Population Biology of Daubaylia potomaca (Nematoda:Rhabditida) in Mallard Lake, North Carolina

Daubaylia potomaca is a unique nematode parasite that has a direct life cycle through the pulmonate snail Helisoma anceps with the adult female nematode being the infective stage. Found in all tissues and blood spaces, this parasite was ultimately found to decrease the life span of its snail host. Additionally, parasite-induced winter mortality of H. anceps caused by D. potomaca leads to a large recruiting event after the snails come out of torpor in March. Length analysis of D. potomaca leads to the possibility of the L3 being the infective stage, but more research needs to be performed in order to confirm this. Interactions of D. potomaca with a commensal oligochaete (Chaetogaster limnaei limnaei) and several trematode parasites, namely Echinostoma sp., revealed some interesting biotic interactions in the system. It was found that the presence of C. l. limnaei significantly increased the mean intensity of D. potomaca (P<0.001) in the snail hosts while the presence of Echinostoma sp. and rediae, significantly decreased the mean intensity of D. potomaca infection (P<0.04 and P<0.01, respectively). Echinostoma sp. and their rediae are known to compete with other parasites in the snail, and rediae are known predators of other macroinvertebrates. It was hypothesized that the rediae consume both juvenile and adult D. potomaca, thus reducing the mean intensity of the nematode. Furthermore, C. l. limnaei is known to feed on various stages of trematode parasites, including both Echinostoma sp. miracidia and cercariae, and thus aids in preventing trematode infection in the snail host. Therefore, the protective actions of C. l. limnaei against Echinostoma sp. indirectly increases the mean intensity of D. potomaca by allowing the nematode more space to live and develop as well as reduce its interactions with a predator.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2010

Author dc:creator

• Zimmermann, Michael

• Nematode

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10339/14785

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/14785