Digeneans

Some articles on digenean, digeneans:

Digenea - Life Cycles
... array of variation on the complex digenean life cycle, and plasticity in this trait is probably a key to the group's success ... This has led to the inference that the ancestral digenean was a mollusc parasite and that vertebrate hosts were added subsequently ... of sexual and asexual generations is an important feature of digeneans ...
Digenea - Morphology - Digestive System
... As adults, most digeneans possess a terminal or subterminal mouth, a muscular pharynx that provides the force for ingesting food, and a forked, blind digestive system consisting of two ... Digeneans are also capable of direct nutrient uptake through the tegument by pinocytosis and phagocytosis by the syncitium ... Most adult digeneans occur in the vertebrate alimentary canal or its associated organs, where they most often graze on contents of the lumen (e.g ...
Digenea - Evolution
... for some time, but there appears general agreement that the proto-digenean was a parasite of a mollusc, possibly of the mantle cavity ... Evidence for this comes from the ubiquity of molluscs as first intermediate hosts for digeneans, and the fact that most aspidogastreans (the sister group to the Digenea) also have mollusc associations ... It is thought that the early trematodes (the collective name for digeneans and aspidogastreans) likely evolved from rhabdocoel turbellarians that colonised the open mantle cavity of early molluscs ...
Flatworm - Major Subgroups - Trematoda - Digenea
... Although the name "Digeneans" means "two generations", most have very complex life cycles with up to seven stages, depending on what combinations of environments the early stages encounter ... Individual adult digeneans are of a single sex, and in some species, slender females live in enclosed grooves that run along the bodies of the males, and partially emerge to lay eggs ... Adult digeneans can live without oxygen for long periods ...