RT Journal Article
SR Electronic
T1 Ephemeral-habitat colonization and neotropical species richness of <em>Caenorhabditis</em> nematodes
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 142190
DO 10.1101/142190
A1 Céline Ferrari
A1 Romain Salle
A1 Nicolas Callemeyn-Torre
A1 Richard Jovelin
A1 Asher D. Cutter
A1 Christian Braendle
YR 2017
UL http://biorxiv.org/content/early/2017/06/01/142190.abstract
AB Background The drivers of species co-existence in local communities are especially enigmatic for assemblages of morphologically cryptic species. Here we characterize the colonization dynamics and abundance of nine species of Caenorhabditis nematodes in neotropical French Guiana, the most speciose known assemblage of this genus, with resource use overlap and notoriously similar outward morphology despite deep genomic divergence.Methods To characterize the dynamics and specificity of colonization and exploitation of ephemeral resource patches, we conducted manipulative field experiments and the largest sampling effort to date for Caenorhabditis outside of Europe. This effort provides the first in-depth quantitative analysis of substrate specificity for Caenorhabditis in natural, unperturbed habitats.Results We amassed a total of 626 strain isolates from nine species of Caenorhabditis among 2865 substrate samples. With the two new species described here (C. astrocarya and C. dolens), we estimate that our sampling procedures will discover few additional species of these microbivorous animals in this tropical rainforest system. We demonstrate experimentally that the two most prevalent species (C. nouraguensis and C. tropicalis) rapidly colonize fresh resource patches, whereas at least one rarer species shows specialist micro-habitat fidelity.Discussion Despite the potential to colonize rapidly, these ephemeral patchy resources of rotting fruits and flowers are likely to often remain uncolonized by Caenorhabditis prior to their complete decay, implying dispersal-limited resource exploitation. We hypothesize that a combination of rapid colonization, high ephemerality of resource patches, and species heterogeneity in degree of specialization on micro-habitats and life histories enables dynamic co-existence of so many morphologically cryptic species of Caenorhabditis.