*** Stable nitrogen isotope analysis of amino acids as a new tool to clarify complex parasite-host interactions within marine food webs***

Authors: Philip Riekenberg1*+, Tijs Joling1,2+, Lonneke L. IJsseldijk3, Andreas M. Waser2,4, Marcel van der Meer1, David W. Thieltges2 

(1) Department of Marine Microbiology & Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands
(2) Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, 
PO Box 59, 1790 AB Den Burg, Texel, The Netherlands
(3) Division of Pathology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3854 CL, Utrecht, The Netherlands
(4) Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Wadden Sea Station Sylt, Hafenstraße 43, 25992 List, Sylt, Germany

Corresponsding Author: P. Riekenberg phrieken@gmail.com

***General Introduction***
This data set contains the  nitrogen stable isotope values from amino acids contained in the parasite-host pairs collected from the Wadden and North Seas as described in the manuscript as part of Tijs Joling's MS project.

The data in this manuscript was produced in the Stable Isotope Laboratory in the Marine Microbiology and Biogeochemistry Department at NIOZ. 

***Test Equipment***
For compound specific isotope analysis of amino acid nitrogen, dried and homogenized tissue (2-5 mg) was lipid extracted, acid hydrolyzed, derivatized to pivaloyl- isopropyl esters and analysed for δ15N of AAs via gas 
chromatography-combustion isotope mass spectrometry using a Thermo Trace 1310 GC attached to Delta V Advantage isotope ratio mass spectrometer via an Isolink 2 following the method presented in Riekenberg, et al. (2020). 
δ15N values for 14 AAs are reported: alanine (Ala), aspartic acid (Asp), glutamic acid (Glu), glycine (Gly), leucine (Leu), lysine (Lys), isoleucine (Ile), methionine (Met), phenylalanine (Phe), proline (Pro), serine (Ser), 
threonine (Thr), tyrosine (Tyr), and valine (Val). Precision of amino acid δ15N values were <0.5‰ in standards run 10× per sequence for 14 AAs throughout the analytical runs supporting this study and sample duplicates 
had an average precision of 0.24‰. Normalization using two standard reference mixtures along with a reference spike of norleucine (Nle) added to all samples and standards which served as an internal reference calibration 
following the method from Yarnes and Herszage (2017).  

***Description of data***
lab; laboratory that analyzed the sample
lab_sample_id; lab sample ID
user_sample_id; User sample ID
sample_measurement_id; Bulk analysis of C and N 
collected_sample_mass; sample weight
instrumentation; Elemental analyzer
analysis_type; Bulk analysis of solid material
analysis_date; date and month of analysis
client_id; Who owns the sample
analytical_matrix; all tissues in this data set
primary_reference_material; Primary isotope reference material
preparation_step; sample preparations
preparation_step; sample preparations
material_type; generalized categories for sample ID of tissues
material_sample_id; Exact sample ID for tissue types
collection_source; All field samples
investigator_name; Philip Riekenberg
investigator_orcid; 0000-0002-6275-5762
investigator_email; phrieken@gmail.com
collection_locality; Wadden or North Sea
taxon_rank; ID is to species level
scientific_name; Genus species
amino acid_d15N; delta 15 N value for each amino acid
amino acid_error; standard deviation for the sample replicates of each amino acid
d15N_measurement_scale; against atmospheric N2
d15N_measurement_unit; per mille
d15N_error; standard deviation of the sample replicates for each amino acid analysis



