DOI: 10.5061/dryad.0jm1dt2
title: Data from: 18S rRNA metabarcoding diet analysis of the predatory fish community across seasonal changes in prey availability

description: Predator-prey relationships are important ecological interactions,
 affecting biotic community composition and energy flow through a system,
 and are of interest to ecologists and managers. Morphological diet
 analysis has been the primary method used to quantify the diets of
 predators, but emerging molecular techniques using genetic data can
 provide more accurate estimates of relative diet composition. This study
 used sequences from the 18S V9 rRNA barcoding region to identify prey
 items in the gastrointestinal (GI) tracts of predatory fishes. Predator GI
 samples were taken from the Black River, Cheboygan Co., MI, USA (n=367
 samples, 12 predator species) during periods of high prey availability,
 including the larval stage of regionally threatened lake sturgeon
 (Acipenser fulvescens Rafinesque 1817) in late May/early June of 2015 and
 of relatively lower prey availability in early July of 2015. DNA was
 extracted and sequenced from 355 samples (96.7%), and prey DNA was
 identified in 286 of the 355 samples (80.6%). Prey were grouped into 33
 ecologically significant taxonomic groups based on the lowest taxonomic
 level sequences that could be identified using sequences available on
 GenBank. Changes in the makeup of diet composition, dietary overlap, and
 predator preference were analyzed comparing the periods of high and low
 prey abundance. Some predator species exhibited compositional changes in
 diet. Dietary overlap was slightly but significantly higher during the
 period of high prey abundance. There was little evidence for large changes
 in predator preference between the two periods. This study demonstrates
 the utility of molecular diet analysis in understanding predator-prey
 interactions in complex freshwater communities.
description: README_Waraniak_18S_MetabarcodingREADME file describing the contents of the other data files and R script in this Dryad package.Waraniak_18S_AnalysesR code used to perform most of the analyses and produce Figures 4, 5, and 6 in the associated manuscript.Waraniak_18S_dietseqs_cleanedFASTA file output from mothur with information on the number of reads, nucleotide sequence, and diet samples associated with each of the operational taxonomic units (OTUs) created by the mothur analysis.Waraniak_18S_ESU_BiomassData file including information on the biomass of prey items for each night of the drift net survey used to estimate prey availability. Necessary input file for some analyses in the R code.Waraniak_18S_OTUseq_countsData file with information on the read count for each of the OTUs from the mothur analysis in each of the predator diet samples. Also contains information on the taxonomic group assigned to each OTU based on the NCBI blast protocol outlined in the manuscript.Waraniak_18S_Preyseq_PropsData file that contains the proportions of read counts from the different prey ESUs found in the predator diet samples. Also contains data for the environmental variables associated with each diet sample. Necessary input file for the analyses in the R code.