He also distinguished earthworms from helminths (like tapeworms, flukes, and roundworms). They can also spread ticks, lungworms, tapeworms, flies and paramphistome flukes. Schistosoma is a genus of trematodes, commonly known as blood flukes. They can also spread ticks, lungworms, tapeworms, flies, and paramphistome flukes. Schistosoma mekongi is a species of trematodes, also known as flukes. Paragonimus is a genus of flukes (trematodes). It includes two groups of parasitic flatworms, known as flukes. It is characteristic of flatworms including the broad groups of tapeworms and flukes. The dugong's tail flukes and flippers are similar to those of dolphins. Scars from orca attacks found on the flukes of humpbacks are also used in identification. The sperm whale's flukes (tail lobes) are triangular and very thick. The parenchymal phase begins when excysted juvenile flukes penetrate the intestinal wall. The broad, centrally notched tail flukes rarely break the surface. Other causes include aflatoxin, non-alcoholic fatty liver disease and liver flukes. The varying patterns on the tail flukes distinguish individual animals.