scholarly journals Brook trout passage performance through culverts

2016 ◽  
Vol 73 (1) ◽  
pp. 94-104 ◽  
Author(s):  
Elsa Goerig ◽  
Theodore Castro-Santos ◽  
Normand Émile Bergeron
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Structural Characteristics ◽  
Passive Integrated Transponder ◽  
Complex Interactions ◽  
Factors Influencing ◽  
Several Variables ◽  
And Behavior ◽  
Steep Slopes ◽  
Corrugated Metal

Culverts can restrict access to habitat for stream-dwelling fishes. We used passive integrated transponder telemetry to quantify passage performance of >1000 wild brook trout (Salvelinus fontinalis) attempting to pass 13 culverts in Quebec under a range of hydraulic and environmental conditions. Several variables influenced passage success, including complex interactions between physiology and behavior, hydraulics, and structural characteristics. The probability of successful passage was greater through corrugated metal culverts than through smooth ones, particularly among smaller fish. Trout were also more likely to pass at warmer temperatures, but this effect diminished above 15 °C. Passage was impeded at higher flows, through culverts with steep slopes, and those with deep downstream pools. This study provides insight on factors influencing brook trout capacity to pass culverts as well as a model to estimate passage success under various conditions, with an improved resolution and accuracy over existing approaches. It also presents methods that could be used to investigate passage success of other species, with implications for connectivity of the riverscape.

Comparative Ecology and Behavior of Domestic, Hybrid, and Wild Strains of Brook Trout, Salvelinus fontinalis, after Stocking

1990 ◽  
Vol 47 (12) ◽  
pp. 2285-2292 ◽  
Author(s):  
Stephanie Lachance ◽  
Pierre Magnan
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Niche Shift ◽  
Feeding Niche ◽  
Spatially Distributed ◽  
Wild Strains ◽  
Males And Females ◽  
Almost All ◽  
And Behavior ◽  
Sexually Mature

Two years after planting in six small oligotrophic lakes, domestic, hybrid and wild strains of brook trout, Salvelinus fontinalis, used space and food resources in the same way as native trout. Although trout living with or without white sucker, Catostomus commersoni, were similarly spatially distributed, they had different diets, suggesting a feeding niche shift of trout in the presence of sucker; we concluded that this shift is under phenotypic control because each planted strain came from similar genetic backgrounds. Sexual maturity was related to the size of individuals, regardless of the strain, and males matured before females. Almost all males and females were sexually mature in the first fall after stocking except wild females (3.0 and 75% matured during the first and second fall, respectively). Gonadosomatic indices (GSI) of domestic and hybrid females were similar during the first fall, but the GSI of domestic females was significantly higher than that of hybrid and wild strains in the second fail. Mean egg diameters were similar among the three strains during the two falls, but fecundity of domestic females, after correction for size differences, was significantly higher than that of hybrid females which, in turn, was significantly higher than that of wild ones.

scholarly journals Patients with first versus multiple episodes of self-harm: how do their profiles differ?

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Philippe Golay ◽  
Louise Ostertag ◽  
Alessandra Costanza ◽  
Bénédicte Van der Vaeren ◽  
Yves Dorogi ◽  
...  
Keyword(s):  
Emergency Department ◽  
Personality Disorder ◽  
Suicide Attempt ◽  
Professional Activity ◽  
Suicidal Risk ◽  
Factors Influencing ◽  
Several Variables ◽  
French Speaking ◽  
Self Harm ◽  
Multiple Episodes

Abstract Background Self-harm (SH) is among the strongest predictors of further episodes of SH, suicide attempt, and death by suicide. People who repeteadly harm themselves are at even higher risk for suicide. Factors influencing the repetition are important to identify when assessing suicidal risk and thereafter to offer specific interventions. Therefore, this study aimed to compare first versus multiple episodes characteristics in a large sample of patients in french-speaking Switzerland. Method We used the database from the French-speaking Swiss program for monitoring SH. Data of the psychiatric assessment of all adults admitted for SH were collected in the emergency department of four Swiss city hospitals between December 2016 and October 2019. Results 1730 episodes of SH were included. Several variables were significantly associated with multiple episodes, including diagnosis (over representation of personality disorders and under representation of anxiety disorders), professional activity (Invalidity insurance more frequent) and prior psychiatry care. Conclusions Patients suffering from a personality disorder and those with invalidity insurance are at risk for multiple episodes of SH and should be targeted with specific interventions.

Parasite-induced susceptibility to predation in diplostomiasis

Parasitology ◽  
1982 ◽  
Vol 85 (3) ◽  
pp. 495-501 ◽  
Author(s):  
P. Brassard ◽  
M. E. Rau ◽  
M. A. Curtis
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Marked Decrease ◽  
Infected Fish ◽  
Induced Susceptibility ◽  
Diplostomum Spathaceum

Guppies (Lebistes reticulatis) exposed to doses as low as 25 cercariae of Diplostomum spathaceum for 30 min were consistently and significantly more susceptible to predation by brook trout (Salvelinus fontinalis) than uninfected controls. The increase in susceptibility to predation was correlated with a marked decrease in the activity of infected fish.

Food Specialization By Individual Trout

1972 ◽  
Vol 29 (11) ◽  
pp. 1615-1624 ◽  
Author(s):  
James E. Bryan ◽  
P. A. Larkin
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Stomach Contents ◽  
Cutthroat Trout ◽  
Salmo Gairdneri ◽  
Potential Prey ◽  
Repeated Observation ◽  
Size Growth ◽  
Salmo Clarki

Analyses of stomach contents showed that the kinds of prey eaten by brook trout (Salvelinus fontinalis), cutthroat trout (Salmo clarki), and rainbow trout (Salmo gairdneri) were seldom distributed at random among the individuals. Repeated observation of food eaten by individuals in a stream and ponds showed that prey types were eaten in proportions which were characteristic for an individual.Specialization occurred on several different kinds of prey. Although the degree of specialization was higher during shorter intervals, the data suggested that some specialization persisted for half a year. There were no striking correlations between degree of specialization and other individual properties such as size, growth rate, weight of food, number of food items, previous specialization, or area of recapture.In addition to the observations on trout in relatively undisturbed habitats, a field experiment was conducted using laboratory-reared rainbow trout held in small ponds. The food of each trout in the experiment was sampled repeatedly. In analysis of variance, interaction among the individuals and kinds of prey eaten showed that food specialization occurred. Both the absolute and relative abundance of potential prey were constant during the experiment.

scholarly journals Concomitant Antibiotic and Mercury Resistance Among Gastrointestinal Microflora of Feral Brook Trout, Salvelinus fontinalis

2012 ◽  
Vol 65 (5) ◽  
pp. 575-582 ◽  
Author(s):  
Matthew M. Meredith ◽  
Erin M. Parry ◽  
Justin A. Guay ◽  
Nicholas O. Markham ◽  
G. Russell Danner ◽  
...  
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Mercury Resistance ◽  
Gastrointestinal Microflora
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