caa a22 4500 469097027 CHVBK 20180323133034.0 cr unu---uuuuu 170328e19920401xx s 000 0 eng 10.1007/BF00317160 doi (NATIONALLICENCE)springer-10.1007/BF00317160 Johnson Steven Museum of Natural History, The University of Kansas, 66045-2454, Lawrence, KS, USA aut Parasite-induced parthenogenesis in a freshwater snail: stable, persistent patterns of parasitism [Elektronische Daten] [Steven Johnson] Summary: The role of parasites in the evolution of host reproductive modes has gained renewed interest in evolutionary ecology. It was previously argued that obligate parthenogenesis (all-female reproduction) arose in a freshwater snail, Campeloma decisum, as a consequence of severe sperm limitation caused by an unencysted trematode, Leucochloridiomorpha constantiae. In the present study, certain conditions are examined for parasitic castration to account for the maintenance of parthenogenesis: the spatial patterns of the prevalence and intensity of infection on a broad geographical scale and its relationship to host genotype; the recovery from infection after isolation from sources of infection; age-related patterns of infections; and the effects of L. constantiae on snail fecundity. In contrast to the common pattern of the aggregated distribution of parasites within host populations, many snail populations with high prevalence and intensity of infection have non-aggregated parasite distributions. Clonal genotype of the host explained little of the variation in intensity and prevalence of infection by the parasite. Female snails maintained similar prevalence and intensity of infection after isolation, and individuals accumulated parasites throughout their lifespan, both of which suggest there is no effective immune response to infection by L. constantiae. Snail fecundity is not significantly influenced by the intensity of infection. These results suggest that L. constantiae may have represented a strong selective force against males during the initial introduction of this parasite into sexual snail populations because of the persistent nature of infection. Springer-Verlag, 1992 Campeloma decisum nationallicence Parasitic castration nationallicence Parthenogenesis nationallicence Red Queen nationallicence Trematodes nationallicence Oecologia Springer-Verlag 89/4(1992-04-01), 533-541 0029-8549 89:4<533 1992 89 442 https://doi.org/10.1007/BF00317160 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00317160 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Johnson Steven Museum of Natural History, The University of Kansas, 66045-2454, Lawrence, KS, USA aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 89/4(1992-04-01), 533-541 0029-8549 89:4<533 1992 89 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer