Alien Invaders: Larval flukes as an aid to teaching

Abstract

Few organisms have life cycles as elaborate or behaviour as complex as parasites. In this paper the biology of digenean trematodes and their larval stages is outlined. Like alien invaders with malevolent intent, these highly adapted organisms encounter and penetrate host tissues. Aspects of their life cycles truly surpass any creation of the Hollywood dream factory, a case of science fact being more bizarre than science fiction. The similarities between reality and the manifestations of the film industry can be employed to stimulate interest among students. Here, the use of non-pathogenic larval flukes in studies of parasite behaviour is encouraged, and a number of investigations suitable for students from GCSE to undergraduate level are suggested. The equipment required is commonly available in school laboratories. As trematode life cycles are quite diverse, the marine parasite Cryptocotyle lingua is used as an exemplar.