Androgens impair seawater adaptability in smolting Baltic salmon (Salmo salar)

1989 ◽  
Vol 67 (7) ◽  
pp. 1733-1736 ◽  
Author(s):  
H. Lundqvist ◽  
B. Borg ◽  
I. Berglund
Keyword(s):  
Salmo Salar ◽  
Challenge Test ◽  
Fork Length ◽  
Temporal Organization ◽  
Control Fish ◽  
Plasma Sodium ◽  
High Sodium ◽  
Negative Effect ◽  
Mature Fish ◽  
Seawater Challenge

Sexually immature (females and males) and mature male two-summer-old Baltic salmon (Salmo salar) were implanted with silastic capsules containing testosterone or 11-ketoandrostenedione in spring before the smoltification period. The seawater adaptability of the hormone-treated fish and intact control fish or control fish implanted with empty capsules was tested periodically from May to July using a common seawater challenge test with 25‰ saltwater. Fish were selected from the Norrfors hatchery stock (Ume River, (63°50′N, 20°05′E)) and ranged in fork length from 13 to 17 cm. At all sampling times the immature control fish displayed a better seawater adaptability than the previously mature males. Both groups exhibited a seasonal smoltification pattern with maximal adaptability in mid-June, when the mean plasma sodium levels after challenge were 161 mmol in the immature and 193 mmol in the mature fish. At all times both androgens impaired the seawater adaptability of the immature fish, which displayed high sodium levels comparable to those in untreated previously mature males. Even higher sodium levels were reached in previously mature males treated with androgen capsules. However, in all categories of fish the lowest levels of plasma sodium were found at the same time in mid-June. This indicates that although there is a marked, negative effect of sexual maturation and androgens on seawater adaptability, the temporal organization of smoltification is not affected.

Seawater adaptability in Baltic salmon, Salmo salar, immature smolt and mature male parr: lack of effect of springtime castration

1990 ◽  
Vol 68 (10) ◽  
pp. 2181-2184 ◽  
Author(s):  
Hans Lundqvist ◽  
Ingemar Berglund ◽  
Ian Mayer ◽  
Bertil Borg
Keyword(s):  
Salmo Salar ◽  
Sexual Maturation ◽  
Early Summer ◽  
Mature Male ◽  
Plasma Sodium ◽  
Sham Operation ◽  
Challenge Tests ◽  
Seawater Challenge ◽  
Mature Male Parr ◽  
Immature Fish

Seawater adaptability was tested in different categories of 2-year-old Baltic salmon from the Ume River stock over the smoltification period in late spring – early summer by means of seawater challenge tests. Previously mature male parr and immature fish adapted equally well in early to mid May, whereas in later May and June the previously mature males displayed much higher plasma sodium levels after challenge than the immature fish. Neither castration nor sham operation of previously mature males in March led to decreases in plasma sodium levels following seawater challenges in June. In addition, sham-operated immature females were not affected. The results indicate that sexual maturation exerts an effect on osmoregulation that prevails long after the androgen source has disappeared.

Effects of a temperature shift on seawater challenge test performance in Atlantic salmon (Salmo salar) smolt

Aquaculture ◽  
2001 ◽  
Vol 201 (1-2) ◽  
pp. 153-159 ◽  
Author(s):  
Magne Staurnes ◽  
Trygve Sigholt ◽  
Torbjørn Åsgård ◽  
Grete Baeverfjord
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Test Performance ◽  
Challenge Test ◽  
Temperature Shift ◽  
Atlantic Salmon Salmo Salar ◽  
Seawater Challenge

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.

Annual Variations in Rheotactic Behaviour and Seawater Adaptability in Landlocked Arctic Char (Salvelinus alpinus)

1992 ◽  
Vol 49 (3) ◽  
pp. 448-452 ◽  
Author(s):  
Monika Schmitz
Keyword(s):  
Seasonal Changes ◽  
Salvelinus Alpinus ◽  
Challenge Test ◽  
Early Summer ◽  
Rapid Decrease ◽  
Arctic Char ◽  
Migratory Behaviour ◽  
Annual Variations ◽  
Seawater Tolerance ◽  
Seawater Challenge

The existence of basic smoltification characteristics, measured by means of seasonal changes in rheotactic behaviour and seawater adaptability, was studied from February to November in 1- and 2-yr-old landlocked Arctic char (Salvelinus alpinus). Up- and downstream directed movements were monitored in an annular stream tank at a water velocity of 0.2 m/s. A 48-h seawater challenge test using 25‰ seawater was performed at monthly intervals throughout the year to assess seawater adaptability. The 1-yr-old char displayed mainly nondirectional behaviour during spring, but from August onwards the movements were predominantly against the current. Seawater performance improved slightly in this group in May and June. The 2-yr-old char progressively developed a downstream behaviour and exhibited an increased seawater adaptability during spring and early summer. In late August, a marked reversal in rheotactic behaviour occurred, followed by a rapid decrease in seawater tolerance. The results demonstrate that seasonal changes in seawater adaptability and changes in migratory behaviour which were directionally consistent with smolting still exist in a population of Arctic char that has been landlocked for about 6000 yr.

Variation in Male Parr Maturation Within and Among Populations of Atlantic Salmon, Salmo salar

1986 ◽  
Vol 43 (6) ◽  
pp. 1242-1248 ◽  
Author(s):  
Ransom A. Myers ◽  
Jeffrey A. Hutchings ◽  
R. John Gibson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Fork Length ◽  
Detectable Effect ◽  
Genetic Changes ◽  
Mature Parr ◽  
Total Proportion ◽  
Second Year ◽  
Size Threshold ◽  
Atlantic Salmon Parr

The covariation of growth and maturation in male Atlantic salmon parr, Salmo salar, produces a relationship characterized by a size threshold below which individuals generally do not mature. The threshold of 70–72 mm fork length is evident both within and among populations. Parr maturation can reduce growth during the second year of life by an average of 4.0%. Among-year variation in growth rate affects the yearly incidence of maturation for males at age 1 + but has no detectable effect on the total proportion of male parr maturing in a population. Increases in the proportion of mature parr in the Matamek River, Quebec, can be explained by variation in growth alone; there is no evidence for genetic changes in this population.

scholarly journals Pengaruh Suplementasi Probiotik A3-51 terhadap Derajat Imunitas Oreochromis niloticus Didasarkan pada Angka Kuman pada Ginjal Setelah Uji Tantang dengan Aeromonas hydrophila dan Aeromonas salmonicida achromogenes

2006 ◽  
Vol 8 (2) ◽  
pp. 144
Author(s):  
Agus Irianto ◽  
Hernayanti Hernayanti ◽  
Ning Iriyanti
Keyword(s):  
Aeromonas Hydrophila ◽  
Oreochromis Niloticus ◽  
Challenge Test ◽  
Aeromonas Salmonicida ◽  
Control Fish ◽  
System Response ◽  
Randomized Design ◽  
Immune System Response ◽  
Completely Randomized Design ◽  
Number Of Bacteria

Objectives of this research was to know the effect of probiotic A3-51 supplementation on food to the total number of bacteria in kidney and mortality of Oreochromis niloticus after challenge test with Aeromonas hydrophila and Aeromonas salmonicida achromogenes. This research was consisted of two experiment, the first was to know the highest immunity level of fish based on the number of macrophage and its phagocytic activity. Meanwhile, the second was to know the immunity level of fish challenged with A. hydrophila and A. salmonicida achromogenes by intra-peritoneal injection. The experiment used Completely Randomized Design in triplicates. The result from the first experiment showed that the highest non spesific immune system response, by means number of macrophage, was found 21 days treatment. The second experiment showed that the highest total number of bacteria in kidney and mortality level were 20.23 x 108 cells/g and 46.67%, respectively, both was found in control fish injected intra-peritoneally with A. salmonicida achromogenes.

Effects of Diet or Liming on Steroid Hormone Metabolism and Reproduction in Atlantic Salmon (Salmo salar) Held in an Acidic River

1990 ◽  
Vol 47 (12) ◽  
pp. 2422-2430 ◽  
Author(s):  
G. B. Sangalang ◽  
H. C. Freeman ◽  
J. F. Uthe ◽  
L. S. Sperry
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Reproductive Performance ◽  
Steroid Hormone ◽  
Control Fish ◽  
Dietary Salt ◽  
Hormone Metabolism ◽  
Atlantic Salmon Salmo Salar ◽  
Water Ph ◽  
Acidic River

Attempts to avert the impacts of an acidic river environment on Atlantic salmon (Salmo salar) were carried out in 1985 and 1986. Salmon were held in the Westfield River (pH 4.7–5.2) and the nearby Medway River (pH 5.3–5.6) during their sexual maturation. A diet containing 3% NaCl was fed to the Westfield salmon in 1985. Marble chips were used to elevate the pH of Westfield River water in 1986. Fish fed the salt diet had higher peak levels of plasma sex hormones, higher fecundity, greater incidence of spawners, lower egg mortality, and less weight loss than fish fed a commercial trout diet. The reproductive performance of fish held in limed water (pH 5.1–5.9) almost attained the level observed in the Medway (control) fish. Limestone treatment stimulated early peaking of blood androgen levels, testosterone, and 11-ketotestosterone in Westfield males, and 17α, 20β-dihydroxy-4-pregnen-3-one, a follicular mediator of gonadotropin, in a few Westfield females. The head kidneys produced more cortisol and corticosterone in all Westfield fish in both years compared to Medway fish. The results suggest that neither dietary salt nor liming completely prevented the decline of reproductive performance and the alteration of steroid hormone metabolism in salmon.

Effect of Photoperiods on the Reactions of Juvenile Atlantic Salmon (Salmo salar L.) to Light Stimuli

1963 ◽  
Vol 20 (5) ◽  
pp. 1245-1266 ◽  
Author(s):  
A. T. Pinhorn ◽  
C. W. Andrews
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Light Stimulus ◽  
Continuous Light ◽  
Control Fish ◽  
Intermittent Light ◽  
Exposed Fish ◽  
Juvenile Atlantic Salmon ◽  
Light Stimuli ◽  
Increased Activity

The reactions to light stimuli of juvenile Atlantic salmon exposed to photoperiods (light-exposed fish) and those exposed to control conditions (control fish) were compared. The light-exposed fish showed more activity and reacted more readily to stimuli than the control fish. Both the control and light-exposed fish exhibited a negative phototaxis at all light intensities except the very lowest where a slight positive phototaxis was obvious. The intensity of an intermittent light stimulus had very little effect on the intensity of the reaction in the light-exposed fish, while the control fish showed an increase in the intensity of the reaction with an increase in the intensity of the light stimulus. The control fish showed an increase in the reaction to the intermittent light stimulus the longer the stimulus was applied at the higher levels of stimulation, while the light-exposed fish showed this behavior at the lower levels of stimulation. The reactions to continuous light were similar to the reactions to intermittent light stimuli, but the light-exposed fish reacted more quickly to continuous light than the control fish. These differences in behavior are attributed to the increased activity and sensitivity of the light-exposed fish, resulting from their exposure to photoperiods.

High-sodium intake prevents pregnancy-induced decrease of blood pressure in the rat

2003 ◽  
Vol 285 (1) ◽  
pp. H375-H383 ◽  
Author(s):  
Annie Beauséjour ◽  
Karine Auger ◽  
Jean St-Louis ◽  
Michèle Brochu
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Sodium Intake ◽  
Plasma Sodium ◽  
Mrna Levels ◽  
Sprague Dawley ◽  
Pregnant Rats ◽  
High Sodium ◽  
High Sodium Intake ◽  
The Impact

Despite an increase of circulatory volume and of renin-angiotensin-aldosterone system (RAAS) activity, pregnancy is paradoxically accompanied by a decrease in blood pressure. We have reported that the decrease in blood pressure was maintained in pregnant rats despite overactivation of RAAS following reduction in sodium intake. The purpose of this study was to evaluate the impact of the opposite condition, e.g., decreased activation of RAAS during pregnancy in the rat. To do so, 0.9% or 1.8% NaCl in drinking water was given to nonpregnant and pregnant Sprague-Dawley rats for 7 days (last week of gestation). Increased sodium intakes (between 10- and 20-fold) produced reduction of plasma renin activity and aldosterone in both nonpregnant and pregnant rats. Systolic blood pressure was not affected in nonpregnant rats. However, in pregnant rats, 0.9% sodium supplement prevented the decreased blood pressure. Moreover, an increase of systolic blood pressure was obtained in pregnant rats receiving 1.8% NaCl. The 0.9% sodium supplement did not affect plasma and fetal parameters. However, 1.8% NaCl supplement has larger effects during gestation as shown by increased plasma sodium concentration, hematocrit level, negative water balance, proteinuria, and intrauterine growth restriction. With both sodium supplements, decreased AT1 mRNA levels in the kidney and in the placenta were observed. Our results showed that a high-sodium intake prevents the pregnancy-induced decrease of blood pressure in rats. Nonpregnant rats were able to maintain homeostasis but not the pregnant ones in response to sodium load. Furthermore, pregnant rats on a high-sodium intake (1.8% NaCl) showed some physiological responses that resemble manifestations observed in preeclampsia.

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