"Cercaria mirabilis ", a trematode, has an especially large larval stage ( known as a cercarium ) which looks much like a small crustacean or mosquito larva.
22.
In 1786, O . F . M�ller gave a more complete description of the organism, which he named " Cercaria viridis ", noting its distinctive color and changeable body shape.
23.
Cercariae are infective to the second host in the life cycle, and infection may occur passively ( e . g ., a fish consumes a cercaria ) or actively ( the cercaria penetrates the fish ).
24.
Cercariae are infective to the second host in the life cycle, and infection may occur passively ( e . g ., a fish consumes a cercaria ) or actively ( the cercaria penetrates the fish ).
25.
In some species ( for example " Ribeiroia " ) the cercaria encysts, and waits until the host is eaten by a third host, in whose gut it emerges and develops into an adult.
26.
The name " Bucephalus ", meaning " ox head ", was originally applied to the genus " Bucephalus " because of the horn-like appearance of the forked tail ( furcae ) of its cercaria larva.
27.
Bucephalid cercaria larva from Ernst Haeckel's " Kunstformen der Natur " ( 1904 ) : The tail's furcae give the impression of horns, hence the genus name " Bucephalus " meaning " ox head ".
