Effects of water-borne 4-nonylphenol and 17β-estradiol exposures during parr-smolt transformation on growth and plasma IGF-I of Atlantic salmon (Salmo salar L.)

2004 ◽  
Vol 66 (3) ◽  
pp. 255-265 ◽  
Author(s):  
J.T.M Arsenault ◽  
W.L Fairchild ◽  
D.L MacLatchy ◽  
L Burridge ◽  
K Haya ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar ◽  
Igf I ◽  
17Β Estradiol ◽  
Water Borne

Changes in Plasma T4 and T3 Levels during Reconditioning and Rematuration in Male and Female Wild Atlantic Salmon (Salmo salar) Kelts Held in Freshwater under Two Photoperiod Regimes

1991 ◽  
Vol 48 (12) ◽  
pp. 2443-2448 ◽  
Author(s):  
J. G. Eales ◽  
D. G. Cyr ◽  
K. Finnson ◽  
C. E. Johnston
Keyword(s):  
Plasma Level ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Early Spring ◽  
Reproductive State ◽  
Male And Female ◽  
Atlantic Salmon Salmo Salar ◽  
17Β Estradiol ◽  
Males And Females ◽  
Low Levels

The plasma level of L-thyroxine (T4) of wild reconditioned Atlantic salmon (Salmo salar) kelts held in freshwater at seasonal temperatures on a natural simulated photoperiod showed a robust seasonal profile with a marked peak in early spring followed by low levels throughout the summer. Plasma T4 was low in kelts that did not recondition and was uninfluenced by gender, eventual reproductive state, or imposition of a 6-mo compressed photocycle. The plasma 3,5,3′-triiodo-L-thyronine (T3) level also rose in spring in both males and females. In males and nonreproducing females, plasma T3 remained high during the growth phase in summer and decreased in fall and winter. Plasma T3 was very low in nonfeeding fish and showed some influence by the 6-mo compressed photocycle. Plasma T3 was particularly low in females at the time of vitellogenesis when 17β-estradiol was high. It is concluded that in reconditioned Atlantic salmon kelts, levels of plasma T4 and T3 appear to be controlled independently and that plasma T3 is more susceptible than T4 to vitellogenic state and other factors relating to metabolic demands.

scholarly journals Growth hormone endocrinology of Atlantic salmon (Salmo salar): pituitary gene expression, hormone storage, secretion and plasma levels during parr-smolt transformation

2001 ◽  
Vol 170 (1) ◽  
pp. 227-234 ◽  
Author(s):  
T Agustsson ◽  
K Sundell ◽  
T Sakamoto ◽  
V Johansson ◽  
M Ando ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Mrna Expression ◽  
Salmo Salar ◽  
Plasma Levels ◽  
Secretion Rate ◽  
Gh Secretion ◽  
Atlantic Salmon Salmo Salar ◽  
Igf I ◽  
Plasma Gh

A number of studies on the Atlantic salmon (Salmo salar), have reported changes in plasma GH during parr-smolt transformation, but there is a lack of information about the endocrinology of the GH system during this process. In order to elucidate the mechanisms underlying these changes in plasma GH levels during the parr-smolt transformation of Atlantic salmon, GH mRNA expression in the pituitary was studied together with total pituitary GH content, in vitro GH secretion rate and plasma GH and IGF-I levels. Atlantic salmon were kept in outside tanks, under natural condition from early February until late June. Approximately three times a month fish were killed and pituitaries and blood were sampled for investigation. Further, pituitaries were moved to the laboratory for in vitro GH secretion studies. The results show that the GH system is first activated by an increase in GH secretion rate, which leads to an increase in plasma GH levels and causes a drop in the total GH content of the pituitary. This drop in pituitary GH content is later reversed by an increased GH synthesis seen as an increase in GH mRNA expression. Maximal activation of the GH system is seen to occur in early May, when plasma IGF-I levels reach highest levels, after which a certain deactivation of the GH system takes place. The data show that plasma levels of GH are to a large extent regulated by the secretion rate from the pituitary, although changes in the GH clearance rate are also likely to take place and influence the plasma GH levels. The study further underlines the significant role that the GH-IGF-I axis plays in the parr-smolt transformation of the Atlantic salmon.

Effects of domestication on growth physiology and endocrinology of Atlantic salmon (Salmo salar)

2002 ◽  
Vol 59 (8) ◽  
pp. 1323-1330 ◽  
Author(s):  
Ian A Fleming ◽  
Thorleifur Agustsson ◽  
Bengt Finstad ◽  
Jörgen I Johnsson ◽  
Björn Thrandur Björnsson
Keyword(s):  
Growth Rate ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Growth Regulation ◽  
Salt Water ◽  
Endocrine Regulation ◽  
Founder Population ◽  
Growth Physiology ◽  
Atlantic Salmon Salmo Salar ◽  
Igf I

Selection programs for fish frequently target growth rate as a breeding goal, yet surprisingly little is known about which mechanisms underlying the growth process are being targeted. The aim of this study was thus to examine whether the process of artificial selection of Atlantic salmon (Salmo salar) that has resulted in higher growth rate resulted in underlying changes in the growth hormone (GH) – insulin-like growth factor I (IGF-I) axis of endocrine growth regulation. This was tested by comparing similarly reared seventh-generation farm salmon with wild salmon from the principal founder population of the farm strain at three life stages. Not unexpectedly, the domesticated fish outgrew their wild counterparts; this was most evident in salt water, where they averaged three times the weight by the end. Pituitary GH content was positively correlated with growth rate and correspondingly was significantly higher in the faster growing domesticated fish than in the wild fish. Plasma GH levels were also significantly higher in the domesticated fish, whereas IGF-I levels did not differ. These findings provide some of the first direct evidence indicating a link between domestication selection for growth and its endocrine regulation, whereby individuals with more active endocrine growth regulatory components are targeted.

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
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