Baird Lab Index

Host-Associate Interactions in Caenorhabditis

Many terrestrial nematodes use other soil invertebrates for transport between microenvironments.  Such phoretic associations form when conditions favor dauer development over continued population growth.  They end when a more favorable microenvironment is reached or is created by the death of the invertebrate host.  These subparasitic associations share many features exhibited in true nematode parasitism; the infesting stage is the dauer larva, dauers exhibit 'nictation' behavior which in parasitc nematodes is correlated with an ambush strategy of host acquisition, and a degree of hsot specificity is exhibited by the infesting nematodes.

In the nematode genus of Caenorhabditis, approximately have of the species have known hosts.  Among these species is Caneorhabditis remanei, which is an associate of terrestrial isopods (pill bugs, etc.) and snails (Baird et al., 1992; Baird, 1999).   Our current, focus is to determine the prevalence of C. remanei-isopod associations.  Toward this end we are conducting a survey of isopods throughout Ohio.  In this survey, isopods collected from state parks are sacrificed to determine whether or not they are infested with C. remanei.  Our goals are to determine the geographic extent of C. remanei-isopod associations and to determine the host range of these associations.

Geographic Distribution of C. remanei - isopod associations in Ohio

A map of survey collection sites in Ohio.  Yellow sites are those in which C. remanei-isopod associations have been observed,  Red sites are those in which isopods are uninfested.  Thanks to the Ohio Department of Natural Resources and the Five Rivers MetroParks for permission to collect.
Isopod Hosts of C. remanei
Isopod Species
Host Status
Trachelipus rathkii
Cylisticus convexus
Armadillidium vulgare
Armadillidium nasatum
Porcellio scaber
Porcellio spinicornis