What are the disadvantages of living a parasitic life

Mistletoe  and other plants are parasitized. Many human diseases are caused by parasites (malaria, sleeping sickness etc) so this is clearly a disadvantage but humans can use parasites to their benefit. In short, a parasite is a disadvantage to its host but may play a number of other roles within the ecosystem.

the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.