Influence of Varying pH and some Inorganic Cations on the Perivitelline Potential of Eggs of Atlantic Salmon (Salmo salar)

1984 ◽  
Vol 41 (7) ◽  
pp. 1066-1069 ◽  
Author(s):  
R. H. Peterson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Incubation Medium ◽  
Ambient Medium ◽  
Ionic Composition ◽  
Potential Difference ◽  
Nernst Equation ◽  
Inorganic Cations ◽  
Atlantic Salmon Salmo Salar ◽  
Perivitelline Fluid

A potential difference is maintained between the perivitelline fluid of the Atlantic salmon (Salmo salar) egg and the incubation medium. The magnitude of this potential difference depends on the ionic composition of the incubation medium; it exhibits a maximal negativity in deionized water, then depolarizes, and finally reverses in sign as the ionic content of the incubation medium is raised. The potential difference obeys the Nernst relationship over a limited concentration range of H+, Ca2+, and Mg2+ (10−5 to 10−3M). The maximal change in potential difference with change in Na+ and K+ concentrations is less than that predicted by the Nernst equation. The potential difference permits calculation of the degree of concentration of cations in the perivitelline fluid over that of the ambient medium. Depolarizing the perivitelline potential by lowering the ambient pH will result in losses of other cations from the perivitelline fluid.

Inhibition of Atlantic Salmon (Salmo salar) Hatching at Low pH

1980 ◽  
Vol 37 (5) ◽  
pp. 770-774 ◽  
Author(s):  
R. H. Peterson ◽  
P. G. Daye ◽  
J. L. Metcalfe
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Low Ph ◽  
Hatching Enzyme ◽  
Atlantic Salmon Salmo Salar ◽  
Salmon Eggs ◽  
Perivitelline Fluid ◽  
Eye Pigmentation ◽  
Ambient Levels

Hatching of Atlantic salmon (Salmo salar) eggs was delayed or prevented if they were exposed to water of lowered pH (4.0–5.5) after eye pigmentation had developed. Hatching subsequently could be induced by returning eggs to normal pH levels (6.6–6.8). Perivitelline pH fell rapidly to near ambient levels when eggs were exposed to low pH. It is suggested that the observed effects on hatching were due to inhibition of the hatching enzyme, chorionase.Key words: Atlantic salmon, eggs, pH, perivitelline fluid, chorionase

Effects of Low Environmental pH on the Survival, Growth, and ionic Composition of Postemergent Atlantic Salmon (Salmo salar)

1985 ◽  
Vol 42 (4) ◽  
pp. 768-775 ◽  
Author(s):  
Gilles L. Lacroix ◽  
D. James Gordon ◽  
Dana J. Johnston
Keyword(s):  
Nova Scotia ◽  
Atlantic Salmon ◽  
River Water ◽  
Salmo Salar ◽  
Ionic Composition ◽  
Low Ph ◽  
Atlantic Salmon Salmo Salar ◽  
Flow Through ◽  
Composition Changes

Postemergent Atlantic salmon (Salmo salar) were reared during the early feeding phase in the soft, acidic water of the Westfield River (mean pH 5.0) in Nova Scotia. The fry were held in a flow-through system of tanks in situ and were fed a hatchery diet. Bioassays were also conducted in river water treated with limestone (mean pH 6.1) to provide a control. Cumulative mortality of fry after 30 d in the tanks was 70% at pH 5.0 and only 4% at pH 6.1. Fry in untreated river water were inactive, ingested little food, and lost weight (approximately 25%) during the first 15 d of exposure. Large increases in body [Ca2+] and [Na+] were observed in fry at both pH levels during that time, but the increase in [Ca2+] lagged and that in [Na+] was less in fry at low pH. Deaths occurred 15–30 d after swim-up and dead fry were all severely emaciated, indicating that deaths were probably from starvation. Although there were differences in ionic composition changes in fry held at pH 5.0 compared with control, no major depletion of body ionic reserves occurred relative to initial concentrations. Surviving fry at pH 5.0 developed a tolerance after 25 d and had growth rates, condition factors, and ionic concentrations similar to those of fry in treated water. The mortality of fry during the transition to exogenous feeding, in response to low pH stress in soft water, is probably responsible for reduced recruitment and the decline or loss of salmon stocks in this and other acidic rivers of Nova Scotia.

Plasma ionic composition of the Atlantic salmon (Salmo salar), white sucker (Catostomus commersoni), and alewife (Alosa pseudoharengus) in some acidic rivers of Nova Scotia

1985 ◽  
Vol 63 (10) ◽  
pp. 2254-2261 ◽  
Author(s):  
Gilles L. Lacroix
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Ovarian Development ◽  
Ionic Composition ◽  
Alosa Pseudoharengus ◽  
White Sucker ◽  
Hematocrit Level ◽  
Catostomus Commersoni ◽  
Atlantic Salmon Salmo Salar ◽  
Laboratory Models

Atlantic salmon (Salmo salar) smolts migrating from two acidic rivers (pH 4.9 and 5.2) had high hematocrit levels (> 50%) and low plasma [Cl−] (< 100mequiv. L−1). The hematocrit level was 10% higher and plasma [Na+] was 17% lower in smolts of the more acidic of the two rivers. Salmon parr in rivers of mean pH 5.0, 5.4, and 6.0 over a 7-month period had high hematocrit levels (> 40%) and low plasma [Cl−] (< 125 mequiv. L−1). Plasma [Na+] and [Cl] were both slightly less (~ 5%) and plasma [K+] was higher (> 1.5 times) in parr from the river of pH 5.0 than in those from the other two rivers. Atlantic salmon smolts were more sensitive to low pH (plasma [Na+] 14% less, [Cl] 17% less, and hematocrit level 37% higher) than parr, and parr of the 0+ age-class were more sensitive (plasma [Na+] 9% less) than 1+ parr. Prespawning white suckers (Catostomus commersoni) and alewives (Alosa pseudoharengus) migrating in a river at pH 4.9 had high hematocrit levels and low plasma [Cl−], and alewives (hematocrit, 66%; plasma [Cl], 65 mequiv. L−1) were more severely affected than suckers (hematocrit, 42%; plasma [Cl−], 91 mequiv. L−1). Plasma [Ca2+] in females of both species was not greatly elevated relative to males (female/male [Ca2+] = 1.21 in suckers and 1.14 in alewives), suggesting a possible impairment of calcium metabolism associated with ovarian development. The physiological effects observed in fish inhabiting soft waters (external [Ca2+] < 0.10 mequiv. L−1) at pH levels of about 5.0 generally correlated well with the laboratory "models" of acid exposure in soft water.

Sodium Balance in the Eggs of the Atlantic Salmon, Salmo Salar

1969 ◽  
Vol 50 (1) ◽  
pp. 239-246
Author(s):  
P. P. RUDY ◽  
W. T. W.POTTS
Keyword(s):  
Atlantic Salmon ◽  
Protein Content ◽  
Salmo Salar ◽  
Sodium Balance ◽  
Sodium Ions ◽  
Stages Of Development ◽  
Sodium Accumulation ◽  
Atlantic Salmon Salmo Salar ◽  
Perivitelline Fluid ◽  
Ambient Concentration

1. Exchanges of sodium ions between the egg of the salmon and the environment have been examined at different stages. 2. In freshly stripped eggs and during the early stages of development exchange is confined to the chorion and perivitelline fluid. 3. The perivitelline fluid can accumulate sodium to several times the ambient concentration probably by a Donnan effect associated with its protein content. At low external concentrations the relative accumulation is lower than the Donnan theory predicts. 4. Sodium accumulation begins during the eyed stage and accelerates after hatching.

Microstructure and texture of fresh and smoked Atlantic salmon, Salmo salar L., fillets from fish reared and slaughtered under different conditions

2001 ◽  
Vol 32 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Sjofn Sigurgisladottir ◽  
Margret S. Sigurdardottir ◽  
Helga Ingvarsdottir ◽  
Ole J. Torrissen ◽  
Hannes Hafsteinsson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar

Persistence of Orally Administered Salmonella enterica Serovars Agona and Montevideo in Atlantic Salmon (Salmo salar L.)

2005 ◽  
Vol 68 (7) ◽  
pp. 1336-1339 ◽  
Author(s):  
L. L. NESSE ◽  
T. LØVOLD ◽  
B. BERGSJØ ◽  
K. NORDBY ◽  
C. WALLACE ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Salmonella Enterica ◽  
Most Probable Number ◽  
Fish Feed ◽  
Internal Organs ◽  
Probable Number ◽  
Atlantic Salmon Salmo Salar ◽  
Gastric Intubation

The objective of our experiments was to study the persistence and dissemination of orally administered Salmonella in smoltified Atlantic salmon. In experiment 1, salmon kept at 15°C were fed for 1 week with feed contaminated with 96 most-probable-number units of Salmonella Agona per 100 g of feed and then starved for 2 weeks. Samples were taken from the gastrointestinal tract and examined for Salmonella 1, 2, 8, 9, 15, and 16 days after the feeding ended. In experiment 2, Salmonella Agona and Montevideo were separately mixed with feed and administered by gastric intubation. Each fish received 1.0 × 108, 1.0 × 106, or 1.0 × 104 CFU. The different groups were kept in parallel at 5 and 15°C and observed for 4 weeks. Every week, three fish in each group were sacrificed, and samples were taken from the skin, the pooled internal organs, the muscle, and the gastrointestinal tract and examined for the presence of Salmonella. The results from the two experiments showed that the persistence of Salmonella in the fish was highly dependent on the dose administered. Salmonella was not recovered from any of the fish that were fed for 1 week with the lowest concentration of Salmonella. In the fish given the highest dose of Salmonella, bacteria persisted for at least 4 weeks in the gastrointestinal tract as well as, to some extent, the internal organs. The present study shows that under practical conditions in Norway, the risk of Salmonella in fish feed being passed on to the consumer of the fish is negligible.

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