The effects of cadmium on prolactin cell activity and plasma cortisol levels in the rainbow trout (Salmo gairdneri)

1986 ◽  
Vol 8 (4) ◽  
pp. 273-280 ◽  
Author(s):  
V.A. James ◽  
T. Wigham
Keyword(s):  
Rainbow Trout ◽  
Plasma Cortisol ◽  
Cell Activity ◽  
Salmo Gairdneri ◽  
Prolactin Cell ◽  
Cortisol Levels

Plasma Cortisol Levels of Fingerling Rainbow Trout (Salmo gairdneri) at Rest, and Subjected to Handling, Confinement, Transport, and Stocking

1980 ◽  
Vol 37 (5) ◽  
pp. 805-811 ◽  
Author(s):  
Bruce A. Barton ◽  
Richard E. Peter ◽  
Christine R. Paulencu
Keyword(s):  
Rainbow Trout ◽  
Plasma Cortisol ◽  
Gradual Increase ◽  
Salmo Gairdneri ◽  
Gradual Decline ◽  
Sharp Rise ◽  
Daily Cycle ◽  
Handling Stress ◽  
Gentle Agitation ◽  
Cortisol Levels

Fingerling rainbow trout, acclimated to hatchery raceways or laboratory aquaria, had low plasma cortisol levels (≤ 2 ng/mL), with no apparent daily cycle in levels. Netting of cohorts out of an aquarium, without agitation, did not cause a rise in plasma cortisol concentrations in remaining fish. However, following 90 s of handling and confinement by netting, fingerlings had a sharp rise in plasma cortisol to a peak at 15 min, and then a gradual decline to the basal level over 2 h. Gentle agitation and intermittent restraint with a dip net in the aquarium caused a gradual increase in plasma cortisol concentrations. Intense handling and severe confinement caused a rapid increase in plasma cortisol to a plateau, two to four times greater than the peak levels found in fingerlings subjected to the less vigorous stressors; high levels of plasma cortisol were maintained to the median tolerance limit. During a stocking operation, there was a rapid rise in plasma cortisol concentrations during the initial capture from the rearing ponds, and high levels were maintained through to stocking into the lake 6 h and 10 min later, although a small decrease occurred during transit while the fish were in the truck tanks. After stocking, plasma cortisol concentrations in caged fingerlings did not decrease to the basal level until 8 d poststocking.Key words: rainbow trout, fingerlings, plasma cortisol, cycles, handling stress, stocking stress

DIFFERENCES IN CONCENTRATIONS OF PLASMA CORTISOL IN THE TROUT AND THE EEL FOLLOWING ADAPTATION TO BLACK OR WHITE BACKGROUNDS

1981 ◽  
Vol 89 (1) ◽  
pp. 135-140 ◽  
Author(s):  
BRIDGET I. BAKER ◽  
THERESA A. RANCE
Keyword(s):  
Rainbow Trout ◽  
Plasma Cortisol ◽  
Binding Capacity ◽  
Anguilla Anguilla ◽  
Short Photoperiod ◽  
Salmo Gairdneri ◽  
Pars Intermedia ◽  
Total Cortisol ◽  
The Difference ◽  
Long Photoperiod

When rainbow trout (Salmo gairdneri) and eels (Anguilla anguilla) were kept in black tanks for 3—4 weeks, their plasma cortisol titres were about fourfold higher than in fish kept in white tanks. In trout, the difference was apparent only under a long photoperiod of 16 h light: 8 h darkness, but in eels the difference was clear under both a long or short photoperiod (9·5 h light: 14·5 h darkness). It is suggested that the increase in plasma cortisol seen in black-adapted fish is dependent on either ACTH or MSH secreted by the pars intermedia melanotrophs. No difference was seen either in the total cortisol-binding capacity of the plasma nor in interrenal histology in trout from black or white backgrounds.

scholarly journals A novel emotional and cognitive approach to welfare phenotyping in rainbow trout exposed to poor water quality

2018 ◽  
Author(s):  
V Colson ◽  
A Mure ◽  
C Valotaire ◽  
JM Le Calvez ◽  
L Goardon ◽  
...  
Keyword(s):  
Water Quality ◽  
Rainbow Trout ◽  
Social Isolation ◽  
Plasma Cortisol ◽  
Fish Welfare ◽  
Cognitive Approach ◽  
Human Presence ◽  
Novel Environment ◽  
Poor Water Quality ◽  
Cortisol Levels

AbstractRecent scientific evidence for fish sentience has stressed the need for novel sentience-based detection tools of fish welfare impairment in commercial farms. In order to mimic a well-characterised stress situation, rainbow trout (Oncorhynchus mykiss) were exposed to poor water quality (hypoxia combined with high ammonia level) for three weeks (stressed group, S) and compared to a non-stressed control group (NS). After a return to water quality standard, emotional responses were assessed in fish subjected to two potentially threatening situations: (i) social isolation in a novel environment and (ii) human presence. In addition, we used an appetitive-conditioning paradigm to determine whether previous chronic deterioration of water quality disturbs cognitive abilities in fish. Spontaneous behaviour in the tanks was also recorded during the environmental challenge as a reference for fish activity. We observed that in S fish, plasma cortisol levels were increased before and after social isolation in a novel environment compared to the plasma cortisol levels in the NS group, despite the absence of a behavioural difference between the two groups. Under deteriorated water quality, fish locomotor activity was globally reduced and this reduction was correlated to increased shoaling behaviour. Farmers can use these first behavioural modifications as a sentinel detector for fish welfare impairment. More importantly, we demonstrated that reactivity to a human presence in a home-environment and food-anticipatory behaviour were both inhibited in the S group. We consider that these two sentience-based tests are highly relevant for fish welfare assessment at the group level and are easy to use in the aquaculture industry.

scholarly journals Elevation of plasma somatolactin concentrations during acidosis in rainbow trout (Oncorhynchus mykiss)

1996 ◽  
Vol 199 (5) ◽  
pp. 1043-1051 ◽  
Author(s):  
S Kakizawa ◽  
T Kaneko ◽  
T Hirano
Keyword(s):  
Rainbow Trout ◽  
Plasma Cortisol ◽  
Initial Level ◽  
Plasma Concentrations ◽  
Water Acidification ◽  
Acid Base ◽  
Exposed Fish ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Blood Ph ◽  
Cortisol Levels

Somatolactin (SL) is a putative pituitary hormone of the growth hormone (GH)/prolactin (PRL) family in fish; its physiological function has yet to be determined. Acidosis was induced in rainbow trout (Oncorhynchus mykiss) by exposure to acidic water (pH 4.5) or by exhaustive exercise, and plasma concentrations of SL, PRL and GH as well as other plasma parameters were examined. A decrease in blood pH was observed in fish from 1 day after water acidification until the end of the experiment at day 7. Plasma SL levels in the acid-exposed fish increased, reached a peak on day 1 and then returned to the initial level by day 4. No change was seen in plasma concentrations of PRL throughout the experiment. Plasma levels of GH, in contrast, decreased in the acid-exposed fish on days 2 and 4. Plasma cortisol levels in the acid-exposed fish were higher than the control level on days 4 and 7, although plasma cortisol levels did not increase above the initial level in response to water acidification. There was no significant change in the expression of SL-, PRL- and GH-mRNA in the pituitary gland. Levels of plasma Na+ and lactate were reduced 12 h after water acidification and remained low throughout the experiment. Exhaustive exercise in shallow water at neutral pH (7.5) resulted in a transient but pronounced acidosis, associated with increases in plasma SL, cortisol, Ca2+, phosphate and lactate levels. Plasma SL levels returned to the initial level along with the recovery of blood acid-base status. In contrast, plasma cortisol levels stayed elevated even 24 h after exercise. There was no correlation between plasma PRL and GH levels and blood pH. Elevation of plasma SL levels during acidosis suggests the possible involvement of SL in acid-base regulation in rainbow trout.

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