Influence of Photoperiod on Smolt Development and Growth of Atlantic Salmon (Salmo solar)

1970 ◽  
Vol 27 (7) ◽  
pp. 1295-1311 ◽  
Author(s):  
Richard L. Saunders ◽  
Eugene B. Henderson
Keyword(s):  
Atlantic Salmon ◽  
Sea Water ◽  
Endocrine System ◽  
Growth Patterns ◽  
Day Length ◽  
Thyroid Activity ◽  
Thyroid Glands ◽  
Before And After ◽  
Natural Photoperiod ◽  
External Stimuli

Atlantic salmon (Salmo salar) subjected in the spring to a constant photoperiod of 13 hr light/day or to simulated natural photoperiod (increasing day length) smoltified and grew rapidly before and after entering sea water. Others subjected to the reciprocal (complement) of natural photoperiod (decreasing day length in the spring) had the silvery color of smolts and grew rapidly but, unlike smolts, developed high condition factors while in fresh water. After they were transferred to sea water these fish ate less, grew more slowly, and had lower efficiencies of food conversion than those subjected to natural and constant photoperiod.Salmon experiencing reciprocal photoperiod had decreased sensitivity to external stimuli, suggesting reduced thyroid activity. Histological studies in June showed no differences in the appearance of the thyroid glands, suggesting no difference in thyroid activity between groups in natural and reciprocal photoperiod. Nor was there any difference in plasma osmotic and chloride levels between natural and reciprocal photoperiod groups, either in routinely active or fatigued fish.It is suggested that photoperiod acts through the endocrine system to affect growth patterns during and after smoking and possibly certain aspects of the smolting process itself. Effects of photoperiod on smolting and growth of salmon are discussed in connection with other cyclical changes in salmonid physiology known to be influenced by photoperiod.

Salinity Preference, Thyroid Activity and the Seaward Migration of Four Species of Pacific Salmon (Oncorhynchus)

1960 ◽  
Vol 17 (3) ◽  
pp. 295-322 ◽  
Author(s):  
Bertha Baggerman
Keyword(s):  
Fresh Water ◽  
Sockeye Salmon ◽  
Pacific Salmon ◽  
Salt Water ◽  
Iodine Content ◽  
Day Length ◽  
Thyroid Activity ◽  
Seaward Migration ◽  
Salinity Preference ◽  
External Stimuli

In juvenile Pacific salmon the changes in salinity preference associated with seaward migration and thyroid activity were studied and used as criteria for the induction of the physiological condition required for migration (migration-disposition).Four species of Oncorhynchus (chum, pink, coho and sockeye) changed preference from fresh to salt water at the onset of seaward migration and maintained this preference throughout the migration season. At the end of this migration period coho and sockeye salmon changed preference from salt to fresh water if retained in fresh water, indicating a re-adaptation to this medium in which they may survive for several years. Chum and pink fry did not show this change in preference and usually died when retained in fresh water. They were apparently unable to re-adapt to this environment.The increasing day length in spring controls the time at which the change in preference from fresh to salt water takes place, and is thus involved in timing the induction of migration-disposition.The photoperiod seems to affect particularly the pituitary-thyroid system. Thyroid activity increases shortly before the onset of migration, remains high during the migration season, and decreases towards its end. The level of thyroid hormone in the blood influences salinity tolerance and preference and, thus, the induction of migration-disposition. Metamorphosis, osmotic "stress" and iodine content of the water may have some additional effect on thyroid activity, but are not the only factors responsible for thyroid hyperactivity during migration.Animals in which migration-disposition has been induced are thought to have become susceptible to appropriate external stimuli "releasing" migration.

Endocrine-mediated photostimulation of growth in Atlantic salmon

1989 ◽  
Vol 67 (6) ◽  
pp. 1505-1509 ◽  
Author(s):  
M. P. Komourdjian ◽  
J. C. Fenwick ◽  
R. L. Saunders
Keyword(s):  
Phase Shift ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Growth Rates ◽  
Cell Types ◽  
Growth Cycle ◽  
Day Length ◽  
Atlantic Salmon Salmo Salar ◽  
Natural Photoperiod ◽  
Photoperiod Manipulation

The response of the Atlantic salmon (Salmo salar) pituitary to photoperiod manipulation was investigated histologically, and the observations were related to gross morphometric changes. Salmon were placed under either a simulated natural photoperiod (NP), a photoperiod complementary to the natural photoperiod (RP) or constant daylight (CL) in December. The latter two regimens stimulated the pituitary, particularly the somatotrops, and enhanced growth. After 6 weeks, the CL fish were longer than all others (P < 0.01) and their pituitaries showed marked hypertrophy, with many somatotrops and other cell types in mitosis. The RP fish were also longer (P < 0.01) than the NP animals at that time but their pituitaries appeared less stimulated than those of CL fish. However, the stimulation in CL and RP fish was not maintained beyond 3 months. At that time NP pituitaries more closely resembled the stimulated condition shown earlier by the RP glands. Our results confirm that changes in day length elicit corresponding changes in pituitary cytology and growth rates, albeit without eliminating an apparently innate growth cycle. While increased day length in winter may stimulate the pituitary, such regimens appear to render the gland refractory and cause a phase-shift in the rhythm. It is proposed that suitable interruptions in photostimulation may prolong stimulation.

Effect of a Reciprocal Photoperiod Regime on Standard Rate of Oxygen Consumption of Postsmolt Atlantic Salmon (Salmo salar)

1973 ◽  
Vol 30 (12) ◽  
pp. 1898-1900 ◽  
Author(s):  
Kathryn G. Withey ◽  
Richard L. Saunders
Keyword(s):  
Oxygen Consumption ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Sea Water ◽  
Late Summer ◽  
Atlantic Salmon Salmo Salar ◽  
Photoperiod Regime ◽  
Natural Photoperiod ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate

Postsmolt Atlantic salmon (Salmo salar) subjected to a reciprocal photoperiod regime (decreasing daylength from early March and increasing daylength from late June) had significantly lower standard rates of oxygen consumption than those subjected to a simulated natural photoperiod regime when both were tested in total darkness in sea water in late summer. A reduced metabolic level, as indicated by the low standard rate of oxygen consumption, in the test fish is consistent with earlier observations of reduced feeding and growth rates and food conversion efficiencies in similarly treated fish following transfer to sea water.

INFLUENCE OF PHOTOPERIOD ON THYROTROPIN RELEASING HORMONE-INDUCED PROLACTIN RELEASE IN EWES

1983 ◽  
Vol 63 (1) ◽  
pp. 67-73 ◽  
Author(s):  
B. E. HOWLAND ◽  
D. SONYA ◽  
L. M. SANFORD ◽  
W. M. PALMER
Keyword(s):  
Thyrotropin Releasing Hormone ◽  
Day Length ◽  
Constant Light ◽  
Serum Prolactin ◽  
Prolactin Release ◽  
Blood Samples ◽  
Releasing Hormone ◽  
Before And After ◽  
Release Curve ◽  
Short Days

The influence of photoperiod on serum prolactin levels and prolactin release induced by thyrotropin releasing hormone (TRH) was determined in ewes maintained under the following lighting regimes: Room 1, lighting mimicked natural changes in photoperiod; Room 2, annual photoperiod changes condensed into 6 mo with short days in June; Room 3, same as Room 2 except photoperiod changed abruptly from 16.5 to 8.0 h on 21 Mar. and back to 16.5 h on 21 June; Room 4, constant light. Weekly blood samples were obtained from February to August. Additionally, blood samples were collected before and after treatment with 10 μg TRH on 19 May, 13 June, 27 June and 19 July. Prolactin levels were elevated in ewes exposed to long days or constant light. The mean of all pre-TRH samples was significantly correlated with stress-induced elevations in prolactin (highest pre-TRH value) (r = 0.72) and area under the TRH-induced release curve (r = 0.56). The prolactin release in response to TRH was greatest in ewes exposed to long days or constant light. Abrupt increase of day length elevated pretreatment prolactin levels (P < 0.01) and increased area under the response curve (P < 0.05). Key words: Photoperiod, TRH, prolactin, ewes

Nutritive value of partially dehulled and extruded sunflower meal for post-smolt Atlantic salmon (Salmo salar L.) in sea water

2006 ◽  
Vol 37 (13) ◽  
pp. 1348-1359 ◽  
Author(s):  
Navneet Gill ◽  
David A Higgs ◽  
Brent J Skura ◽  
Mahmoud Rowshandeli ◽  
Bakhshish S Dosanjh ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Nutritive Value ◽  
Sea Water ◽  
Sunflower Meal ◽  
Atlantic Salmon Salmo Salar

TEMPERATURE RESISTANCE OF GOLDFISH MAINTAINED UNDER CONTROLLED PHOTOPERIODS

1959 ◽  
Vol 37 (4) ◽  
pp. 419-428 ◽  
Author(s):  
William S. Hoar ◽  
G. Beth Robertson
Keyword(s):  
Temperature Change ◽  
Seasonal Variations ◽  
Rapid Growth ◽  
Endocrine System ◽  
Early Spring ◽  
Late Winter ◽  
Thyroid Activity ◽  
Temperature Resistance ◽  
Sudden Temperature Change

Goldfish maintained under controlled photoperiods for 6 weeks or longer were relatively more resistant to a sudden elevation in temperature when the daily photoperiods had been long (16 hours) and relatively more resistant to sudden chilling when they had been short (8 hours). The magnitude of the effect varied with the season. Thyroid activity was slightly greater in fish maintained under the shorter photoperiods. The longer photoperiods stimulated more rapid growth of ovaries during late winter and early spring. The endocrine system is considered a link in the chain of events regulating seasonal variations in resistance to sudden temperature change.

Renal Osteodystrophy in Children with Chronic Renal Failure: An Unexpectedly Common and Incapacitating Complication

PEDIATRICS ◽  
1982 ◽  
Vol 70 (5) ◽  
pp. 742-750 ◽  
Author(s):  
Anthony C. Hsu ◽  
Sang Whay Kooh ◽  
Donald Fraser ◽  
William A. Cumming ◽  
Victor L. Fornasier
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Renal Osteodystrophy ◽  
Age At Onset ◽  
Growth Zone ◽  
Growth Patterns ◽  
Bone Lesions ◽  
Older Children ◽  
Before And After ◽  
End Stage

The incidence, age at onset, and progression of the biochemical, radiographic, and histologic characteristics of renal osteodystrophy were studied in 50 children in whom chronic renal failure had been recently diagnosed. During a ten-year observation period, 19 patients progressed to end-stage renal failure and radiographic signs of renal osteodystrophy developed in 15 of these (79%). Renal osteodystrophy developed in all nine patients whose chronic renal failure was diagnosed before 3 years of age and in six of the ten children with later onset of failure. The mean interval from diagnosis of renal failure to development of osteodystrophy was 1.4 years. Radiographically, growth zone lesions predominated in the younger children, whereas cortical erosions were more prevalent in the older children. Histologic examination, performed in 38 patients, showed both defective mineralization and excessive resorption and was a more sensitive diagnostic index than radiography. Noticeable deformities developed in one third of the patients with osteodystrophy, despite medical treatment including vitamin D2 therapy. Deformities were particularly frequent and Severe in patients whose renal failure developed in infancy. In all 13 patients whose growth patterns were studied before and after osteodystrophy developed, the onset of bone lesions was associated with a deterioration of growth, indicating that osteodystrophy plays a major role in causing the growth retardation commonly observed in children with chronic renal failure.

scholarly journals APLIKASI MINYAK CENGKEH SEBAGAI OBAT BIUS PADA KAKAP PUTIH (Lates calcarifer Bloch)

2006 ◽  
Vol 8 (1) ◽  
pp. 9
Author(s):  
Bambang Hanggono
Keyword(s):  
Survival Rate ◽  
Potential Application ◽  
Sea Water ◽  
Sea Bass ◽  
Abnormal Behavior ◽  
Clove Oil ◽  
Lates Calcarifer ◽  
Plastic Bag ◽  
Slope Function ◽  
External Stimuli

The objective of this study was to determine the safety and efficacy of clove oil as an anesthetic in sea bass (Lates calcarifer) and the potential application of clove oil as anesthetic to facilitate the sea bass fry transportation. Acute toxicity test indicated the 24-hr LC50 value of clove oil in sea bass fry as 30 ppm with slope function of 1.079 (1.05 to 1.107). In efficacy test, fish were exposed to 5, 10, 15, 20 and 25 ppm of clove oil for 15 minutes. At 5 ppm, clove oil caused only sedation effect (partial loss of reaction to external stimuli) while at 20 ppm, fish entered anesthesia stage (failure to respond to external stimuli) within about 3 minutes. Fish recovered from a 15-min period of exposure in 20 ppm clove oil within less than 10 minutes following removal from the anesthetic solution. There was neither mortality nor abnormal behavior of fish during 15-min exposure of clove oil as well as during 7 days post recovery from anesthesia. The potential application of clove oil as an aid in the transport of sea bass fry in plastic bag was also investigated. At 5 ppm, clove oil could reduce activities of the fish without loss of equilibrium (sedation stage) during the 4 hour simulated transport at 50 fish per 1,000 ml sea water (15 ppt). At 20 ppm, clove oil caused loss of equilibrium in fish resulting in the anesthesia stage throughout the 4 hour period. However, there was no improvement on survival rate and fish behavior with the use of clove oil during and after this 4 hour transport. Simulated transport at 50 fish per 500 ml sea water (15 ppt) for 8 hour did show better significant survival rate with additional of 5 and 20 ppm clove oil. In both short and long term transport study, clove oil did show the benefit by reducing the fish activities judging from the reduction of oxygen consumption, ammonia and carbon dioxide levels. Addition of appropriate concentration of clove oil in transport water ensured that the fish would stay calm by reducing fish activity and therefore, prevented any drastic changes of water qualities.

scholarly journals Rhythmic Clock Gene Expression in Atlantic Salmon Parr Brain

2021 ◽  
Vol 12 ◽  
Author(s):  
Charlotte M. Bolton ◽  
Michaël Bekaert ◽  
Mariann Eilertsen ◽  
Jon Vidar Helvik ◽  
Herve Migaud
Keyword(s):  
Atlantic Salmon ◽  
Clock Genes ◽  
Expression Patterns ◽  
Circadian Expression ◽  
Clock Gene Expression ◽  
Sister Clade ◽  
Before And After ◽  
Salmon Parr ◽  
Species Specific ◽  
Atlantic Salmon Parr

To better understand the complexity of clock genes in salmonids, a taxon with an additional whole genome duplication, an analysis was performed to identify and classify gene family members (clock, arntl, period, cryptochrome, nr1d, ror, and csnk1). The majority of clock genes, in zebrafish and Northern pike, appeared to be duplicated. In comparison to the 29 clock genes described in zebrafish, 48 clock genes were discovered in salmonid species. There was also evidence of species-specific reciprocal gene losses conserved to the Oncorhynchus sister clade. From the six period genes identified three were highly significantly rhythmic, and circadian in their expression patterns (per1a.1, per1a.2, per1b) and two was significantly rhythmically expressed (per2a, per2b). The transcriptomic study of juvenile Atlantic salmon (parr) brain tissues confirmed gene identification and revealed that there were 2,864 rhythmically expressed genes (p &lt; 0.001), including 1,215 genes with a circadian expression pattern, of which 11 were clock genes. The majority of circadian expressed genes peaked 2 h before and after daylight. These findings provide a foundation for further research into the function of clock genes circadian rhythmicity and the role of an enriched number of clock genes relating to seasonal driven life history in salmonids.

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