Estimating required sample sizes for gut content metabarcoding studies of dietary diversity in spiders

Spiders are dominant predators in terrestrial ecosystems, regulating invertebrate biomass through predation. However, analysing predation patterns in the field is challenging, especially as spiders are extra-intestinal liquid feeders and often active at night. Gut content metabarcoding (GCM) provides a cost-effective method to study the prey composition of spiders. In this study, we determine the minimum sample size of spider specimens required to obtain representative estimates of local prey composition. Six common spider species were studied using GCM and we show that the number of analysed individuals per spider species influenced the saturation levels for prey at different taxonomic levels. To achieve 90% saturation at the prey species level, between 50 and over 150 individuals per spider species had to be analysed, which is challenging for ecological multi-site studies. Hence we argue for consideration of coarser taxonomic levels, such as family or order, which often provide suffic..., , , # Estimating required sample sizes for gut content metabarcoding studies of dietary diversity in spiders

[https://doi.org/10.5061/dryad.3xsj3txpz](https://doi.org/10.5061/dryad.3xsj3txpz)

Data set contents:

### **Metadata:** 

file: metadata.csv

description: contains metadata of the samples

**Variables**
sample_id : unique sample identifier, (naming scheme corresponding only to collector, not any other quality of the sample)

type: sample type (spider or negative control)

species: species of the spider sample;
NA = not applicable to controls, as they contain no spider sample

### Sequences:

file: saturation_sequences.zip

Description: This folder consists of 264 fastaq.gz for 132 samples of different spider species or control samples (2 files per sample, forward and reverse read each). The raw sequence data originates from Illumina sequencing in fastq format.

### Prey species table

file: preyspecies.csv

Description: presence/absence data of prey species in every sample 

### P...,