DOI: 10.5061/dryad.nzs7h44wg
title: Newly identified nematodes from the Great Salt Lake are associated with microbialites and specially adapted to hypersaline conditions

description: Extreme environments enable the study of simplified food-webs and serve as
 models for evolutionary bottlenecks and early Earth ecology. We
 investigated the biodiversity of invertebrate meiofauna in the benthic
 zone of the Great Salt Lake (GSL), UT, one of the most hypersaline lake
 systems in the world. The hypersaline bays within the GSL are currently
 thought to support only two multicellular animals: brine fly larvae and
 brine shrimp. Here, we report the presence, habitat, and microbial
 interactions of novel free-living nematodes. Nematode diversity drops
 dramatically along a salinity gradient from a freshwater river into the
 south arm of the lake. In Gilbert Bay, nematodes primarily inhabit
 reef-like organosedimentary structures built by bacteria called
 microbialites. These structures likely provide a protective barrier to UV
 and aridity, and bacterial associations within them may support life in
 hypersaline environments. Notably, sampling from Owens Lake, another
 terminal lake in the Great Basin that lacks microbialites, did not recover
 nematodes from similar salinities. Phylogenetic divergence suggests that
 GSL nematodes represent previously undescribed members of the family
 Monhysteridae – one of the dominant fauna of the abyssal zone and deep-sea
 hydrothermal vents. These findings update our understanding of halophile
 ecosystems and the habitable limit of animals.
description: Detailed methods can be found in the corresponding
 manuscript. 
description: ## Great Salt Lake nematodes In this Dryad dataset, you'll find an
 excel file with 6 datasheets, each containing raw data from our manuscript
 on halophilic nematodes living in the Great Salt Lake, UT, published in
 Proceedings B in 2024. These datasheets include: * Envi Analysis: Each row
 here is a soil sample from one of our 6 sampling sites. Most of the
 variables are self explanatory (data sampled, time, etc). Temp, ORP, and
 Salinity *in situ* are measurements from the conductivity meter that were
 taken at the time of sampling in the lake. Volume (ml) is the volume of
 sample from which we extracted nematodes. N worms is the number of worms
 we found in the indicated volume. Abundance is the number of nematodes per
 100g of dry soil (calculated from N, wet weight, and dry weight). The
 salinity, ORP in columns R and S were extrapolated from the sample itself
 (see details in methods). The units from mass spec data are in mg per kg
 are ppm (1kg = 1 million mg). For Na for instance, the result would be
 17.8 g of Na per kg of sediment (or 1.78%). Pb1, Pb2, and Pb3 were 3
 independent measurements of lead via ICP-MS. Likewise, Cl and Cl_second
 (and SO4 and SO4_second) are independent mass spec measurements. Any NAs
 (here and across all these sheets) mean the data are not available. For
 instance, we only collected in-situ measurements of temperature, salinity,
 and ORP for each site during each collection date (not every sample); and
 we did not perform ICP-MS on samples collected after 2021; thus, the
 relevant cells are indicated as "NA". * Survival Assay: Each row
 here is a survival assay trial. We tested nematodes (*C. elegans* or *P.
 pacificus*, Farmington Bay worms, or Gilbert Bay worms) under different
 conditions and noted their survival. * GSL Worm Survival: Each row here is
 a plate of GSL worms in GSL water, each counted (N moving and N present)
 daily for 50 days. * GSL Sanger Sequences: These GSL nematode sequences
 are from Sanger Sequencing at the University of Utah Core Facilities. Each
 row here is a single nematode, its sequence data, and the BLAST results
 (NCBI). * Owens Lake Envi: Each row here is a soil sample from one of our
 6 sampling sites from Owens Lake. Most of the variables are self
 explanatory (data sampled, time, etc). Temp, ORP, and Salinity *in situ*
 are measurements from the conductivity meter that were taken at the time
 of sampling in the lake. Volume (ml) is the volume of sample from which we
 extracted nematodes. N worms is the number of worms we found in the
 indicated volume. Abundance is the number of nematodes per 100g of dry
 soil (calculated from N, wet weight, and dry weight). The salinity, ORP in
 columns R and S were extrapolated from the sample itself (see details in
 methods). * Owens Lake Sanger: These nematode sequences are from Sanger
 Sequencing at the University of Utah Core Facilities. Each row here is a
 single nematode, its sequence data, and the BLAST results (NCBI).
 You'll also find two R Markdown files with extensive annotations
 enabling anyone who wants to recreate all the analyses from the
 manuscript. * Rmd_for_Dryad.Rmd: This is my R script that I used to
 recreate the analyses in this paper. * 16s_analysis_for_Dryad.Rmd: This is
 my R script that I used to to the 16s analysis. The 16s data analysis
 script requires you to download additional sequence data from SRA
 (you'll find that info in the data availablity section in the
 manuscript).