DOI: 10.5061/dryad.tmpg4f59t
title: Cheating death: Selection on digestive physiology overcomes expected growth costs of anti-predator defenses

description: Organisms often face a fundamental trade-off between growth and predator
 avoidance, especially when traits that enhance growth also increase
 predation risk. While many species reduce activity in response to
 predators, potentially constraining growth, this trade-off can be
 mitigated if alternative traits, such as digestive efficiency, compensate
 for reduced activity, enabling organisms to minimize growth costs while
 evading predators. To test this idea, we combined a mesocosm experiment
 with lab-based digestive physiological assays to examine survival
 selection and plasticity in damselfly larvae exposed to fish predators. We
 found that selection favored less active individuals, yet this reduction
 in activity did not suppress growth. Instead, plastic increases in
 consumption rate, selection for greater assimilation efficiency, and
 selection for weaker plastic digestive stress responses allowed
 individuals to maintain growth despite reduced activity and elevated
 metabolic rates. We provide here two datasets related to this study. The
 first, titled Mass.Data, contains the data used to determine the ratio of
 damselfly wet to dry mass that was necessary for calculating relative
 growth rate and other measures of digestive physiology in the experiment.
 The second dataset, Assimilation.Data, contains the data for activity
 rates, digestive physiology, and all other associated experimental
 measurements for comparing selective and plastic responses to predator
 presence in damselflies.
description: # Cheating death: Selection on digestive physiology overcomes expected
 growth costs of anti-predator defenses Dataset DOI:
 [10.5061/dryad.tmpg4f59t](10.5061/dryad.tmpg4f59t) ## Description of the
 data and file structure ### Files and variables #### File:
 Assimilation.Data.csv **Description:** This is the main data set
 containing the data for activity rates and digestive physiology measures.
 NAs, specifically in the Daphnia_bodies columns, are not applicable, as
 there were no bodies left over (all consumed). ##### Variables *
 Tank: Designation of the larger mesocosm tank * Cage: Designation of the
 smaller enclosure tank within each mesocosm * Individual: An individual
 identifier * Previous_treatment: Whether a free or caged predator was
 present * \#_of_gills: # of gill present * treatment: Predator cue
 treatment (1 = without cue, 2 = with cue) *
 Damselfly_Tube_Weight: Microcentrifuge mass/mg * Damselfly_Weight_Initial:
 Initial mass/mg * exuviae_weight_initial: Exuvia mass/mg if present *
 Damselfly_Weight_Final: Final mass/mg * exuviae_weight_final: Final exuvia
 mass/mg if present * Daphnia_1_Eaten: #Eaten during first feeding *
 Daphnia_1_Uneaten: #Not eaten during first feeding * Daphnia_bodies_1:
 Daphnia not alive (found dead) during round 1 * Daphnia_1_weight: Mass of
 first feeding/mg * Daphnia_2_Eaten: #Eaten during second feeding *
 Daphnia_2_Uneaten: #Not eaten during second feeding *
 Daphnia_bodies_2: Daphnia not alive (found dead) during round 2 *
 Daphnia_2_weight: Mass at second feeding/mg * Daphnia_3_Eaten: #Eaten
 during third feeding * Daphnia_3_Uneaten: #Not eaten during third feeding
 * Daphnia_bodies_3: Daphnia not alive (found dead) during round 3 *
 Daphnia_3_weight: Mass at third feeding/mg * Daphnia_4_Eaten: #Eaten
 during fourth feeding * Daphnia_4_Uneaten: #Not eaten during fourth
 feeding * Daphnia_bodies_4: Daphnia not alive (found dead) during round 4
 * Daphnia_4_weight: Mass at fourth feeding/mg *
 Feces_tube_weight: Microcentrifuge tube mass/mg for feces *
 Tube_with_feces: Microcentrifuge tube mass for feces with feces/mg *
 activity(mm): Activity rate - mm in 3 hrs * headwidth(mm): Head width in
 mm #### File: Mass.Data.csv **Description:** This data set contains the
 data to determine the ratio of wet mass to dry mass. Individual are
 numbered individual damselflies, Vial_Mass is the mass of the centrifuge
 tube used to house the individual during drying, and Wet_Mass and
 Dry_Mass, are the mass of the individuals + the tube mass before and after
 drying in the oven, respectively. ##### Variables * Individual: Individual
 damselfly * Vial_Mass: Mass of empty vial/mg * Wet_Mass: Mass of vial +
 damselfly/mg * Dry_Mass: Mass of vial + damselfly/mg after having been
 dried for 24hr