Cheating death: Selection on digestive physiology overcomes expected growth costs of anti-predator defenses
Data files
Dec 18, 2025 version files 51.76 KB
-
Assimilation.Data.csv
48.50 KB
-
Mass.Data.csv
494 B
-
README.md
2.77 KB
Abstract
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.
Dataset DOI: 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
