Substrate and Moisture Preferences of Terrestrial Isopods. C. Brett Basham Undergraduate in Conservational Biology Tennessee Tech. University Cookeville, TN 38501

Project Summary Problem: Terrestrial isopods, like their aquatic relatives use tracheae like gills to breath. In order for them to breathe properly they must be able to respond to changes in moisture levels. Problem: Terrestrial isopods, like their aquatic relatives use tracheae like gills to breath. In order for them to breathe properly they must be able to respond to changes in moisture levels. Objective: The objective of the experiment is to test their ability to detect different moisture levels and to document which moisture level / substrate they prefer. Objective: The objective of the experiment is to test their ability to detect different moisture levels and to document which moisture level / substrate they prefer.

Introduction Terrestrial isopods Terrestrial isopods Domain: Eukarya Kingdom: Animalia Phylum: Arthropoda Subphylum: Crustacea Class: Malacostraca Order: Isopoda Family: Armadillidiiae Species: Armadillidium vulgare

Introduction Cont. Terrestrial isopods are the only crustaceans that have totally abandoned an aquatic environment for a terrestrial one. (Brusca 1985) Terrestrial isopods are the only crustaceans that have totally abandoned an aquatic environment for a terrestrial one. (Brusca 1985) Isopods break down organic material, especially leaf matter and play an important role in the production of humus. (Rapp 2001) Isopods break down organic material, especially leaf matter and play an important role in the production of humus. (Rapp 2001) Young isopods emerge in the spring and walk from a few to over one thousand meters before establishing burrows of their own. (Baker 2005) Young isopods emerge in the spring and walk from a few to over one thousand meters before establishing burrows of their own. (Baker 2005)

Introduction Cont. Fossil evidence show that isopods occurred in the Late Jurassic and inhabited coastal mudflats. (Gaillard et al. 2005) Fossil evidence show that isopods occurred in the Late Jurassic and inhabited coastal mudflats. (Gaillard et al. 2005) Isopods are able to perceive the presence of toxic compounds and are able to escape from contaminated soil to clean soil. (Loureiro et al. 2005) Isopods are able to perceive the presence of toxic compounds and are able to escape from contaminated soil to clean soil. (Loureiro et al. 2005)

Objective & Hypothesis Statement Objective: To determine how isopods react to different moisture levels and substrates. Objective: To determine how isopods react to different moisture levels and substrates. Hypothesis: The isopods will show a preference for both moisture levels and substrates. Hypothesis: The isopods will show a preference for both moisture levels and substrates. Null Hypothesis: The isopods will show no preference. Null Hypothesis: The isopods will show no preference.

Methods and Materials Materials needed: Materials needed: - Petri dishes - filter paper - dark soil - red clay - sand - water - terrestrial isopods (30-40) - stopwatch Data form Data form

Methods There will be two separate experiments. There will be two separate experiments. The first experiment will test how the isopods respond to different moisture levels (dry, moist, and soaked) on a simple, artificial substrate. The second will test how they respond to the preferred moisture level of the first experiment on different natural substrates (dark soil, red clay, and sand). I will analyze the data from each experiment using the G-test, and then by using a chi squared table to determine if my findings are significant. I will analyze the data from each experiment using the G-test, and then by using a chi squared table to determine if my findings are significant.

Expected Results For both experiments the isopods will show a preference. For both experiments the isopods will show a preference. For the first experiment I predict they will prefer the moist substrate. For the second experiment I predict that they will have a preference for the dark soil.

Projected Timeline

Budget Salary- $500 Nonexpendable-$100 Expendable-$150 Indirect Costs-$75 Travel-$175

The End

Literature Cited Baker, M Experience influences settling behaviour in desert isopods, Hemilepistus reaumuri. Animal Behavior 69: Brusca, R The biology of terrestrial isopods. Science 230: 659 Gaillard, C., P. Hantzpergue, J. Vannier, A. Margerard, J. Mazin Isopod trackways from the Crayssac Lagerstatte, Upper Jurassic, France. Palaeontology 48: Loureiro, S., A. Soares, A. Nogueira Terrestrial avoidance behavior tests as screening tool to assess soil contamination. Environmental Pollution 138: Rapp, W The terrestrial isopods of Nebraska. Transactions of the Nebraska Academy of Sciences 27: 9