Adult worms measure usually 10 mm and they are located in the lungs.

H. cylindracea develops through 2 intermediate hosts: the first, a freshwater snail, the second, a water beetle.

[2] Adult worms are usually 10 mm long and they have elongate, cylindrical body.

Eggs are dark brown in colour and measures 220 μm.

[3] First intermediate host is snail from family Lymnaeidae, i.e. Galba truncatula, Lymnaea palustris, Radix spp.