title: A response to light in an adult encotyllabine (capsalid) monogenean from the pharyngeal tooth pads of some marine teleost fishes.
abstract: A response to light in an adult monogenean is reported for the first time. Living encotyllabine (capsalid) monogeneans, identified tentatively as Encotyllable caballeroi Velasquez, 1977, attached to pharyngeal tooth pads excised from two species of teleost fish, contracted rapidly when the intensity of the incident illumination was suddenly increased. Contracted individuals were immobile and largely concealed in crevices in the tooth pads. Parasites habituated to the higher light intensity after 60-100 s and re-extended their bodies and resumed activity. Contracted, immobile individuals re-extended prematurely if the light intensity was reduced during the habituation period. Detached parasites responded in the same way to abrupt changes in the illumination intensity. The possible significance of this response in relation to the biology of the hosts is briefly discussed.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich, U.K.
authors.forename: G C
authors.initials: GC
authors.lastname: Kearn
authors.forename: I D
authors.initials: ID
authors.lastname: Whittington
mesh_terms: D000818:Animals; D005393:Fish Diseases / Q000469:parasitology*; D005399:Fishes; D008027:Light; D014200:Trematoda / Q000528:radiation effects*; D014201:Trematode Infections / Q000469:parasitology / Q000662:veterinary*