title: Sexual dimorphism in the gills of the spawning river lamprey, Lampetra fluviatilis L.
abstract: Two types of mitochondria-rich cells were found in the interplatelet areas of the gills of sexually mature, male river lampreys. Type 1 cells (previolsy referred to as "male glandular cells") showed some ultrastructural characteristics in common with ion-transporting cells but were readily distinguished by large lipid structures with electron-lucent centres. Type 2 cells were found to be identical to the presumed ion-uptake cells during other stenohaline freshwater phases of the animal's life history. In the sexually mature female, only Type 2 cells were positively identified. This sexual dimorphism in gill structure is discussed in relation to the possible functions of the lamprey gill, with particular reference to ionic regulation.
mesh_terms: D000818:Animals; D001693:Biological Transport, Active; D005260:Female; D005399:Fishes / Q000033:anatomy & histology*; D005880:Gills / Q000648:ultrastructure*; D007477:Ions; D007798:Lampreys / Q000033:anatomy & histology*; D008297:Male; D008854:Microscopy, Electron; D008928:Mitochondria; D012737:Sex Factors
chemical_list: D007477:Ions