Colour vision of green turtle (Chelonia mydas) hatchlings: Do they still prefer blue under water?
- Published
- Accepted
- Subject Areas
- Animal Behavior, Natural Resource Management
- Keywords
- marine turtle colour vision, species-specific management tools, innate behavioural attraction, colour vision management.
- Copyright
- © 2018 Hall et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2018. Colour vision of green turtle (Chelonia mydas) hatchlings: Do they still prefer blue under water? PeerJ Preprints 6:e26642v1 https://doi.org/10.7287/peerj.preprints.26642v1
Abstract
Background. Several anatomical studies have concluded that green turtles (Chelonia mydas) possess the necessary anatomy for colour vision. Behavioural experiments were conducted with newly emerged hatchlings, testing their attraction towards light sources of different colours on their journey into the ocean. It was concluded that they are attracted to shorter wavelengths compared to longer ones, suggesting a possible attraction towards blue. Methods. Forty-one green turtles at six months of age were tested for their colour discrimination capabilities during a three-choice experiment under water. Three colours were selected for experimentation: blue, yellow, and red. Four different saturations (25, 50, 75, and 100%) of each of these colours were created, in total 12 colours were tested. The colour stimuli was printed and laminated paper colour blocks with food attached to force an interaction. Turtles were individually placed into their housing tanks with three different colours in front of them, from the same level saturation. The colour of the colour plate first approached and bitten by the turtle was noted. Results. The colour of the plate significantly influenced the likelihood that one food plate was selected more than another. Overall blue was selected 66.1%, yellow 18.2% and red 15.7%. There was also a significant interaction between the colour plate selected and the colour of the housing tank. Discussion.The findings of this study are consistent with previous research, concluding that green turtles are attracted to shorter wavelength colours, blue, compared to longer wavelength colours such as yellow or red. As the colour saturation changed and the colours became darker, turtles still chose food from the blue plates compared to the other options. These results indicate an attraction towards the colour blue, and as these research animals have never been in the wild, it is suggested that this attraction be an innate behavioural characteristic for green turtles.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Three green turtle hatchlings and their colour selections
Raw data information
The raw data for the experiment commented on in detail. Trial one (100%), trial two (50%), trial three (25%), and trial four (75%).