Crustacean Plankton Communities of the Matamek River System and their Variation with Predation

1975 ◽  
Vol 32 (12) ◽  
pp. 2530-2535 ◽  
Author(s):  
G. F. Pope ◽  
J. C. H. Carter
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
River System ◽  
Crustacean Plankton ◽  
Almost All ◽  
Plankton Communities

The crustacean plankton communities of lakes with fish planktivores and low densities of Chaoborus larvae contained greater numbers of noncyclopoid crustacean predators but lower numbers of the larger herbivores. Lakes with brook trout (Salvelinus fontinalis) only and low densities of Chaoborus larvae, had plankton communities whose biomasses were dominated by the larger herbivores. The communities of lakes with no fish and high densities of larvae were dominated by the smaller herbivores, although the larger species were present in some. The noncyclopoid, crustacean predators were absent from almost all of these lakes.

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.

Population sizes of metazoan parasites of brook trout (Salvelinus fontinalis) and Atlantic salmon (Salmo salar) in a small Newfoundland lake

1984 ◽  
Vol 62 (1) ◽  
pp. 130-133 ◽  
Author(s):  
D. K. Cone ◽  
P. M. Ryan
Keyword(s):  
Salmo Salar ◽  
Brook Trout ◽  
Gasterosteus Aculeatus ◽  
Salvelinus Fontinalis ◽  
Parasite Community ◽  
Fish Population ◽  
Population Estimates ◽  
Infection Prevalence ◽  
Metazoan Parasites ◽  
Almost All

The metazoan parasite community of fishes (Salvelinus fontinalis, Salmo salar, Gasterosteus aculeatus) in a small lake in central Newfoundland, Canada, was studied. It consisted of three components: parasites of salmonids (Salmincola spp., Discocotyle sagittata, Apophallus imperator, Diplostomum sp., Tetracotyle sp. 1, Cystidicoloides tenuissima, Eubothrium salvelini, Diphyllobothrium sp., glochidia), parasites of sticklebacks (Gyrodactylus avalonia, Tetracotyle sp. 2, Shistocephalus solidus), and parasites shared by salmonids and sticklebacks (Ergasilus sp., Metechinorhynchus lateralis, Crepidostomum farionis). Population estimates were made of the salmonid fishes by the Schnabel mark–recapture method. By multiplying infection prevalence × intensity × number of fish, population estimates were obtained for each species of salmonid parasite. This information revealed that S. fontinalis carries almost all of the salmonid parasite populations and that the seaward migration of S. salar at 2–5 years of age is an insignificant loss to the parasite community. It also revealed that the majority of the population of C. tenuissima, M. lateralis, and Ergasilus sp. is carried by the more abundant small fishes, while the majority of the population of D. sagittata, A. imperator, Tetracotyle sp. 1, and S. edwardsii is carried by the less abundant large hosts. Possible reasons for these two distributions are discussed.

scholarly journals Specific Niche Characteristics Facilitate the Invasion of an Alien Fish Invader in Boreal Streams

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Kai Korsu ◽  
Jani Heino ◽  
Ari Huusko ◽  
Timo Muotka
Keyword(s):  
Fish Species ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
River System ◽  
Environmental Variable ◽  
Environmental Niche ◽  
Niche Space ◽  
Boreal Streams ◽  
Alien Fish ◽  
Alien Invader

We studied the ecological niche relations of native stream fish and an alien invader, brook trout (Salvelinus fontinalis), to examine if brook trout had located an underused environmental niche in our boreal study system. In both study years (1994 versus 2004), we found brook trout to have the most marginal niche position of all the fish species examined. The most important environmental variable affecting the distribution of brook trout was pH, with acid headwater sites being dominated by this species. Brown trout, in contrast, had relatively nonmarginal niche, occurring in average conditions across the sampled sites. Other fish species had niche positions between the two salmonids. Our results show that fish invasions may be strongly facilitated by the presence of suboptimally occupied environmental niche space in the recipient river system.

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.

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.

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.

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