title: [Vertical migration of cercariae of the littoral trematode Renicola thaidus (Trematoda: Renicolidae) in the water layer].
abstract: Vertical dispersion of the cercariae Renicola thaidus in the water layer was examined in experiments. Dispersion of larvae of 1 and 6 hours old were investigated in different conditions of illumination. It was found out that in the first hour of life the larvae both in light and dark conditions display a negative geotaxis. 6 hours later, the reaction alternates. Both in light and dark condition, the larvae show a positive geotaxis. This changes of vertical dispersion is the result of inversion of the reaction onto the gravitation, that depends on biology of cercariae examined.
mesh_terms: D000818:Animals; D003624:Darkness; D018522:Gravitropism; D007814:Larva / Q000502:physiology; D008018:Life Cycle Stages; D008027:Light; D009068:Movement; D013997:Time Factors; D014200:Trematoda / Q000254:growth & development / Q000502:physiology*; D014867:Water / Q000469:parasitology*
chemical_list: D014867:Water
vernacular_title: Vertikal'naia migratsiia v tolshche vody tserkariĭ morskoĭ litoral'noĭ trematody Renicola thaidus (Trematoda: Renicolidae).