Ionic Regulation in the Brown Trout (Salmo Trutta L.)

1959 ◽  
Vol 36 (2) ◽  
pp. 227-252 ◽  
Author(s):  
MALCOLM S. GORDON
Keyword(s):  
Fresh Water ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Sea Water ◽  
Extracellular Volume ◽  
Water Levels ◽  
Blood Concentrations ◽  
Brown Trout Salmo Trutta ◽  
Muscle Concentration ◽  
Concentration Changes

1. The osmotic and ionic regulatory abilities of adults of the euryhaline brown trout (Salmo trutta) have been studied in experiments roughly duplicating the stresses of migration from fresh water to the sea. Brown trout will survive indefinitely in full sea water if acclimatized to it at rates inversely related to the temperature. 2. Blood serum samples have been analysed for Na, K, Cl, total P and δ; muscle samples for Na, K, Cl and total solids. Changes in the concentrations of these constituents following transfers from fresh water to 50% and 100% sea have been studied. Transfers were made throughout the year and at temperatures of 10° C. and 20° C. 3. Following transfers to 50% sea water at 20° C. blood concentrations rose significantly above fresh-water levels, but returned very nearly to these levels after about a week. Transfer from 50% sea water to 100% sea water at 20° C. caused the same sequence of changes. Transfer to 100% sea water at 20°C. was fatal, and associated with very high serum concentrations. Many fish survived transfer to 100% sea water at 10°C., however, and showed evidence of internal concentrations returning to fresh-water levels after 10 days. The brown trout is strongly homoiosmotic on a long-term basis. 4. Both survival and regulatory ability were lower during the summer. There were also seasonal variations in the blood and muscle concentrations of fish in a given state of acclimatization. 5. Muscle concentration changes closely paralleled blood changes. Extracellular volume remained constant, so muscle concentration changes were attributable to changes in intracellular water. The muscles did not act as storage sites for sodium and potassium.

Osmotic and Ionic Regulation in Scottish Brown Trout and Sea Trout (Salmo Trutta L.)

1959 ◽  
Vol 36 (2) ◽  
pp. 253-260
Author(s):  
MALCOLM S. GORDON
Keyword(s):  
Fresh Water ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Sea Water ◽  
Freezing Point ◽  
Water Levels ◽  
Acid Base Balance ◽  
Serum Samples ◽  
Water Stream ◽  
Sea Trout

1. Adult brown trout (Salmo trutta L.) of both sea-run (sea trout) and fresh-water stream (brown trout) forms were captured in the vicinity of Aberdeen and acclimatized to full-strength sea water for periods of up to 5 months. 2. Blood serum samples from these fish were analysed for freezing-point depression, chloride, sodium and potassium concentrations. 3. The patterns of regulation of these concentrations are very nearly the same in both forms. Brown trout and sea trout, at least in eastern Scotland, thus appear to be virtually identical in osmotic and ionic regulatory abilities. However, there is a possibility that there is a difference between the two forms with respect to mechanisms controlling blood acid-base balance. 4. The patterns of regulation shown by Scottish fish are the same as those shown by American hatchery fish treated similarly. The different populations of the species seem not to have diverged significantly from one another in this regard after many generations of more or less complete genetic isolation. 5. The species Salmo trutta is strongly homoiosmotic. Internal concentrations are either unchanged or increase by less than 10% above fresh-water levels with long-term acclimatizations to half and full sea water. The brown trout is the first salmonid species known to regulate so well.

scholarly journals The Impact of Hydropeaking on Juvenile Brown Trout (Salmo trutta) in a Norwegian Regulated River

2020 ◽  
Vol 12 (20) ◽  
pp. 8670
Author(s):  
Svein Jakob Saltveit ◽  
Åge Brabrand ◽  
Ana Juárez ◽  
Morten Stickler ◽  
Bjørn Otto Dønnum
Keyword(s):  
Power Plant ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Water Levels ◽  
Regulated River ◽  
Low Flow ◽  
High Survival ◽  
Power Station ◽  
Brown Trout Salmo Trutta ◽  
The Impact

The Norwegian electrical energy supply system is based on hydropower. The now deregulated energy market has led to increased use of hydropeaking production, leading to greater fluctuations in discharge and water levels below hydropower stations. The power station HOL 1, with an outlet to the Storåne River, is a large hydropeaking facility. With over 300 rapid flow increases and decreases per year since 2012, it is a river subjected to frequent hydropeaking. To quantify the stranding risk downstream of the power plant, the effect of a series of different turbine shutdown scenarios was simulated in an earlier study. The residual flow of 6 m3·s−1 and a full production of 66 m3·s−1 were considered as the baselines for the calculation of dewatered areas. A three-year study of juvenile fish density both upstream as a reference and downstream of the power plant was undertaken. There were very low densities or even an absence of brown trout (Salmo trutta) older than young-of-the-year (YoY) below the outlet of the power station, despite high densities of YoY in previous years. This is probably due to the large and rapid changes in flow below the power station. Hydropeaking has less impact on the earliest life stages of brown trout during spring and summer, as well as on spawning and egg development during winter. This is attributed spawning in late autumn occurring at a low flow seldom reached during hydropeaking. The high survival of YoY during the first summer and early autumn is likely due to a lower frequency of hydropeaking and higher residual flows, leaving a larger wetted area.

Occurrence of two species of Crepidostomum in brown trout (Salmo trutta L.) from north-east Ireland, with special reference to Crepidostomum metoecus Braun 1900

Parasitology ◽  
1955 ◽  
Vol 45 (1-2) ◽  
pp. 186-188 ◽  
Author(s):  
M. Pauline Corbett
Keyword(s):  
Special Reference ◽  
Fresh Water ◽  
Brown Trout ◽  
New Record ◽  
Salmo Trutta ◽  
Helminth Fauna ◽  
British Isles ◽  
North East ◽  
Brown Trout Salmo Trutta ◽  
Common Parasite

During the course of preliminary studies on the helminth fauna of local freshwater fishes two species of Crepidostomum, obtained from the intestine of brown trout, were identified as C. farionis (Müller) and C. metoecus Braun. Although C.farionis is a common parasite of the fresh-water salmonoid fishes of the Northern Hemisphere, in Ireland it has been recorded only from trout (Salmo trutta). The first Irish specimens were recorded by Southern (1912) as Stephanophiala laureata (Zeder), and came from fish from a stream in Clare Island and from the Owenwee River, Westport. Later, Vickers (1951) found that trout from the River Moyola, Co. Londonderry, and River Ravarnett, Co. Down, were infected with this species. Prior to the present study, C. farionis was the only representative of the genus to have been recorded from the British Isles. C. metoecus is therefore a new record, not only from Ireland, but from the British Isles as well. Elsewhere it is known to occur in Sweden [ = C. suecicum Nybelin, 1933], Austria, and possibly also in Thuringia, where cercariae were found which Nöller (1928) assigned to C. metoecus.

Sign in / Sign up

Export Citation Format

Share Document