Since you did not specify the species I'm going to guess you mean Cestodes (tapeworms) and digeneans (flukes).
They can be found in rivers which have been polluted with feces or sewer sludge. Often found in farm land which was treated with raw sewage.
They can be transferred from animal to humans when the human eats uncooked infected meat. They can also infect humans who wash or bath in infected waters.
No it isn't. If it was a mammal it would have live babies and breastfeed its young, but a flatworm lays eggs.
flatworm
pink river dolphins live in the amazon
There isn't any kind of shark in the Amazon river. There is a kind of dolphin. Sharks are sea fish.
alligators
no is not correct! It is yes I just learned about it in science!
none at all
parasites digestive system they live on their host's
Tapeworms are a kind of flatworm. Most flatworms are not tapeworms.
they kill it
Beavers and muskrats
flat headed catfish live in the nothern hudson.