The article discusses the tissue loss in corals invaded by acoelomorph flatworms. It states that the species and host specificity of epizoic acoelomorphs live in association with corals. It says that the zooxanthellate acoels of the genus Waminoa was the most recorded concern in 1990. It mentions that the acoels can harm corals by smothering them which hinders their respiration, sediment shedding, and feeding capacities.