Formation d'éléments reproducteurs endogènes chez <i>Histriculus similis</i> (Ciliophora Hypotrichida)

Dans ce travail, nous décrivons la formation d'éléments reproducteurs endogènes chez le Cilié Histriculus similis. Nous donnons également le schéma de son cyle vital complet. Parallelement à la reproduction classique par bipartition, il existe aussi un autre mode de reproduction asexuel chez certaines espèces de ce groupe

Impact of simulated nitrogen pollution on heathland microfauna, mesofauna and plants

Deposition of reactive nitrogen derived from intensive agriculture and industrial processes is a major threat to biodiversity and ecosystem services around the world; however our knowledge of the impacts of nitrogen is restricted to a very limited range of organisms. Here we examine the response of groups of microfauna (testate amoebae), mesofauna (enchytraeid worms) and plants to ammonium nitrate application in the Ruabon heathland long-term experiment. Plant data showed significant differences between treatments, particularly characterised by a loss of bryophytes in nitrogen-treated plots, by contrast enchytraeids showed a non-significant increase in abundance in response to treatment. Testate amoebae showed no significant changes in abundance or inferred biomass but significant changes in community structure with a reduced abundance of Corythion dubium, interpreted as a response to the loss of bryophytes. Our results suggest that simple indices of plant community may have value for bioindication while the bioindication value of testate amoebae and enchytraeids is not clearly demonstrated

Evidence from testate amoebae for changes in some local hydrological conditions between c. 5000 BP and c. 3800 BP on Edgeøya (Svalbard)

The study of a subfossil peat from the northwestern part of Edgeøya (Svalbard) enabled a reconstruction of the changes in the testate amoebae communities from c. 5000 BP to c. 3800 BP to be made. Two stratigraphical zones are recognized. The ecological interpretation of these sequences revealed rather humid and unstable hydrological conditions at the bog surface in the oldest zone, which presumably lasted until about 45004300 BP. The communities in the upper zone indicated a more stable and drier environment

E6. Recherche des Thécamoébiens

Chardez D., Lambert José. E6. Recherche des Thécamoébiens. In: Nouvelles archives du Muséum d'histoire naturelle de Lyon, tome 26, 1988. pp. 13-17

E6. Recherche des Thécamoébiens

Chardez D., Lambert José. E6. Recherche des Thécamoébiens. In: Nouvelles archives du Muséum d'histoire naturelle de Lyon, tome 26, 1988. pp. 13-17