HOW DORMANCY STRATEGIES IMPACT COMMUNITY ASSEMBLY AND GENETIC STRUCTURE OF ROCK POOL TARDIGRADES

As ephemeral aquatic habitats face frequent desiccation, survival strategies are a necessity for organisms inhabiting them. Limno-terrestrial tardigrades are exemplary in this regard, as most are capable of anhydrobiosis while others encyst. There is likely a difference in efficiency, however, as encystment requires more energy to produce multiple layers of cuticle, and there is a shorter window to ‘escape in time’ due to its longer duration. These differences may influence community assembly and genetic structure of populations by facilitating or hindering dispersal and gene flow via anemochory. We aim to characterize (1) community composition of rock pools at two regional protected sites and (2) population structure of two tardigrade species, anhydrobiotic Mesobiotus huecoensis and encysting Pseudobiotus kathmanae. We hypothesize that M. huecoensis will have greater dispersal potential, resulting in lower genetic distances. We compared genetic variation within and among populations using two molecular markers (ITS2, COI). Initial findings show minimal genetic difference among three populations of P. kathmanae based on ITS2 region divergence (0.13%). Phylogenetic analyses using COI sequences (n=23) with 2.3% divergence, reveal clades that are not clustered by rock pool, suggesting that encysting individuals are not dispersal limited. Bdelloid rotifers were dominant in all rock pools; tardigrade species did not co-occur. Further genetic analysis of both species will confirm how dormancy strategies and dispersal ability shape community development and evolutionary processes.

Presentation Preference: Poster

Primary Presenter: Michael Matthews, University of Texas at El Paso (mamatthews5@utep.edu)

Authors:

Michael Matthews, University of Texas at El Paso  (mamatthews5@utep.edu)

Matteo Vecchi, Polish Academy of Sciences  (matteo.vecchi15@gmail.com)

Elizabeth Walsh, University of Texas at El Paso  (ewalsh@utep.edu)