All are true regarding trematodes except:
Trematodes are unsegmented, leaf-like flat worms or helminthes with no body cavity. All of them are hermaphrodite except Schistosoma. They have two intermediate hosts, first is snail and second is fresh-water fish/ crab or water plants except schistosomes (one intermediate host) All schistosomes are acquired by skin penetration by cercariae unlike the other trematodes which are acquired by ingestion of metacercariae in poorly cooked fish or unwashed water plants.
They are hermaphrodites
Usually there are two intermediate hosts
Schistosoma hematobium infection is acquired through metacercaria ingestion
In Paragoninus westermani the second intermediate host is the crab
Parasitology Pa 2 (Helminthology)