DOI: 10.5061/dryad.vq83bk40h
title: Fitness effects of symbiotic relationships among arthropod predators

description: Symbiotic relationships shape ecological communities and often involve
 more than two species. Yet few experimental studies examine the impact of
 symbioses involving three species, particularly any mediating role of
 third parties, and none involving symbioses of predators. We investigated
 experimentally the synergistic and antagonistic fitness effects of three
 symbiotic spider predators across a broad latitudinal range and involving
 different species combinations. The three-dimensional web-complex
 of Cyrtophora spiders is a habitat patch to different associates
 – species of Argyrodes and web-building Leucauge spider guests. Our field
 experiments, which manipulated the presence of each guest species and
 determined the subsequent host weight change, revealed a remarkable
 consistency in fitness outcomes across the three populations, with the
 consequences of the interactions between two species depending upon the
 services provided by a third. Cyrtophora hosts intercepted more prey when
 web-building Leucauge guests were present and thus gained more weight. In
 contrast, Argyrodes guests exerted a fitness cost on their Cyrtophora
 host, but only when Leucauge guests were absent. A comparison of the prey
 consumed by Cyrtophora hosts and Argyrodes guests revealed that their
 diets (reflected in the size of prey) overlapped less in the presence of
 Leucauge web-building guests. Our novel experimental study highlights the
 importance of exploring synergistic effects in multi-species symbioses.
description: The data were collected from field experiments that manipulated
 the presence/absence of <em>Argyrodes</em> and
 <em>Leucage</em> guests on the webs of their
 <em>Cyrtophora</em> host.  The data were analysed using the R
 platform.  Details can be found in the published paper describing these
 experiments.
description: # Fitness effects of symbiotic relationships among arthropod predators
 [https://doi.org/10.5061/dryad.vq83bk40h](https://doi.org/10.5061/dryad.vq83bk40h) The data are derived from field experiments that manipulated the presence and absence of the spider guests *Argyrodes* spp. and *Leucage* spp. that cohabit with the host spider *Cyrtophora*. ## Description of the data and file structure The following provides details of the data files: ##### Host\_growth\_rate.csv **Site:** location of experiment **web_id:** identification of Cyrtophora web **date_start:** date the experiment started **date_end:** date the experiment finished **Arg:** experimental treatment with Argyrodes guests present or absent on the web of Cyrtophora **weight_start:** weight (g) of Cyrtophora host at the start of the experiment **weight_end:** weight (g) of Cyrtophora host at the end of the experiment **Leu_LeuWeb:** experimental treatment with (i) Leucage spider and her web present; (ii) Leucage spider absent but web present; (iii) Both Leucage spider and her web absent ##### Prey\_consum\_exp\_webs.csv **Site:** location of experiment **web_id:** identification of Cyrtophora web **date:** date of data collection **subject:** : identify of spider consuming prey (host = *Cyrtophera* spp.; guest = *Argyrodes* spp.) **Leu_LeuWeb:** experimental treatment with (i) Leucage spider and her web present; (ii) Leucage spider absent but web present; (iii) Both Leucage spider and her web absent **Size**: size range of prey (cm) ##### Prey\_count\_empty\_web.csv **Site:** location of experiment **web_id:** identification of Cyrtophora web **date:** date of data collection **web_surface:** area of host web (cm squared) **obs_time:** duration of observations (hours) **total_number:** number of prey items captured (per hour) ##### prey\_count\_exp\_webs.csv **Site:** location of experiment **web_id:** identification of Cyrtophora web **date_census:** date of census **date_start:** date experiment started **date_end:** date experiment ended **Arg:** experimental treatment with Argyrodes guests present or absent on the web of Cyrtophora **Leu_LeuWeb:** experimental treatment with (i) Leucage spider and her web present; (ii) Leucage spider absent but web present; (iii) Both Leucage spider and her web absent **web_surface:** area of host web (cm squared) **obs_time:** duration of observations (hours) **total_number:** number of prey items captured (per hour) ##### prey\_size\_bin\_exp\_webs.csv **Site:** location of experiment **web_id:** identification of Cyrtophora web **Arg:** experimental treatment with Argyrodes guests present or absent on the web of Cyrtophora **Leu_LeuWeb:** experimental treatment with (i) Leucage spider and her web present; (ii) Leucage spider absent but web present; (iii) Both Leucage spider and her web absent **Size:** size range of prey (cm) **Count:** number of observations ## Code/Software ##### field\_data\_analyses.html This file provides a full description of the analysis conducted in R.