An ultrastructural study of the mitochondria‐rich‘chloride‘cells from the gills of freshwater and seawater‐adapted Tilapia aurea subjected to a pesticide

Abstract

An electron microscopic description is presented of the mitochondria-rich ' chloride ' cells of the gill epithelium in the cichlid fish TiZapiu uurea kept in freshwater or adapted to seawater and injected with the pesticide p,p'DDT. The ' chloride ' cells may have a light or dark (electron dense) appearance. Dark ' chloride ' cells are more common in seawateradapted than in freshwater T. auren. Characteristic features of ' chloride ' cells include an abundance of mitochondria and anelaborate tubular reticulum, which communicates directly with the basal and lateral membranes of the cells. The apical portion of the ' chloride ' cells is often larger in seawater-adapted than in freshwater fish. Differences in ' chloride ' cell ultrastructure, which can possibly be associated with a response to different salinities, are described and discussed. No significant ultrastructural differences are detectable in response to injections of the pesticide.

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

“…However, apical pits of the chloride cells have already been observed in the gills of freshwater-adapted tilapias (Coleman & Han, 1977;Fishelson, 1980;Wendelaar Bonga & van der Meji, 1989;Maina, 1990). Furthermore, apical cavities opening into the gill chamber have been found in chloride cells of various species of freshwater stenohaline bony fishes (Kikuchi, 1977).…”

“…The presence of an apical crypt has been generally reported as a distinctive feature of chloride cells of marine teleosts or as a structural change that the chloride cells display when a euryhaline species is transferred from fresh to sea water (Laurent, 1984). However, apical pits of the chloride cells have already been observed in the gills of freshwater-adapted tilapias (Coleman & Han, 1977;Fishelson, 1980;Wendelaar Bonga & van der Meji, 1989;Maina, 1990). Furthermore, apical cavities opening into the gill chamber have been found in chloride cells of various species of freshwater stenohaline bony fishes (Kikuchi, 1977).…”

Degeneration and death, by apoptosis and necrosis, of the pavement and chloride cells in the gills of the teleost Oreochromis mossambicus

“…The branchial epithelial cells, in particular the chloride cells, are pleomorphic in ultra structure. The status of the accessory chloride cells, which have been considered to be developing or degenerating chlo ride cells (Coleman et al 1977;Sardet et al 1979;Hootman and Philpott 1980) or to be a functionally specific type of cell Chrétien and Pisam 1986), is still debatable.…”

The fish gill: site of action and model for toxic effects of environmental pollutants.

“…Similar morphological changes characterize exposures of fishes to fumigants such as methyl bromide (85); pyrethroid insecticides such as permethrin (86); detergents such as sodium lauryl sulfate (87,88); organochlorines such as DDT, endrin, and dieldrin; petroleum compounds such as phenol and naphthalene; organophosphates such as malathion and methylparathion; and carbamates such as sevin (32,89). Interestingly, injection of Tilapia aurea (adapted to either 2/3 sea water or fresh water) every 3 days with 10 mg/kg DDT for 30 days produced no abnormalities in the chloride cells (90).…”