Fine structure of chloride cells in freshwater‐ and seawater‐adapted Oreochromis niloticus (Linnaeus) and Oreochromis mossambicus (Peters)

Abstract

Ultrastructural features of branchial chloride cells in Oreochromis niloticus (Linnaeus) and 0. mossambicus (Peters) adapted to both fresh water and sea water werecompdred. In freshwater adapted fish of both species chloride cells showed similar morphological features. Multicellular complexes made of a mature chloride cell and one or more accessory cells sharing a single apical crypt have been observed. Whereas high percentages of 0. mossambicus survived at maximum salinity only a few individuals of 0. niloticus showed the capacity to adapt to sea water. In the seawater-adapted individuals of 0. niloficus and 0. rnossambicus the chloride cells showed a two-and three-fold increase in size. respectively. Most chloride cells are organized in large multicellular complcxcs with apical interdigitations of accessory cells and ' leaky junctions '. These results indicate that the difference in euryhalinity of the species studied is related to functional rather than structural differences.

Prolonged apoptosis in mitochondria-rich cells of tilapia (Oreochromis mossambicus) exposed to elevated salinity

“…This argument is also supported by a relatively slow increase in NKA activity in gills of tilapia following salinity transfer (Dange 1985;Hwang et al 1989). Likewise, signiWcant changes in MRC size only occurred several days after the onset of MRC apoptosis, which is consistent with previous studies based on MRC DASPMI staining and electron microscopy (Cioni et al 1991;Uchida et al 2000;Van Der Heijden et al 1997).…”

Acclimation trials of juvenile Italian sturgeon to different salinities: morpho‐physiological descriptors

“…An increased number and/or size of the interlamellar chloride cells is described for euryhaline teleosts during adaptation to SW (Laurent & Hebebi, 1989;Cioni et al, 1991;Avella et al, 1993). On the other hand, a degeneration and disappearance of lamellar chloride cells, that are linked to the ion pumping capacity of the gill in FW, was reported for the Atlantic salmon during its migration to the sea (Bornacin et al, 1987).…”

Branchial ionocyte organization and ion-transport protein expression in juvenile alewives acclimated to freshwater or seawater

“…We also observed variability in ionocyte abundance across the filament: ionocytes were concentrated on the trailing (afferent) edge. This has previously been reported in the hagfish Myxine glutinosa (Bartels, 1998), the sea lamprey Petromyzon marinus (Bartels et al, 1996), Atlantic stingray (Piermarini and Evans, 2000), Mozambique tilapia and the Nile tilapia Oreochromis niloticus (Cioni et al, 1991;van der Heijden et al, 1997), killifish (Katoh et al, 2001), the medaka Oryzias latipes (Sakamoto et al, 2001) and the chum salmon Oncorhynchus keta (Uchida et al, 1996). Ionocyte number, location and size often vary with salinity.…”