Document Detail


Experimental population dynamics of Rhabdias bufonis (Nematoda) in toads (Bufo bufo): density-dependence in the primary infection.
MedLine Citation:
PMID:  1614734     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Density-dependence in worm establishment, numbers, biomass and larval production were examined in primary infections of 0, 10, 40, 80 and 160 larvae of the lung nematode, Rhabdias bufonis in the common toad, Bufo bufo. The infection procedure established 4 non-overlapping levels of infection which persisted until 6 weeks post-infection (p.i.), after which there was an overall decline up to 12 weeks p.i. Worm numbers had no direct effect on adult worm survival but temporal changes in worm weight were density-dependent. Adult worm establishment in the lungs declined significantly as the numbers of worms in the lungs increased. At the lowest exposure dose, 86% of the larvae administered reached maturity in the lungs while at the highest, only 37% did so. Also, the numbers of immature larvae outside the lungs increased as adult worm numbers increased. Both features provide evidence for a threshold limit to the numbers of worms maturing in the lungs. Worm numbers also affected larval output per host and per capita fecundity. A significant positive relationship between per capita fecundity and per capita worm weight suggested that density-dependence acted primarily to constrain the growth of individual worms. Finally, the constraints imposed on worm growth and fecundity were apparently relaxed when worm density decreased, providing evidence for density-dependent flexibility in per capita fecundity. Density-dependence in worm establishment and per capita fecundity are mechanisms which may potentially regulate this host-parasite interaction in the field. Both mechanisms may be functionally related to physical space limitations in the lungs, within which worms must compete for finite nutrients.
Authors:
C P Goater
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Parasitology     Volume:  104 Pt 1     ISSN:  0031-1820     ISO Abbreviation:  Parasitology     Publication Date:  1992 Feb 
Date Detail:
Created Date:  1992-07-30     Completed Date:  1992-07-30     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0401121     Medline TA:  Parasitology     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  179-87     Citation Subset:  IM    
Affiliation:
Zoologisches Museum, Universität Zürich, Switzerland.
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MeSH Terms
Descriptor/Qualifier:
Analysis of Variance
Animals
Bufo bufo / parasitology*
Larva / growth & development
Population Dynamics
Rhabdiasoidea / growth & development*
Strongyloidiasis / parasitology,  veterinary*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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