DOI: 10.5061/dryad.0vt4b8hbv
title: Data from: Snake oil in action: Geographic and seasonal variability in epidermal lipids shape evaporative water loss in snakes

description: Many reptiles inhabit deserts, where there is a benefit to minimizing
 evaporative water loss (EWL) due to the risks to water balance imposed by
 the extreme heat and dryness. We compared the EWL of desert versus
 Mediterranean snakes and the content and composition of their epidermal
 lipids, which form the primary barrier against evaporation. We
 obtained shed skins from two farm-grown species (a desert specialist
 viper, Echis coloratus, and its Mediterranean
 relative, Daboia palaestinae) and from 17 captive snake species
 of both Mediterranean and desert origins, kept under identical conditions.
 Total EWL was measured in live snakes using flow-through respirometry.
 Cutaneous EWL was approximated in vitro through the shed skin, and
 epidermal lipids were quantified following extraction in n-hexane and
 identified using ultraperformance liquid chromatography-mass spectrometry
 (UPLC-MS).
description: # Data from: Snake oil in action: Geographic and seasonal variability in
 epidermal lipids shape evaporative water loss in snakes Dataset DOI:
 [10.5061/dryad.0vt4b8hbv](https://doi.org/10.5061/dryad.0vt4b8hbv) ##
 Description of the data and file structure ### Files and variables Data
 for Dubiner et al. "Snake oil in action: geographic and seasonal
 variability in epidermal lipids shape evaporative water loss in
 snakes". Table_S1_snakes.xlsx: Results of lipid extraction. Variables
 are: source (zoo vs farm), biome and season of origin, and lipid content
 (% of dry mass) in snake skins. * Source (zoo vs farm), biome and season
 of origin, and lipid content (% of dry mass) in snake skins.
 Table_S2_snakes.xlsx: Results of respirometry and *in vitro* evaporation.
 Extraction. Variables are: biome and season of origin, evaporative water
 loss (EWL, in mg/minute for respirometry and mg/day/cm^2^ or *in vitro*
 evaporation), and skin resistance to EWL (in seconds per meter) in snake
 skins. * Biome and season of origin, evaporative water loss (EWL, in
 mg/minute for respirometry and mg/day/cm^2^ for *in vitro* evaporation),
 and skin resistance to EWL (in seconds per meter) in snake skins.
 Table_S3_snakes.xlsx and Table_S3_snakes.csv: Peak areas (in
 microvolt-seconds) for all compounds identified from snake skin *n*-hexane
 extracts using UPLC-MS for *Daboia palaestinae* and *Echis coloratus*.
 "Calc. MW" is the calculated molar weight. "m/z" is
 the mass-to-charge ratio. "RT" is the retention time.
 "t-test" is between species for the specific variable. For each
 sample, "double bonds" (in fatty acids) and "chain
 length" (in ceramides) refer to the weighted mean across all
 compounds. * Variables are the specific compounds for each individual
 (plus summary statistics per species). Peak areas are given (in
 microvolt-seconds) for all compounds identified from snake skin *n*-hexane
 extracts using UPLC-MS for *Daboia palaestinae* and *Echis coloratus* (as
 well as all unknown compounds, pooled). "Calc. MW" is the
 calculated molar weight. "m/z" is the mass-to-charge ratio.
 "RT" is the retention time. "t-test" is between
 species for the specific variable. For each sample, "double
 bonds" (in fatty acids) and "chain length" (in ceramides)
 refer to the weighted mean across all compounds. Note: A version of Table
 3 is also available in CSV format.