Newly identified nematodes from the Great Salt Lake are associated with microbialites and specially adapted to hypersaline conditions
Data files
Feb 08, 2024 version files 181.91 KB
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GSL_Dryad.xlsx
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README.md
Abstract
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.
README
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).
Methods
Detailed methods can be found in the corresponding manuscript.