Thermal tolerance and the respiratory properties of isolated red muscle mitochondria were investigated in Oreochromis alcalicus grahami from the alkaline hot-springs, Lake Magadi, Kenya. Populations of O. a. grahami were resident in pools at 42.8 °C and migrated into water reaching temperatu...

Juvenile rainbow trout (Oncorhynchus mykiss) were exposed to 11 (control), 300 (medium), and 1000 mug Cu.g(1) (high) (as CuSO(4)5H(2)O) in the diet for 28 days at a daily ration of 4% wet body weight, with a background waterborne Cu concentration of 3 mug.L-1. There was no effect of dietary Cu on gr...

Exploitation of natural mineral deposits and subsequent re-deposition in aquatic environments at levels potentially harmful to biota necessitate regulation of environmental discharge of metals. Proper environmental regulation of metals requires adequate knowledge on the bioavailability and effects o...

Ecological risk assessment (ERA) of inorganic metals and metalloids (metals) must be specific to these substances and cannot be generic because most metals arc naturally occurring, some are essential, speciation affects bioavailability, and bioavailability is determined by both external environmenta...

Non-essential metals such as cadmium (Cd) accumulated in animal cells are envisaged to partition into potentially metal-sensitive compartments when detoxification capacity is exceeded. An understanding of intracellular metal partitioning is therefore important in delineation of the toxicologically r...

The thermostability of haemoglobin was measured in three species of fish living at different environmental temperatures (ET). The time (min) for 50% denaturation (T sub(1/2)d) of the haemoglobin at 2 mg ml super(-1) in 50 mM phosphate buffer, pH 7.3 was 46.4 plus or minus 1.7 for Oreochromis alcalic...

The present study examined the interactions between elevated dietary calcium (as ionic Ca2+ in the form of CaCl2 x 2H2O) and acute waterborne Cd exposure (50 microg/l as CdNO3 for 3 h) on whole body uptake and internal distribution of newly accumulated Cd, Ca2+, and Na+ in juvenile rainbow trout (On...

Rainbow trout Oncorhynchus mykiss fry in moderately hard water were exposed to control or high levels of dietary Cu (c. 6 and 580 ug Cu g food-1) at one of three levels of Na (1.5, 3.0 or 4.5%) in the diet, i.e. six experimental groups. Fish were fed a 4% body mass ration daily for 28 days and 10 in...

Waterborne Cu is toxic to Na(+) and Cl(-) regulation in freshwater fish, and Cu is taken up, at least in part, via the Na(+)-transport pathway in the gills. Therefore, we hypothesized that freshwater fish may mitigate the toxic effects of waterborne Cu by selecting a NaCl-enriched diet over a normal...

The kidneys of four freshwater teleost fish Oreochromis niloticus, Micropterus salmoides, Cyprinus carpio and Clarias mossambicus and one marine teleost, Chanos chanos, representing Perciformes (O. niloticus and M. salmoides) Ostariophysi (C. carpio, and C. mossambicus) and Salmoniformes (C. chanos)...