The role of growth hormone in the adaptability of Atlantic salmon (Salmo salar L.) to seawater: effects on the morphology of the mucosa of the middle intestine

1995 ◽  
Vol 73 (12) ◽  
pp. 2361-2374 ◽  
Author(s):  
L. Nonnotte ◽  
G. Boeuf ◽  
G. Nonnotte
Keyword(s):  
Growth Hormone ◽  
Basement Membrane ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
High Salinity ◽  
Basal Part ◽  
Intercellular Spaces ◽  
Sham Treatment ◽  
Treated Fish

Ultrastructural modifications of the middle intestine of the salmon, Salmo salar, induced by transfer to seawater have been studied in two groups of fish: the first group received sham treatment and the second was treated with ovine growth hormone (oGH). In sham-treated fish during the first 2 days in seawater, significant distension of the intercellular spaces was observed between the apical tight junction and the basement membrane. In the basal part of the enterocytes, tubular invaginations in the intercellular spaces were closely associated with mitochondria. In oGH-implanted fish, we observed no signs of modification of the ultrastructure of the mucosa. There were no dilatations of the intercellular spaces and no infoldings in the basal part of the enterocytes. After 7 days in seawater, the mucosa of the intestine of sham- and oGH-treated fish was quite similar. The effects of oGH treatment were clear, and treatment seemed to provoke "pre-adaptation" of the intestinal mucosa before exposure to high salinity to maintain the morphology of the middle intestine of Atlantic salmon abruptly transferred to seawater.

Evidence for the role of growth hormone as a part of a 'light–pituitary axis' in growth and smoltification of Atlantic salmon (Salmo salar)

1976 ◽  
Vol 54 (4) ◽  
pp. 544-551 ◽  
Author(s):  
M. P. Komourdjian ◽  
R. L. Saunders ◽  
J. C. Fenwick
Keyword(s):  
Growth Hormone ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
High Salinity ◽  
Separate Experiment ◽  
Pars Intermedia ◽  
Prolactin Cells ◽  
Atlantic Salmon Salmo Salar ◽  
Natural Photoperiod

Atlantic salmon (Salmo salar) parr were subjected to one of two photoperiod regimens: a simulated natural photoperiod, or a reciprocal photoperiod (with a light-to-dark ratio opposite to that of the natural photoperiod). The animals were held at 10 °C from mid-December onward and were sampled at 3-week intervals.By February, salmon held under the reciprocal photoperiod were significantly longer, had lower condition factors, and looked and behaved more like smolts than did those under the natural photoperiod. A separate experiment showed that salinity tolerance increased at this time. In June the situation was reversed; the salmon kept under the natural photoperiod showed greatest growth and high salinity tolerance.Longer days in either regimen coincided with an increase in number and apparent activity of pituitary somatotrops of the animals. Adrenocorticotropin (ACTH), pars intermedia, and prolactin cells were also judged to be active under these conditions. A role for growth hormone and other peptides as components of a 'light–pituitary axis' is discussed in relation to the parr–smolt transformation of Atlantic salmon.

The effect of porcine somatotropin on growth, and survival in seawater of Atlantic salmon (Salmo salar) parr

1976 ◽  
Vol 54 (4) ◽  
pp. 531-535 ◽  
Author(s):  
M. P. Komourdjian ◽  
R. L. Saunders ◽  
J. C. Fenwick
Keyword(s):  
Growth Hormone ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Growth Hormone Treatment ◽  
Hormone Treatment ◽  
Control Fish ◽  
Growth And Survival ◽  
Atlantic Salmon Salmo Salar ◽  
Porcine Somatotropin

The effects of porcine growth hormone on growth and salinity tolerance were studied in Atlantic salmon (Salmo salar) parr. Fish were held in freshwater at 11.5 °C during June and July under a photoperiod with light to dark periods opposite to the prevailing natural conditions. Fish treated with 1.0 μg/g body weight of growth hormone preparation on alternate days were significantly longer (P <.05), after 4 weeks, than placebo-injected controls. All hormone-injected fish survived transfer to seawater, 30‰ salinity. But under the same conditions, placebo-injected control fish showed a high mortality rate. Growth-hormone treatment caused a darkening of fin margins and a yellowing of the operculae and fin surfaces. The silvering which normally accompanies smoltification was not observed. The role of growth hormone in eliciting these actions and its possible role in the parr–smolt transformation are discussed.

Role of Fat Stores in the Maturation of Male Atlantic Salmon (Salmo salar) Parr

1991 ◽  
Vol 48 (3) ◽  
pp. 405-413 ◽  
Author(s):  
D. K. Rowe ◽  
J. E. Thorpe ◽  
A. M. Shanks
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Gonadosomatic Index ◽  
Total Lipids ◽  
Fat Accumulation ◽  
Atlantic Salmon Salmo Salar ◽  
Mesenteric Fat ◽  
Fat Stores

We provide evidence that in male Atlantic salmon (Salmo salar) parr, maturation is suppressed when mesenteric fat fails to exceed an undefined level by May. In nonmaturing parr the postwinter increase in total lipids began in May, while the mesenteric store started filling in June. However, in male parr which would have matured, total lipids started increasing a month earlier, in April, and the mesenteric store started filling in May. Consequently, maturing male parr had significantly more mesenteric fat than nonmaturing fish by June. Mesenteric fat is needed for maturation. Levels continued to increase in nonmaturing parr during autumn months, but had declined in maturing parr by September. This depletion of mesenteric fat in maturing males coincided with increases in the gonadosomatic index from 0.05 to 10% and with reductions in both feeding and growth. Fasting during spring months delayed increases in total lipids and fat accumulation into the mesenteric store until June and suppressed maturation rates of male parr. The internal decision to suppress maturation is therefore dependent on mesenteric fat levels increasing in May. However, this requires the prior replenishment of other stores in April. A model is proposed to explain the physiological link between fat accumulation during spring and the initiation of maturation.

Osmoregulation, feed intake, growth and growth hormone levels in 0+ Atlantic salmon (Salmo salar L.) transferred to seawater at different stages of smolt development

Aquaculture ◽  
2003 ◽  
Vol 222 (1-4) ◽  
pp. 167-187 ◽  
Author(s):  
Arne M. Arnesen ◽  
Hilde Toften ◽  
Thorleifur Agustsson ◽  
Sigurd O. Stefansson ◽  
Sigurd O. Handeland ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Feed Intake ◽  
Hormone Levels ◽  
Atlantic Salmon Salmo Salar
Sign in / Sign up

Export Citation Format

Share Document