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Seasonal morphological variations in bird schistosomes
C Bayssade-Dufour1, D Jouet, J Rudolfova
1USM 602, Biologie parasitaire, Systématique et Evolution, MNHN, 61, rue Buffon,75231 Paris, France.
Parasite (Paris, France)
|September 30, 2006
Summary
This study investigated schistosomes in French wildfowl, finding morphological variations in Bilharziella and Dendritobilharzia. DNA analysis confirmed single species for each genus, Bilharziella polonica and Dendritobilharzia, despite observed differences.
Area of Science:
- Parasitology
- Systematic Zoology
- Molecular Biology
Background:
- Schistosomes are parasitic flatworms with complex life cycles.
- The genera Bilharziella and Dendritobilharzia are known parasites of wildfowl.
- Understanding schistosome diversity is crucial for host-parasite ecology.
Purpose of the Study:
- To contribute to the systematic understanding of Bilharziella and Dendritobilharzia.
- To investigate morphological variations within these schistosome genera in wildfowl.
- To clarify species identification using molecular data.
Main Methods:
- Necropsy of wildfowl (mallards, grey heron, mute swans) from Champagne-Ardenne, France.
- Morphological examination of collected schistosomes, focusing on male and female reproductive systems and spination.
- DNA sequencing for species-level identification and phylogenetic analysis.
Main Results:
- Morphological variations were observed in Bilharziella, suggesting multiple species, but DNA analysis confirmed them as Bilharziella polonica.
- Dendritobilharzia samples exhibited morphological differences from the type species D. pulverulenta, yet molecular analysis confirmed their identity.
- Parasitism by Bilharziella was found in mallards, grey herons, and mute swans, while Dendritobilharzia was found in a mute swan.
Conclusions:
- Morphological variations in Bilharziella and Dendritobilharzia are likely influenced by host factors, season, and parasite age, not indicative of distinct species.
- The systematic definitions of the genera Bilharziella and Dendritobilharzia were amended based on the findings.
- Molecular data is essential for accurate schistosome species identification, complementing traditional morphology.
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