Changes in the ultrastructure of the gills of the river lamprey, Lampetra fluviatilis (L.), during the anadromous spawning migration.
Two types of mitochondria-rich cells were found in the interplatelet areas of the gills of the migrating river lamprey. Both cell types are thought to be responsible for ion-transport across the gills. In the fresh-run migrant the gills are dominated by large, flask-shaped cells which show some ultrastructural similarities with the teleost chloride cell and have been tentatively referred to as ion-excretory cells. During the spawning migration the ion-excretory cells are replaced by smaller, mitochondria-rich cells which are similar in structure to the presumed ion-transporting cells in the ammocoete gill. They lack the tubular, smooth-membraned endoplasmic reticulum so characteristic of the lamprey ion-excretory cell and the teleost chloride cell and have been referred to as ion-uptake cells. The ion-uptake cells are found during the stenohaline, freshwater phases of the lamprey's life history. Ion-excretory cells are present during the periods of the life cycle when the animal is euryhaline. The possibility that the ion-excretory cells are also responsible for ion-uptake in fresh water is discussed.
D000818:Animals; D002712:Chlorides / Q000378:metabolism; D005399:Fishes / Q000033:anatomy & histology*; D005618:Fresh Water; D005880:Gills / Q000378:metabolism / Q000648:ultrastructure*; D007798:Lampreys / Q000033:anatomy & histology* / Q000378:metabolism; D008854:Microscopy, Electron; D014882:Water-Electrolyte Balance
D002712:Chlorides