DOI: 10.5061/dryad.1g1jwsv1g
title: One of these things is not like the other: mixed predator cues result in lopsided phenotypic responses in a Neotropical tadpole

description: Many organisms have evolved to produce different phenotypes in response to
 environmental variation. Dendropsophus ebraccatus tadpoles develop
 opposing shifts in morphology and coloration when they are exposed to
 invertebrate vs vertebrate predators. Each of these alternate phenotypes
 is adaptive, conferring a survival advantage against the predator with
 which tadpoles were reared but imposing a survival cost with the
 mismatched predator. Here, we measured the phenotypic response of tadpoles
 to graded cues and mixed cues of both fish and dragonfly nymphs. Prey
 species like D. ebraccatus commonly co-occur with both of these types of
 predators, amongst many others as well. In our first experiment, tadpoles
 increased investment in defensive phenotypes in response to increasing
 concentrations of predator cues. Whereas morphology only differed in the
 strongest cue predator, tail spot coloration differed even at the lowest
 cue concentration. In our second experiment, tadpoles reared with cues
 from both predators developed an intermediate yet skewed phenotype that
 was most similar to the fish-induced phenotype. Fish are more lethal than
 dragonfly larvae and thus tadpoles responded most strongly to the more
 dangerous predator, even though cues of each predator were evenly mixed.
 We demonstrate that not only do tadpoles assess predation risk via the
 concentration of predation cues in the water, but they also produce a
 stronger response to a more lethal predator even when the strength of cues
 is identical.
description: The data are collected from digital photographs taken of
 anesthetized animals. 14 landmarks are placed around the tadpole to
 quantify its shape using the StereoMorph package in R. Tail spot
 coloration is measured using ImageJ.
description: The data file contains two tps files, which can be analyzed by
 any software for Geometric Morphometrics. We used the
 <em>geomorph</em> package in R. .tps files can also be viewed
 with a standard text editor. 
description: # One of these things is not like the other: mixed and graded predator
 cues result in lopsided phenotypic responses in treefrog tadpoles Authors:
 Rosenthal, D.M., Deng, L., Rose, T., and Touchon, J.C. ### **DATA FILES**
 File name: **Expt1_tadpole_landmarks.tps** Description: A TPS file that
 contains the raw data of 14 landmarks collected for all tadpoles in
 Experiment 1 using the digitizing app in the StereoMorph R package. File
 name: **Expt2_tadpole_landmarks.tps** Description: A TPS file that
 contains the raw data of 14 landmarks collected for all tadpoles in
 Experiment 2 using the digitizing app in the StereoMorph R package. File
 name: **Expt1_color_measurements.csv** Description: Measurements of tail
 spot color and size of Dendropsophus ebraccatus tadpoles raised in low,
 medium or high concentrations of insect or fish chemical cues or as
 predator free controls. Also included are principal component scores from
 geometric morphometric analysis. Brightness: The average brightness of the
 tail spot. Values range from 0-255. Lower values indiciate darker colors
 and increasing values indicate brighter colors. Calculated from the
 Hue/Saturation/Brightness function in ImageJ. Hue: The average hue of the
 tail spot. Values range from 0-255. Lower values indiciate longer
 wavelength colors (e.g. red) and increasing values indicate colors with
 shorter\ wavelengths. Calculated from the Hue/Saturation/Brightness
 function in ImageJ. Saturation: The average saturation of the tail spot.
 Values range from 0-255. Lower values indiciate less pure colors and
 increasing values indicate colors with greater purity. Calculated from the
 Hue/Saturation/Brightness function in ImageJ. TSA: The area of the
 pigmented spot at the posterior end of the tail, in mm2. The area was
 drawn by eye. ID: A unique ID for each tadpole that is the randomly
 assigned number of their photo and the location of the tadpole in the
 photo. Each photo contained up to 5 tadpoles. Tank: Unique ID for each
 tank tadpoles were raised in. Family: Original code for family.
 Corresponds solely to the order that adult frogs were bred. Predator:
 Predator of origin for cues used in the experiment. Either Fish or
 Dragonfly. RiskLevel: Denotes the strength of the cue treatment that
 tadpoles were raised with as a categorical variable. 4 options (low,
 medium, high or none). 10 tadpoles from each family were raised with each
 chemical cue for 10 days. RiskLevel_cont: Denotes the strength of the cue
 treatment that tadpoles were raised with as a continuous variable, in
 terms of the number of tadpoles eaten per day per L of water. Csize: The
 centroid size resulting from the Procrustes fit of landmark data collected
 for each tadpole. relTSA: The relative Tail Spot Area, calculated as the
 square root of tail spot area divided by the centroid size. PC1: The first
 principal component from a PCA of the landmark data from 14 landmarks
 aligned with a General Procrustes Analysis. PC2: The second principal
 component from a PCA of the landmark data from 14 landmarks aligned with a
 General Procrustes Analysis. File name: **Expt2_color_measurements.csv**
 Description: Measurements of tail spot color and size of Dendropsophus
 ebraccatus tadpoles raised in dragonfly nymph or fish chemical cues alone,
 in mixed fish/dragonfly cues or as predator free controls. Also included
 are principal component scores from geometric morphometric analysis. Ind:
 Unique number for each tadpole. Tad: Identifies which tadpole is which in
 each photo. ID: A unique ID for each tadpole that is the randomly assigned
 number of their photo and the location of the tadpole in the photo. Each
 photo contained up to 5 tadpoles. Tank: Unique ID for each tank tadpoles
 were raised in. Family: Original code for family. Corresponds solely to
 the order that adult frogs were bred. Treatment: Denotes the predator cue
 treatment tadpoles were reared with. 4 options. DD: Dragonfly nymph cues
 only. FF: Fish cues only. DF: Mixed dragonfly nymph and fish cues. CC:
 Predator-free control. Brightness: The average brightness of the tail
 spot. Values range from 0-255. Lower values indiciate darker colors and
 increasing values indicate brighter colors. Calculated from the
 Hue/Saturation/Brightness function in ImageJ. Hue: The average hue of the
 tail spot. Values range from 0-255. Lower values indiciate longer
 wavelength colors (e.g. red) and increasing values indicate colors with
 shorter wavelengths. Calculated from the Hue/Saturation/Brightness
 function in ImageJ. Saturation: The average saturation of the tail spot.
 Values range from 0-255. Lower values indiciate less pure colors and
 increasing values indicate colors with greater purity. Calculated from the
 Hue/Saturation/Brightness function in ImageJ. TSA: The area of the
 pigmented spot at the posterior end of the tail, in mm2. The area was
 drawn by eye. Csize: The centroid size resulting from the Procrustes fit
 of landmark data collected for each tadpole. relTSA: The relative Tail
 Spot Area, calculated as the square root of tail spot area divided by the
 centroid size. PC1: The first principal component from a PCA of the
 landmark data from 14 landmarks aligned with a General Procrustes
 Analysis. PC2: The second principal component from a PCA of the landmark
 data from 14 landmarks aligned with a General Procrustes Analysis.