Pristionchus nematodes occur frequently in diverse rotting vegetal substrates and are not exclusively necromenic, while Panagrellus redivivoides is found specifically in rotting fruits

PLoS One. 2018 Aug 3;13(8):e0200851. doi: 10.1371/journal.pone.0200851. eCollection 2018.

Abstract

The lifestyle and feeding habits of nematodes are highly diverse. Several species of Pristionchus (Nematoda: Diplogastridae), including Pristionchus pacificus, have been reported to be necromenic, i.e. to associate with beetles in their dauer diapause stage and wait until the death of their host to resume development and feed on microbes in the decomposing beetle corpse. We review the literature and suggest that the association of Pristionchus to beetles may be phoretic and not necessarily necromenic. The view that Pristionchus nematodes have a necromenic lifestyle is based on studies that have sought Pristionchus only by sampling live beetles. By surveying for nematode genera in different types of rotting vegetal matter, we found Pristionchus spp. at a similar high frequency as Caenorhabditis, often in large numbers and in feeding stages. Thus, these Pristionchus species may feed in decomposing vegetal matter. In addition, we report that one species of Panagrellus (Nematoda: Panagrolaimidae), Panagrellus redivivoides, is found in rotting fruits but not in rotting stems, with a likely association with Drosophila fruitflies. Based on our sampling and the observed distribution of feeding and dauer stages, we propose a life cycle for Pristionchus nematodes and Panagrellus redivivoides that is similar to that of C. elegans, whereby they feed on the microbial blooms on decomposing vegetal matter and are transported between food patches by coleopterans for Pristionchus spp., fruitflies for Panagrellus redivivoides and isopods and terrestrial molluscs for C. elegans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis / physiology
  • Coleoptera / parasitology
  • DNA, Helminth / genetics
  • Feeding Behavior / physiology
  • Female
  • Fruit / parasitology
  • Host-Parasite Interactions
  • Life Cycle Stages
  • Male
  • Rhabditida / genetics
  • Rhabditida / pathogenicity
  • Rhabditida / physiology*
  • Species Specificity

Substances

  • DNA, Helminth

Grants and funding

MAF and AR are supported by the Ecole Normale Superieure and the Centre National de la Recherche Scientifique. This work was supported by a National Science Foundation CAREER Award (MCB-1552101) to MA and the Ministry of Science and Technology, Taiwan and an Academia Sinica Career Development Grant to JW. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.