title: Variations in the presence of chloride cells in the gills  of lampreys (Petromyzontiformes) and their evolutionary  implications.
abstract: Although confined to fresh water, non-parasitic species of lampreys and the landlocked parasitic sea lamprey, all of which were derived relatively recently from an adromous ancestors, still develop chloride cells, whose function in their ancestors was for osmoregulation in marine waters during the adult parasitic phase. In contrast, such cells are not developed by the non-parasitic least brook lamprey Lampetra aepyptera, which has been separated from its ancestor for >2 million years, nor by the freshwater parasitic species of the genus Ichthyomyzon. The length of time that a non-parasitic species or landlocked parasitic form or species has spent in fresh water is thus considered the overriding factor determining whether chloride cells are developed by those lampreys.
authors.affiliation: Institut für Funktionelle und Angewandte Anatomie, Medizinische Hochschule Hannover, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Bartels
authors.forename: M F
authors.initials: MF
authors.lastname: Docker
authors.forename: M
authors.initials: M
authors.lastname: Krappe
authors.forename: M M
authors.initials: MM
authors.lastname: White
authors.forename: C
authors.initials: C
authors.lastname: Wrede
authors.forename: I C
authors.initials: IC
authors.lastname: Potter
mesh_terms: D000818:Animals; D005075:Biological Evolution; D005618:Fresh Water; D005880:Gills / Q000166:cytology*; D007798:Lampreys / Q000033:anatomy & histology* / Q000502:physiology; D008675:Metamorphosis, Biological; D064587:Osmoregulation