title: Localization of photoreceptors in the cercariae of Proterometra macrostoma (Trematoda: Azygiidae).
abstract: The swimming behavior of the cercaria of the digenetic trematode Proterometra macrostoma changes in response to light. However, this cercaria does not possess obvious eyes or eyespots. Using behavioral assays, we were able to show that both intact and distome-removed cercariae swim significantly greater vertical distances under dim, red light than under brighter, white light. Electrophysiological experiments confirmed this result and further showed that the transverse band of the tail, known to control cercariae swimming behavior, was necessary and sufficient for the display of the light-dependent swimming behavior. Together, these data show that the distome is not required for light-dependent swimming behavior in P. macrostoma cercariae and indirectly demonstrates the presence of photoreceptors in the transverse band of the cercaria tail.
authors.affiliation: Department of Biology, Berea College, Berea, Kentucky 40404, USA. marc_rowley@berea.edu
authors.forename: Marc
authors.initials: M
authors.lastname: Rowley
authors.forename: Kathryn
authors.initials: K
authors.lastname: Massana
authors.forename: Abigail
authors.initials: A
authors.lastname: Wier
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000528:radiation effects; D058487:Cercaria / Q000033:anatomy & histology / Q000502:physiology / Q000528:radiation effects; D008027:Light; D017956:Photoreceptor Cells, Invertebrate / Q000502:physiology / Q000648:ultrastructure*; D013550:Swimming; D014200:Trematoda / Q000033:anatomy & histology* / Q000502:physiology* / Q000528:radiation effects