1. A highly significant linear correlation was found between glomerular filtration rate and urine flow rate in both freshwater and seawater trout. The percentage tubular reabsorption of water was approximately 33% greater in seawater trout than in freshwater trout. 2. As oxygen consumption increased, the urine flow rate increased in freshwater and seawater rainbow trout. The proportional increa...

Vitellogenin was obtained from three year-old vitellogenic trout. Two procedures of isolation were compared: dialysis against distilled water and ultracentrifugation in the density interval 1.21-1.28 g/ml. Similar patterns were observed by gel filtration and electrophoresis for both preparations of vitellogenin, indicating that electric charge and molecular weight were not modified by either pr...

1. Rainbow trout (Salmo gairdneri) of mean initial weight 15 g were given either a low-manganese or control diet containing 1.3 and 33 mg Mn/kg dry diet respectively. 2. Weight gains over a 24-week feeding period were the same for both groups of trout. 3. Hepatosomatic index, blood packed cell volume and haemoglobin concentration, plasma protein and the activities of aspartic aminotransferase (...

1. Replicate groups of rainbow trout (Salmo gairdneri) were given one of five experimental diets (diets 1-5) for 16 weeks. The diets contained different amounts of calcium, phosphorus and magnesium and were prepared so that there were three levels of Ca (g/kg): 14 (diet l) , 26 (diets 2 and 3) and 40 (diets 4 and 5) , Ca:P being approximately 1 : I in all diets. Diets 1, 2 and 4 had basal Mg le...

I. The possibility that costs of Ionic and osmotic regulation are different in fish was assessed using mortality rates of rainbow trout exposed to an ionically active substance, sodium chloride and a non-electrolyte. mannitol, in the ambient water. 2. A 24.hr LC,, of 175 mOsm was calculated from data for fish exposed to sodium chloride concns of 400.450. 500. 550. 600,650 and 700 mOsm. 3. Simil...

High unsteady (acceleration) performance of rainbow trout (L = 14-3 cm) and green sunfish (L = 8-o cm) was studied in response to electric shock stimulus. Acceleration movements were divisible into a preparatory stage 1 and a main propulsive stage 2. Locomotory behaviour varied between faststarts and turning manoeuvres. Taking the centre of mass for the stretched straight body as the reference ...