DOI: 10.5061/dryad.sxksn03d4
title: Data from: Determining the optimal movement strategies in environments with heterogeneously distributed resources and toxicants

description: Environmental stress forces populations to move away from oppressive
 regions and look for desirable environments. Different species can respond
 to the same spatial distributions of resource and toxicant with distinct
 movement strategies. However, the optimal behavioral strategy may differ
 when a resource and a stressor occur simultaneously or if they distribute
 in different patterns. We compared the total abundance of two strains of
 Caenorhabditis elegans with different locomotion speeds as they forage in
 various spatial distributions of resource and toxicant. Informed by the
 experimental observations, we proposed a new two-state population model,
 wherein nutrient up-take and reproduction are modeled separately, as
 driven by the spatial distribution of resource and toxicant. We found that
 fast movers had an advantage when either the toxicant coverage or the
 overlap between toxicant and resource is increased. Also, to assess the
 effectiveness of designing refuges to conserve species in stressful cases,
 we compared different preferences of locations of refuge area according to
 movement strategies. Our mathematical model explained that fast movement
 enables individuals to consume resources at one location and reproduce at
 a separate location to avoid the toxicant-induced reduction in
 reproduction rate, which underlined its observed advantage in certain
 experimental settings. This work provided a better model to predict how
 species with different movement strategies respond to environmental
 stressors in natural systems.
description: Strains. Two strains with random (e.g. with defects in directed)
 movement were used in this study—MIA471 <em>tax-2(p694)
 I</em>; <em>egl-4(n478) IV</em> and MIA472
 <em>tax-2(p694) I</em>;<em> pdfr-1(ok3425)
 III</em>. MIA471 is a “roamer” strain that has a faster movement
 rate than MIA472, which is a “dweller” strain.
 <em>Heterogeneous Environments of Resources and Toxicants.
 We used square petri plates (100 mm x 100 mm) to design a variety of
 distributions of resources (E. coli) and toxicants
 (CuSO<sub>4</sub>·5H<sub>2</sub>O). </em> <em>Population Counting. </em>Initially, three L4 worms were added at the center of each petri dish (between rows C and D, and columns 3 and 4). All the experimental plates were kept in a 20 °C incubator for approximately 120 hours, the amount of time it takes for the majority of the worms to reach a size easily counted under a microscope (above L3 stage) before the food is depleted. The abundance of <em>C. elegans</em> (stage L3 and above) within each of the twelve sections were counted and recorded (n = 280).
description: # Determining the optimal movement strategies in environments with
 heterogeneously distributed resources and toxicants
 [https://doi.org/10.5061/dryad.sxksn03d4](https://doi.org/10.5061/dryad.sxksn03d4) ## Description of the data and file structure Population Counting. Initially, three L4 worms were added at the center of each petri dish (between rows C and D, and columns 3 and 4). All the experimental plates were kept in a 20 °C incubator for approximately 120 hours, the amount of time it takes for the majority of the worms to reach a size easily counted under a microscope (above L3 stage) before the food is depleted. After this time had passed, the experimental plates were moved into a refrigerator (4 °C) for about 30 minutes to let the low temperature slow the movements of the worms, making them easier to count. The abundance of *C. elegans* (stage L3 and above) within each of the twelve sections was counted and recorded (n = 280). ### Files and variables #### File: FinalDatasheet.xlsx **Description:** This dataset contains the data required to replicate analyses in Baragary et al., ##### Variables * Data. Date of data collection * ID. Each environment has 5 replicates (A-E) * Plate.environment: Experimental treatments/environments. “1” indicates a column with only *E. coli* food resources, “2” indicates a column with only Cu2+ toxicants, and “3” indicates a column with both *E. coli* food resources and Cu2+ toxicants. * Strain. Worm strain * Locomotion: locomotion speed of strains, H: high locomotion, L: low locomotion. * C1T: Column 1 top half * C1B: Column 1 bottom half * C2T: Column 2 top half * C2B: Column 2 bottom half * C3T: Column 3 top half * C3B: Column 3 bottom half * C4T: Column 4 top half * C4B: Column 4 bottom half * C5T: Column 5 top half * C5B: Column 5 bottom half * C6T: Column 6 top half * C6B: Column 6 bottom half * Resource: 0: No resource, 1: With resource * Toxicant: 0: No Toxicant, 1: With Toxicant * Total: Total population ## Code/software This dataset contains the matlab code: toxin_patch.m required to replicate analyses in Baragary et al., ## Access information Other publicly accessible locations of the data: * None Data was derived from the following sources: * Matlab