Chronologie du cycle et étude des pseudo-kystesd'Heligmosomoides polygyrus polygyrus(Dujardin, 1845) (Trichostrongylina-Heligmosomoidea) chezApodemus flavicollisen France. Comparaison avec les espèces proches

G. N'Zobadila, J. Boyer, P.N. Vuong, M.C. Durette-Desset
1996 Parasite  
CHRONOLOGY AND STUDY OF THE PSEUDOCYSTS OF HELIGMOSOMOIDES POLYGYRUS (DUJARDIN, 1845) (TRICHOSTRONGYLINA-HELIGMOSOMOIDEA), A PARASITE OF APODEMUS FLAVICOLLIS IN FRANCE. COMPARISON WITH THE RELATED SPECIES The biology of the three species of Heligmosomidae, common among rodents in France, was studied in their respective natural hosts: Microtus arvalis for Heligmosomoides laevis, Apodemus flavicollis for Heligmosomoides polygyrus polygyrus and Clethrionomys glareolus for Heligmosomum mixtum. The
more » ... osomum mixtum. The morphogenesis had been studied in a first paper (N'Zobadila et al., 1996). This second paper deals with the chronology of the moults, the migrations in the vertebrate host and the formation of pseudocyst; in the three species, a number of larvae develop in a pseudocyst while the others do not leave the intestinal lumen, but, in both cases, the time required for the development remains similar. The Heligmosomidae have similar biological characteristics but which are more developed than those of the rodent parasites Nippostrongylinae (Heligmonellidae). However, there are some slight biological differences between them, in regard to their degree of morphological specialization. Thus the more primitive the species is, the more frequent is the formation of pseudocysts. The pseudocysts of the Heligmosomidae are interpreted as phenomena representing the genetic baggage of evolution whereas the Nippostrongylinae penetrate through the skin and migration through the lungs is necessary to reach the intestine, the Heligmosomidae, more evolved, penetrate orally and migration through the lungs becomes unnecessary. The facultative maturation of the larvae in a pseudocyst therefore may fulfil the necessity of the larva for somatic migration. Amongst the Trichostrongylidae of ruminants, the same phenomenon can result in a larval diapause, which could represent an adaptation process contributing to the survival of the worms when the environmental conditions, particularly climatic ones, are unfavourable.
doi:10.1051/parasite/1996033237 fatcat:5yz3fdsuujcuzmtrax56bgc4fm