HISTOPHYSIOLOGICAL STUDIES ON THE JUVENILE ATLANTIC SALMON (SALMO SALAR) RETINA: I. RATES OF LIGHT- AND DARK-ADAPTATION

1961 ◽  
Vol 39 (2) ◽  
pp. 123-128 ◽  
Author(s):  
M. A. Ali ◽  
W. R. Stevenson ◽  
Judith S. Press
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Dark Adaptation ◽  
Light Adaptation ◽  
Pacific Salmon ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
The Pacific

The structure of the Atlantic salmon retina corresponds to descriptions by previous workers and is also similar to that of the Pacific salmon retina. Retinal epithelial pigment light-adapts in 60 minutes. Cones light-adapt in 45 minutes. Dark-adaptation of the pigment and cones occurs in 70 minutes. Retinal index shows light-adaptation occurring in 60 minutes and dark-adaptation in 70 minutes. Results are compared with those of the Pacific salmon's.

HISTOPHYSIOLOGICAL STUDIES ON THE JUVENILE ATLANTIC SALMON (SALMO SALAR) RETINA: II. RESPONSES TO LIGHT INTENSITIES, WAVELENGTHS, TEMPERATURES, AND CONTINUOUS LIGHT OR DARK

1961 ◽  
Vol 39 (4) ◽  
pp. 511-526 ◽  
Author(s):  
M. A. Ali
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Dark Adaptation ◽  
Pacific Salmon ◽  
Retinal Pigment ◽  
Continuous Light ◽  
Visible Spectrum ◽  
Dark Pigment ◽  
Atlantic Salmon Salmo Salar ◽  
Light Intensities

Retinal epithelial pigment dark-adapts in intensities below 10−3 ft-c. Cones are in a light-adapted state in intensities of 10−2 ft-c and above, semiadapted state in 10−3 ft-c, and dark-adapted state in 10−4 ft-c and below. The retinal index corresponds to the response of cones. It is suggested that the visible spectrum of the yearling Atlantic salmon ranges from 3640 Å to 6900 Å because the retina is in a light-adapted state in that range. In light, lower and higher temperatures bring about an expansion of the retinal pigment. Cones and retinal index are not affected. In dark, pigment expands with higher temperatures but temperatures exceeding 18.3 °C bring forth contraction. Cones contract with increasing temperatures but beyond 14.8 °C they expand. The retinal index indicates a greater dark-adaptation of retina with increasing temperatures between 5.0 °C and 18.3 °C but higher temperatures make it less dark-adapted. Cones exhibit no rhythm in their positions in continuous light or dark. Pigment demonstrates no rhythm in light but shows one in dark which persists for a day. The significance of the results is discussed. Comparisons with results with Pacific salmon are made.

scholarly journals Sulphated glycosaminoglycans and proteoglycans in the developing vertebral column of juvenile Atlantic salmon (Salmo salar)

2015 ◽  
Vol 41 (4) ◽  
pp. 1029-1051 ◽  
Author(s):  
Kirsten O. Hannesson ◽  
Elisabeth Ytteborg ◽  
Harald Takle ◽  
Grethe Enersen ◽  
Grete Bæverfjord ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Vertebral Column ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Sulphated Glycosaminoglycans

Effect of time of day, time of year, and life history strategy on time budgeting in juvenile Atlantic salmon, Salmo salar

1999 ◽  
Vol 56 (12) ◽  
pp. 2397-2403 ◽  
Author(s):  
Sveinn K Valdimarsson ◽  
Neil B Metcalfe
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Life History Strategy ◽  
Time Of Day ◽  
Life History Strategies ◽  
Foraging Efficiency ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Time Of Year

Traditionally, behavioural studies on juvenile Atlantic salmon, Salmo salar, have been conducted during the day in summer. It is known that Atlantic salmon become nocturnal in winter, but very little is known about their behaviour at that time. Therefore, observations in a seminatural stream were carried out during the day and night, from February to June, comparing diel and seasonal differences in behaviour between fish adopting alternative life history strategies. The results showed a general trend for more activity in spring than in winter, and the fish were found to be foraging at surprisingly low light levels. There were differences in relative feeding rate between the life history strategies; the early migrant fish foraged mostly during the day whereas the delayed migrant fish did more foraging at night. There is some evidence that the early migrant fish made fewer feeding attempts over the winter, which is surprising, since they grow faster over that period. This suggests differences in foraging efficiency, which could contribute to the separation into these two life history strategies.

Thermal performance of juvenile Atlantic Salmon, Salmo salar L.

2001 ◽  
Vol 15 (6) ◽  
pp. 701-711 ◽  
Author(s):  
B. JONSSON ◽  
T. FORSETH ◽  
A. J. JENSEN ◽  
T. F. NAESJE
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Thermal Performance ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon
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