title: [Morphological changes in the retina of Pacific salmon Oncorhynchus masou fry in response to geomagnetic field compensation under conditions of normal illumination].
abstract: It is shown, for the first time, that in both migratory salmon fry Oncorhynchus masou, and in dwarf form of this species retina reaction changes after experimental geomagnetic field (GMF) compensation, and these changes were different in migratory salmon fry and in dwarfs. The reaction of various types of retina photoreceptors in migratory salmon fry to GMF compensation differs: if the rods and double cones perceive GMF compensation as an approach of darkness (scotopic reaction), single (as a rule, blue-sensitive) cones react to GMF compensation as a presentation of dark blue or (very seldom) of ultra-violet radiation. The retina of dwarf form of salmon reacts to GMF compensation as follows: the rods demonstrate light (photopic) reaction, and double (red-green-sensitive) cones--dark (scotopic) reaction. Single (dark blue-sensitive) cones react to GMF compensation as to bright dark blue light. Thus, the morphological picture of dwarf form of salmon retina under the given experimental conditions corresponds to perception of dark blue light. The initial conditions were different and corresponded to usual scattered day time light with illumination of about 7.5 luxes. GMF compensation does not seem to influence rods, while double, red-green cones react to it as to darkness, that is the fish does not perceive red and green light of a visible spectrum, and perceives only dark blue and, probably, ultraviolet by means of central dark blue-sensitive and additional cones. Thus, it is shown, that under conditions of usual day-time illumination salmon retina photoreceptors react to change of GMF, i.e. they play a role of magnetoreceptors.
authors.forename: A A
authors.initials: AA
authors.lastname: Maksimovich
authors.forename: S L
authors.initials: SL
authors.lastname: Kondrashev
authors.forename: V P
authors.initials: VP
authors.lastname: Gniubkina
mesh_terms: D000818:Animals; D008029:Lighting; D008280:Magnetics; D008297:Male; D017683:Oncorhynchus / Q000502:physiology*; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology* / Q000648:ultrastructure*; D012160:Retina / Q000166:cytology*