43 research outputs found
Seasonal maturation of Glypthelmins vitellinophilum (Trematoda: Digenea) in Lysapsus limellus (Anura: Pseudidae) from an Argentinian subtropical permanent pond
The evolutionary ecology of complex lifecycle parasites: linking phenomena with mechanisms
Many parasitic infections, including those of humans, are caused by complex lifecycle parasites (CLPs): parasites that sequentially infect different hosts over the course of their lifecycle. CLPs come from a wide range of taxonomic groups-from single-celled bacteria to multicellular flatworms-yet share many common features in their life histories. Theory tells us when CLPs should be favoured by selection, but more empirical studies are required in order to quantify the costs and benefits of having a complex lifecycle, especially in parasites that facultatively vary their lifecycle complexity. In this article, we identify ecological conditions that favour CLPs over their simple lifecycle counterparts and highlight how a complex lifecycle can alter transmission rate and trade-offs between growth and reproduction. We show that CLPs participate in dynamic host-parasite coevolution, as more mobile hosts can fuel CLP adaptation to less mobile hosts. Then, we argue that a more general understanding of the evolutionary ecology of CLPs is essential for the development of effective frameworks to manage the many diseases they cause. More research is needed identifying the genetics of infection mechanisms used by CLPs, particularly into the role of gene duplication and neofunctionalisation in lifecycle evolution. We propose that testing for signatures of selection in infection genes will reveal much about how and when complex lifecycles evolved, and will help quantify complex patterns of coevolution between CLPs and their various hosts. Finally, we emphasise four key areas where new research approaches will provide fertile opportunities to advance this field
Bearing of lake management on the parasite fauna of fishes
Results of investigations on the influence of introduction of various fish species to lake biocenosis on the parasite fauna of fishes are presented. Phytophagous fishes: Ctenopharyngodon idella, Hypophthalmichthys molitrix and Aristichthys nobilis, introduced to lakes Warniak and Dgał Wielki (Mazurian Lakeland) caused great changes in biocenoses of these lakes (destruction of aquatic plants followed by impoverishment of invertebrate fauna). An indirect bearing of these changes on the parasite fauna of native fishes was manifested either in a reduction of the quantity of some common parasites (Tylodelphys, Ergasilus) or in their increase (Ichthyocotylurus spp.). Some less common or numerous species of parasites showed a tendency to disappearance (e.g. acanthocephalans). The introduced fishes enriched the parasite fauna with 4 species. They were also susceptible to native parasite infections (Ergasilus, Diplostomum, Apharyngostrigea)