What structural features of flukes are associated with their lifestyle?

Flukes are parasitic representatives living in humans and animals. The most common hepatic fluke parasitizing the liver and biliary tract. Attachment to the substrate occurs due to the oral and abdominal suction cups. The glandular epithelium secretes a secret that protects the parasite from the destructive effects of the digestive juices of the host’s body. The integumentary epithelium contains small spines, which, together with suckers, hold the fluke’s body against the walls of the organ.