Acclimation to seawater of dwarf nonanadromous Atlantic salmon, Salmo salar

1993 ◽  
Vol 71 (9) ◽  
pp. 1912-1916 ◽  
Author(s):  
Tim P. Birt ◽  
John M. Green
Keyword(s):  
Enzyme Activity ◽  
Atlantic Salmon ◽  
Fresh Water ◽  
Salmo Salar ◽  
Chloride Cell ◽  
Chloride Cells ◽  
Activity Levels ◽  
Ion Concentrations ◽  
External Salinity ◽  
Hydromineral Balance

The ability of nonanadromous Atlantic salmon to regulate hydromineral balance in seawater was assessed by determining plasma Na+ and Cl− concentrations, gill Na+–K+ ATPase activity levels, and gill chloride-cell length in fish exposed to gradually increasing salinity. Plasma ion levels were much higher in nonanadromous salmon exposed to seawater than in anadromous smolts in the same condition, and in both forms held in fresh water. This indicates a lower level of hypoosmoregulatory ability in the nonanadromous form. The activity of gill Na+–K+ ATPase was low in nonanadromous salmon at the beginning of the experiment but increased in response to elevated external salinity. Mortality approached 100% despite increased enzyme activity levels. Salmon retained in fresh water did not exhibit increased enzyme activity. Anadromous smolts exposed to the same conditions exhibited somewhat elevated yet nonlethal plasma ion concentrations. Gill chloride cells increased in size in salmon exposed to seawater and decreased in size in fish held in fresh water. Hypoosmoregulatory inability and a general suppression of the smolting process in some stocks of nonanadromous salmon may be associated with sexual maturation at a young age. However, this is not universal, since nonanadromous salmon in some other stocks mature later yet show clear evidence of reduced smolting.

Influence of Photoperiod on the Number and Ultrastructure of Gill Chloride Cells of the Atlantic Salmon (Salmo salar) before and during Smoltification

1991 ◽  
Vol 48 (7) ◽  
pp. 1302-1307 ◽  
Author(s):  
Robert T. Lubin ◽  
A. W. Rourke ◽  
Richard L. Saunders
Keyword(s):  
Atlantic Salmon ◽  
Atpase Activity ◽  
Salmo Salar ◽  
Chloride Cell ◽  
Constant Light ◽  
Chloride Cells ◽  
Cell Numbers ◽  
Atlantic Salmon Salmo Salar ◽  
Threefold Increase ◽  
Natural Photoperiod

Atlantic salmon (Salmo salar) larger than 9 cm held under constant light since October had greater numbers of gill chloride cells in February compared with fish held under simulated natural photoperiod. By April, fish raised under simulated natural photoperiod were able to survive salinity tests, had a threefold increase in Na+/K+ ATPase activity, and had increased chloride cell numbers. These increases and salinity tolerance did not occur in fish raised under constant light. Only fish reared under constant light developed apical pits with large and numerous microvilli.

The effects of transecting the IXth and Xth cranial nerves on hydromineral balance in the eel Anguilla anguilla

1976 ◽  
Vol 64 (2) ◽  
pp. 461-475
Author(s):  
N. Mayer-Gostan ◽  
T. Hirano
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Cranial Nerves ◽  
Anguilla Anguilla ◽  
Vagus Nerves ◽  
Rapid Reduction ◽  
Ion Concentrations ◽  
Excess Loss ◽  
Na Efflux ◽  
Hydromineral Balance

The IXth and the Xth cranial nerves in Anguilla anguilla were transected, and the effects upon ion and water balance were studied in fresh water and sea water, and during transfer from fresh water and vice versa. In fresh water there is a slow demineralization due to an excess loss of Na and Cl ions. During freshwater to seawater transfer the eel survives only for 4–5 days. The fish do not drink and Na efflux does not increase enough to extrude excess ions. In sea water the glossopharyngeal and vagus nerves are necessary for the maintenance of the hydromineral balance. Denervation is followed by an increase in plasma ion concentrations. Na fluxes are not modified and increased water loss is not compensated by drinking. The rapid reduction of Na efflux during transfer from sea water to fresh water is not modified by denervation.

scholarly journals Comparison of the Fatty Acid and Triglyceride Profiles of Big Eye Tuna (Thunnus obesus), Atlantic salmon (Salmo salar) and Bighead Carp (Aristichthysnobilis) Heads

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3983 ◽  
Author(s):  
Jing Zhang ◽  
Ningping Tao ◽  
Yueliang Zhao ◽  
Xichang Wang ◽  
Mingfu Wang
Keyword(s):  
Fatty Acid ◽  
Atlantic Salmon ◽  
Fresh Water ◽  
Salmo Salar ◽  
Bighead Carp ◽  
Fresh Water Fish ◽  
Atlantic Salmon Salmo Salar ◽  
Thunnus Obesus ◽  
Significant Difference ◽  
Latent Structures

Big eye tuna (Thunnus obesus), Atlantic salmon (Salmo salar) and bighead carp (Aristichthys nobilis) are three representative marine and fresh water fishes. In this study, the content of total lipids (TL), triglyceride (TG) fraction, and the fatty acid profiles in the corresponding fish heads were analyzed. Meanwhile, their complicated TG molecular species were further characterized. The results showed that TG was the major lipid in these three fish heads (60.58–86.69%). Compared with other two fish heads, big eye tuna head was the most abundant in polyunsaturated fatty acids, among which eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) accounted for 64.29% and 32.77% in the TL and TG fraction, respectively. It is also worth noting that EPA+DHA/total fatty acid (TFA) value of TL and TG fraction from bighead carp head showed no significant difference with Atlantic salmon head, a typical marine fish. There were 146 TG molecules detected in big eye tuna head, 90 in Atlantic salmon and 87 in bighead carp heads. DHA or EPA accounted for 56.12%, 22.88%, and 5.46% of the total TG molecules in these three fish heads, respectively. According to principal component analysis, orthogonal projection to latent structures-discriminant analysis and the constructed heat map, the three samples could be completely differentiated based on their TG molecule fingerprints. This study is the first to compare marine and fresh water fish from the perspective of their heads’ fatty acid and TG molecule profiles.

scholarly journals Effects of growth hormone on gill chloride cells in juvenile Atlantic salmon (Salmo salar)

1994 ◽  
Vol 266 (3) ◽  
pp. R850-R857 ◽  
Author(s):  
P. Prunet ◽  
M. Pisam ◽  
J. P. Claireaux ◽  
G. Boeuf ◽  
A. Rambourg
Keyword(s):  
Growth Hormone ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Cell Types ◽  
Chloride Cells ◽  
Alpha Cells ◽  
Gh Treatment ◽  
Sodium Efflux ◽  
Atlantic Salmon Salmo Salar ◽  
Accessory Cells

Experiments were performed to investigate the effects of ovine growth hormone (oGH) on both the ultrastructural features of chloride cells and the ability of gills to extrude Na+ after transfer into seawater. February presmolts and June parrs of the Atlantic salmon (Salmo salar) were implanted with oGH. In such animals, spontaneously showing a poor ability to adapt themselves to seawater life, GH significantly increased gill Na(+)-K(+)-adenosinetriphosphatase activity as well as gill sodium efflux into seawater. When examined by electron microscope, two types of chloride cells (alpha- and beta-types) were identified in control parrs and presmolts. GH treatment induced an increase in size and number of alpha-cells that displayed an extensive tubular system, while the beta-cells, thought to be specific to freshwater life, decreased in number. There was, concomitantly, an increase in number of accessory cells associated with the apical portion of the alpha-cells and, as a result, the formation of extensive shallow junctions between these cell types. Such functional and ultrastructural modifications that mimicked those naturally occurring during the last steps of the smoltification strongly suggest that GH stimulates the differentiation of freshwater chloride cells toward a seawater type.

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