DOI: 10.5061/dryad.2bvq83bmp
title: Parasitism in ecosystem engineer species: a key factor controlling marine ecosystem functioning

description: 1. Although parasites represent a substantial part of marine communities’
 biomass and diversity, their influence on ecosystem functioning,
 especially via the modification of host behaviour, remains largely
 unknown. Here, we explored the effects of the bopyrid ectoparasite Gyge
 branchialis on the engineering activities of the thalassinid crustacean
 Upogebia pusilla and the cascading effects on intertidal ecosystem
 processes (e.g. sediment bioturbation) and functions (e.g. nutrient
 regeneration). 2. Laboratory experiments revealed that the overall
 activity level of parasitized mud shrimp is reduced by a factor 3.3 due to
 a decrease in time allocated to burrowing and ventilating activities (by a
 factor 1.9 and 2.9 respectively). 3. Decrease in activity level led to
 strong reductions of bioturbation rates and biogeochemical fluxes at the
 sediment-water interface. 4. Given the worldwide distribution of mud
 shrimp and their key role in biogeochemical processes, parasite-mediated
 alteration of their engineering behaviour has undoubtedly broad ecological
 impacts on marine coastal systems functioning. 5. Our results illustrate
 further the need to consider host-parasite interactions (including
 trait-mediated indirect effects) when assessing the contribution of
 species to ecosystem properties, functions and services.
description: For more details, please see section 2. Materials and methods in
 the paper.
description: Data are organized in five
 tabular data files (.txt files; separator = tab; decimal = .)
 Information on the
 experimental design (seasons and treatments) can be found in the section
 2.1. Field sampling and experimental design in the paper.
 <strong>Data on the proportion of time allocated
 to identified behaviours </strong>(activity.txt) The data file
 contains the proportion of time (in %) allocated to the four identified
 behaviours (i.e. "Walking", "Burrowing",
 "Ventilating" and "Resting") of parasitized (i.e.
 infested by the ectoparasite <em>Gyge branchialis</em>) and
 non-parasitized (i.e. not infested by <em>Gyge
 branchialis</em>) mud shrimp (<em>Upogebia
 pusilla</em>). Since mud shrimp were not visible enough during
 wintertime, this file includes only data from summertime (see section 3.1.
 Behaviour in the paper for more details). Please note that the
 recording duration of mud shrimp behaviour was 72 hours for each
 replicate. Therefore, the data (in %) can be easily translate in time
 data. <strong>Data on burrow
 characteristics </strong>(burrow_characteristics.txt)
 The data
 file contains the number of burrow openings at the sediment surface
 ("opening" in the file), the number of turning chamber
 ("chamber" in the file), the vertical extension of the burrow 
 (in cm; "depth" in the file), the total lenght of the burrow (in
 cm; "length" in the file), the thickness of the reworked
 sediment layer surrounding the burrow wall (in cm; "trs" in the
 file), the volume of reworked sediment surrounding the burrow (in
 cm<sup>3</sup>; "brs" in the file) and the volume of
 sediment expelled onto the sediment surface (in
 cm<sup>3</sup>; "ves" in the file). These variables
 have been counted and measured at the begining of experiments (t0)
 and after four (t4) and thrity (t30) days in winter and summer for control
 (without mud shrimp), parasitized and non-parasitized mud
 shrimp. Explanations can be found in the section 2.3.1. Sediment reworking
 in the paper. <strong>Data on sediment reworking
 rates </strong>(sediment_reworking.txt) The data file
 contains the output of the biodiffusion-bioadvection transport model (see
 section 2.3.1. Sediment reworking in the paper for more details) for
 control (without mud shrimp), parasitized and non-parasitized mud shrimp
 in winter and summer. It includes biodiffusion
 (D<sub>b </sub>in cm<sup>2</sup>
 y<sup>-1</sup>; "db" in the file) and bioadvection
 (Vb in cm y<sup>-1</sup>; "vb" in the
 file) coefficients. <strong>Data on bioirrigation
 rates </strong>(bioirrigation.txt) The data file
 contains the output of the bioirrigation model (see section 2.3.2.
 Bioirrigation in the paper for more details) for control (treatment
 "seagrass" in the file), parasitized and non-parasitized mud
 shrimp in winter and summer. It includes bioirrigation rate (Q in mL
 h<sup>-1</sup>; "q" in the file). Explanations can
 be found in the section 2.3.2. Bioirrigation in the paper.
 <strong>Data on benthic
 fluxes </strong>(benthic_fluxes.txt) The data file
 contains the flux (in mmol m<sup>-2</sup>
 d<sup>-1</sup>) of oxygen ("o2" in the file),
 ammonium ("nh4" in the file), nitrate ("no3" in the
 file) and dissolved silicate ("dsi" in the file) at the sediment
 water interface for control (treatment "seagrass" in the file),
 parasitized and non-parasitized mud shrimp in winter and summer. It also
 includes the respiration rate (in mmol m<sup>-2</sup>
 d<sup>-1</sup>) of parasitized ("respp" in the file)
 and non-parasitized ("respnp" in the file) mud shrimp in winter
 and summer, as well as excretion rate (in mmol m<sup>-2</sup>
 d<sup>-1</sup>) of parasitized (treatment "excp" in
 the file) and non-parasitized (treatment "excnp" in the
 file) mud shrimp in winter and summer.