DOI: 10.5061/dryad.n5tb2rc5t
title: Dynamic color change in the grouper Variola louti during interspecific interactions and swimming

description: Animals can change their body color for various ecological functions. In
 fish, rapid dynamic color change is primarily known in contexts of
 intraspecific communication and camouflage, while examples in
 interspecific contexts are rare. We studied dynamic color changes and
 their associated behaviors in the grouper Variola louti in its native
 coral reef environment in the Red Sea. Using underwater videos to record
 natural behaviors and color-calibrated still images to measure body
 colors, we quantified color displays as the brightness of the body and the
 contrast of three distinct patterns: body patches, head stripe, and side
 bars. V. louti exhibited a diverse range of pattern displays, which
 rapidly transformed according to its behavioral shifts. A high-contrast
 head stripe pattern was observed when V. louti engaged in agonistic
 interspecific interactions, but was interestingly absent when hunting
 alone or in cooperation with moray eels. The brightness of V. louti’s body
 color and the contrasts of the body patches and side bars were associated
 with its swimming behavior. Darker body colors and high contrast body
 patches and side bars were expressed when the fish rested on the bottom,
 whereas bright and uniform body colors were displayed when swimming higher
 above the reef. Our results suggest that V. louti utilizes dynamic color
 displays for camouflage and interspecific communication in agonistic and
 competitive interspecific interactions. These findings highlight the
 importance of dynamic color changes for communication and provide valuable
 insights into the behavioral ecology of animals.
description: # Dynamic color change in the grouper Variola louti during interspecific
 interactions and swimming Authors: Sagi Marom, Moshe Kiflawi, Derya
 Akkaynak, Roi Holzman Journal: Behavioral Ecology Article DOI:
 10.1093/beheco/araf005 Dryad Dataset
 DOI: [https://doi.org/10.5061/dryad.n5tb2rc5t](https://doi.org/10.5061/dryad.n5tb2rc5t) ## Description of the data and file structure The files related to this article in datadryad.org include: 1. MATLAB files with the code to perform image processing as explained in the article: * White balancing by RGB equalization. * Sampling areas from the images and extracting color values. 2. An Excel file with our dataset table and a readme sheet with explanations on every column. ### Files and variables #### File: MATLAB\_Code.zip **Description:** MATLAB files with the code to perform image processing as explained in the article: #### File: Dataset\_and\_readme.xlsx **Description:** An Excel file with our dataset table and a readme sheet with explanations on every column. If the location of a pattern was obstructed in an image, the value was set to NA. Consequently, all cells related to the NA variable in the sample will be NA as well. ##### Variables | Sample\_ID | serial number of the sample | | :------------- | :-------------------------------------------------------------------------------------------------------------------------------------------------- | | Date | date of image capture | | Time | time of image capture | | SideBars\_R | average Red value for the Side Bars pattern | | SideBars\_G | average Green value for the Side Bars pattern | | SideBars\_B | average Blue value for the Side Bars pattern | | SideBars | average RGB (columns D-F) value for the Side Bars pattern | | HeadStripe\_R | average Red value for the Head Stripe pattern | | HeadStripe\_G | average Green value for the Head Stripe pattern | | HeadStripe\_B | average Blue value for the Head Stripe pattern | | HeadStripe | average RGB (columns H-J) value for the Head Stripe pattern | | BodyPatches\_R | average Red value for the Body Patches pattern | | BodyPatches\_G | average Green value for the Body Patches pattern | | BodyPatches\_B | average Blue value for the Body Patches pattern | | BodyPatches | average RGB (columns L-N) value for the Body Patches pattern | | BodyColor\_R | average Red value for the Body Color | | BodyColor\_G | average Green value for the Body Color | | BodyColor\_B | average Blue value for the Body Color | | BodyColor | average RGB (columns P-R) value for the Body Color | | Position | Estimated distance of V. louti from the sea-floor (&lt;1m - close, &gt;=1m - far) | | Speed | Estimated swimming speed of V. louti | | Interaction | The species of the interacted organisms | | Activity | activity of V. louti | | Activity\_Type | The interaction type of the activity: Solitary / Agonistic / Cooperative | | Fish\_ID | Identification mark of the subject V. louti. If it did not have distict ID marks, it was named after the date and order it was spotted (DD-MM-abc). | | Image | image file name | | Chart | chart file name (corresponding to the image file) | | ImagePath | image file path | | ChartPath | chart file path | | AnalysisDate | date of analysis | | AnalysisTime | time of analysis | | ss1R | measurment of the average Red value inside the first (most anterior) side bar. Measured in units of 0-1. | | ss1G | measurment of the average Green value inside the first (most anterior) side bar. Measured in units of 0-1. | | ss1B | measurment of the average Blue value inside the first (most anterior) side bar. Measured in units of 0-1. | | ss1 | average of the RGB measurments inside the first (most anterior) side bar | | a1R | measurment of the average Red value between the first and second side bars. Measured in units of 0-1. | | a1G | measurment of the average Green value between the first and second side bars. Measured in units of 0-1. | | a1B | measurment of the average Blue value between the first and second side bars. Measured in units of 0-1. | | a1 | average of the RGB measurments between the first and second side bars | | ss2R | measurment of the average Red value inside the second (second most anterior) side bar. Measured in units of 0-1. | | ss2G | measurment of the average Green value inside the second (second most anterior) side bar. Measured in units of 0-1. | | ss2B | measurment of the average Blue value inside the second (second most anterior) side bar. Measured in units of 0-1. | | ss2 | average of the RGB measurments inside the second (second most anterior) side bar | | a2R | measurment of the average Red value between the second and third side bars. Measured in units of 0-1. | | a2G | measurment of the average Green value between the second and third side bars. Measured in units of 0-1. | | a2B | measurment of the average Blue value between the second and third side bars. Measured in units of 0-1. | | a2 | average of the RGB measurments between the second and third side bars | | hsR | measurment of the average Red value inside Head Stripe. Measured in units of 0-1. | | hsG | measurment of the average Green value inside the Head Stripe. Measured in units of 0-1. | | hsB | measurment of the average Blue value inside the Head Stripe. Measured in units of 0-1. | | hs | average of the RGB measurments inside the Head Stripe | | nhsR | measurment of the average Red value outside and adjacent to the Head Stripe. Measured in units of 0-1. | | nhsG | measurment of the average Green value outside and adjacent to the Head Stripe. Measured in units of 0-1. | | nhsB | measurment of the average Blue value outside and adjacent to the Head Stripe. Measured in units of 0-1. | | nhs | average of the RGB measurments outside and adjacent to the Head Stripe | | bp1R | measurment of the average Red value inside the most distinct Body Patch. Measured in units of 0-1. | | bp1G | measurment of the average Green value inside the most distinct Body Patch. Measured in units of 0-1. | | bp1B | measurment of the average Blue value inside the most distinct Body Patch. Measured in units of 0-1. | | bp1 | average of the RGB measurments inside the most distinct Body Patch | | nbp1R | measurment of the average Red value outside and adjacent to the most distinct Body Patch. Measured in units of 0-1. | | nbp1G | measurment of the average Green value outside and adjacent to the most distinct Body Patch. Measured in units of 0-1. | | nbp1B | measurment of the average Blue value outside and adjacent to the most distinct Body Patch. Measured in units of 0-1. | | nbp1 | average of the RGB measurments outside and adjacent to the most distinct Body Patch | | ss1\_rectout | XY coordinates of the sampled area of inside the first (most anterior) Side Bar | | a1\_rectout | XY coordinates of the sampled area of between the first and second Side Bars | | ss2\_rectout | XY coordinates of the sampled area of inside the second (second most anterior) Side Bar | | a2\_rectout | XY coordinates of the sampled area of between the socond and third Side Bars | | hs\_rectout | XY coordinates of the sampled area of inside the Head Stripe | | nhs\_rectout | XY coordinates of the sampled area of outside and adjacet to the Head Stripe | | bp1\_rectout | XY coordinates of the sampled area of inside the most distinct Body Patch | | nbp1\_rectout | XY coordinates of the sampled area of outside and adjacent to the most distinct Body Patch | | bc\_rectout | XY coordinates of the sampled area of the Body Color |