploring the physical process would provide compelling support for this mechanism. In this paper, we investigate the conditions under which diurnal active photolocation could assist T. delaisi in detecting potential prey. In the field, we sampled gammarids (genus Cheirocratus) and characterized the spectral properties of their eyes, which possess strong directional reflectors. In the laboratory, we quantified ocular sparks size and their angle-dependent radiance. Combined with environmental light measurements and known properties of the visual system of T. delaisi, we modeled diurnal active photolocation under various scenarios. Our results corroborate that diurnal active photolocation should help T. delaisi detect gammarids at distances relevant to foraging, 4.5 cm under favourable conditions and up to 2.5 cm under average conditions. To determine the prevalence of diurnal active photolocation for micro-prey, we encourage further theoretical and empirical work.