Blar i ICES CM documents authored by IMR scientists (1949-2011) på forfatter "Torrissen, Ole"
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Aluminium accumulation on eggs and hatching system during the incubation period - an important cause of variable hatching success ?
Ulgenes, Yngve; Torrissen, Ole (ICES CM Documents;1984/F:27, Working paper, 1984)Groups of rainbow trout eggs were incubated in duplicate in trays with PVC screens and original aluminium screens. During incubation aluminium bound to sediments was deposited on eggs and hatching systems. By adding ... -
Artificial hatching substrate in the mass rearing of larval Atlantic salmon (Salmo salar)
Hansen, Tom; Torrissen, Ole (ICES CM Documents;1984/F:30, Working paper, 1984)Eggs from individual Atlantic salmon (Salmo salar) were hatched in a Californian hatching system with and without an astro-turf artificial substrate and growth during the first 200 days following hatching was ... -
Artificial hatching substrate, effect on RNA / DNA ratio and protein retention during the yolk-sac period of Atlantic salmon (Salmo salar)
Taranger, Geir Lasse; Hansen, Tom; Torrissen, Ole; Raae, Arnt J. (ICES CM Documents;1985/F:31, Working paper, 1985)Genetical groups of Atlantic salmon (Salmo salar) were hatched in a Caiifonian hatching system with and without an astro-turf artificial hatching substrate, and were later transfered to separate feeding units. The ... -
Causes of variation in carcass traits of Atlantic salmon (Salmo salar)
Torrissen, Ole; Hansen, Tom; Torrissen, Krisna Rungruangsak; Nævdal, Gunnar (ICES CM Documents;1984/F:25, Working paper, 1984)The aim of the present study was to reveal causes of variation in carcass traits of farmed Atlantic salmon (Salmo salar). During slaughtering of one year class Atlantic salmon, composed of half sib and full sib groups, ... -
Effects of different rearing environments on the mortality of Atlantic salmon broodstock and eggs
Ulgenes, Yngve; Torrissen, Ole; Hansen, Tom (ICES CM Documents;1984/F:26, Working paper, 1984)Atlantic salmon (Salmo salar) reared for three years in seawater were moved to brackish- and freshwater before they matured. A control group matured in seawater. The groups were given different feeding regimes the last ... -
pH adjustment of acid water at Matre Aquaculture Station: Experiences with previous and existing methods
Ulgenes, Yngve; Hansen, Tom; Torrissen, Ole (ICES CM Documents;1984/F:28, Working paper, 1984)The water from Matre River is characterized as very soft, with a total hardness of 1. 5 - 2. 5 mg Ca0/1 and a very low buffer capacity. Acid precipitation results in low pH, values below 5. 0 are recorded every year. ... -
Physiological changes in blood and seminal plasma during the spawning period of maturing rainbow trout held under different temperature and salinity regimes, and the effect on survival of the broodstock and the eyed eggs
Albrektsen, Sissel; Torrissen, Ole (ICES CM Documents;1988/F:3, Working paper, 1988)Maturing rainbow trouts reared in sea cages were transferred to tanks and kept under nine different temperature and salinity regimes. Blood and seminal fluids were regularly sampled from the fish, and different organic ... -
Pigmentation of salmonid - a comparison of astaxanthin and cantaxanthin as pigment sources for rainbow trout
Torrissen, Ole (ICES CM Documents;1985/F:24, Working paper, 1985)Rainbow trout were fed a diet supplemented with astaxanthin and cantaxanthin. The ratios of astaxanthin to cantaxanthin were determined in plasma, faeces and flesh. During 65 days of feeding the flesh reached a level ... -
Pigmentation of salmonids: Factors affecting carotenoid deposition in rainbow trout (Salmo gairdneri)
Torrissen, Ole (ICES CM Documents;1984/F:23, Working paper, 1984)Factors affecting carotenoid deposition in rainbow trout (Salmo gairdneri) were investigated in three feeding experiments. The deposition of astaxanthin in the flesh increased significantly with increasing levels of ... -
Protease activities in the digestive tract of Atlantic salmon fry from five different river strains
Torrissen, Krisna Rungruangsak; Torrissen, Ole (ICES CM Documents;1982/M:11, Working paper, 1982) -
Sexual maturation: Effect on protease activities and carotenoid levels in Atlantic salmon (Salmo salar)
Torrissen, Krisna Rungruangsak; Torrissen, Ole (ICES CM Documents;1984/F:24, Working paper, 1984)Protease activities in the digestive tract and carotenoid levels in flesh, ovaries and plasma were determined in 4 to 4 1/2 year old Atlantic salmon (Salmo salar) during the period from early March until December. The ... -
The effect of a short time exposure to different temperature and salinity regimes on survival of maturing Atlantic salmon and eyed eggs, and changes in blood and seminal plasma during the spawning period
Albrektsen, Sissel; Nortvedt, Ragnar; Torrissen, Ole (ICES CM Documents;1986/F:25, Working paper, 1986)Maturing Atlantic salmon, transferred from brackish water two weeks prespawning, were held under four different temperature and salinity regimes through their spawning period. Values of blood glucose and haematocrit ... -
The effect of carotenoids on the development of roe and on growth rate of Atlantic salmon fry
Torrissen, Krisna Rungruangsak; Torrissen, Ole (ICES CM Documents;1982/M:12, Working paper, 1982) -
The effect of different photoperiods on growth and smoltification in Atlantic salmon (Salmo salar)
Stefansson, Sigurd O.; Hansen, Tom; Nævdal, Gunnar; Torrissen, Ole (ICES CM Documents;1985/F:32, Working paper, 1985)Photoperiod has been implicated as an effective mediator of growth and smelting in Atlantic salmon (Salmo salar). To investigate this 0+ parr of Atlantic salmon were treated with three different photoperiods: 24Light:0Dark; ... -
The effect of illumination on alevins of Atlantic salmon (Salmo salar) and rainbow trout (S. gairdneri), incubated on different substrates
Nortvedt, Ragnar; Hansen, Tom; Holm, Marianne; Torrissen, Ole (ICES CM Documents;1985/F:27, Working paper, 1985)Atlantic salmon (Salmo salar) and rainbow trout (S. gairdneri) eggs were incubated in plexi-glass aquariums. After hatching, alevins were kept in darkness, two groups of each species without substrate, two groups in ... -
The effects of light on the mortality of different pigmented atlantic salmon (Salmo salar) eggs.
Torrissen, Krisna Rungruangsak; Torrissen, Ole (ICES CM Documents;1981/M:16, Working paper, 1981)