USE OF SYMMETRIC DIMETHYLARGININE TO DETECT RENAL LESIONS IN FISH: A PRELIMINARY STUDY IN BROOK TROUT (SALVELINUS FONTINALIS)

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.

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Brook trout passage performance through culverts

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2015-0089 ◽

2016 ◽

Vol 73 (1) ◽

pp. 94-104 ◽

Cited By ~ 18

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.

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Food Specialization By Individual Trout

Journal of the Fisheries Research Board of Canada ◽

10.1139/f72-248 ◽

1972 ◽

Vol 29 (11) ◽

pp. 1615-1624 ◽

Cited By ~ 91

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.

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