Influence of fish density on the energy allocation pattern of juvenile brook trout (Salvelinus fontinalis)

1998 ◽  
Vol 55 (4) ◽  
pp. 796-805 ◽  
Author(s):  
François Marchand ◽  
Daniel Boisclair

Our objectives were (i) to assess the influence of fish density on the energy allocation pattern of juvenile brook trout (Salvelinus fontinalis) and (ii) to define the mechanism by which this influence occurs. We estimated growth, consumption, and activity rates of brook trout held in 8-m3 enclosures characterized by two different densities (four or eight fish per enclosure; D4 and D8 enclosures, respectively). Eight experiments designed to estimate these variables were performed during a 27-day period. Fish from D4 enclosures ( DELTA W bar = 0.46 g) grew twice as much as those from D8 enclosures ( DELTA W bar = 0.24 g). For any given experiment, consumption rates were not significantly different between the two fish densities (0.434-1.09 g dry ·100 g wet-1 ·day-1). However, fish stocked in D8 enclosures displayed more aggressive behavior, executed 5.5 times more movements, and swam at speeds 13% faster than fish in D4 enclosures. These differences resulted in activity rates fourfold higher in D8 enclosures than in D4 enclosures. Empirical analyses combining our results with published values of growth, consumption, and activity rates supported the hypothesis that competition can have a negative effect on growth through a decrease in consumption rates and an increase in activity costs.

1992 ◽  
Vol 49 (12) ◽  
pp. 2566-2573 ◽  
Author(s):  
Daniel Boisclair

I tested the hypothesis of the existence of a significant positive linear relationship between activity and consumption rates for an actively foraging fish. Within-day variations in activity rates of 0 + brook trout (Salvelinus fontinalis) kept in enclosures were estimated using an underwater videocamera system. Consumption rates at different periods of that day were estimated using the variations of the digestive tract contents. Total consumption rates (i.e. sum of food ingested by all fish) ranged from values close to zero (−1.4 to 0.9; 12:30–24:00) to 12.7 cal/30 min (08:30–09:00). Total activity rates ranged from 0.06 (14:00–14:30) to 2.94 cal/30 min (08:30–09:00). My results indicate that, under specific environmental conditions, activity rates of brook trout are positively related to their feeding rates and, consequently, that the behavior of this actively foraging fish can result in the reduction of the energy losses associated with swimming during nonfeeding periods. My work also permits the development of an experimental protocol to test hypotheses regarding energy allocation patterns between growth, consumption, and activity rates on a multiday basis.


2003 ◽  
Vol 60 (4) ◽  
pp. 401-410 ◽  
Author(s):  
Geneviève R Morinville ◽  
Joseph B Rasmussen

Many salmonids, including brook trout (Salvelinus fontinalis), contain both anadromous (migrant) and nonanadromous (resident) forms within a population (partial migration). Although partial migration is commonly observed, the mechanisms governing the adoption of migration or residency are poorly understood. We used field estimates of fish growth coupled with in situ estimates of food consumption rates to demonstrate that a trade-off exists between the ability to efficiently exploit local environments (resident approach) and the capacity to capitalize from large-scale environmental heterogeneity (migrant approach). We demonstrate that in the year before migration, migrant brook trout have consumption rates 1.4 times higher than those of resident brook trout. However, migrants have lower growth efficiencies (ratio of growth to consumption) than residents, indicating that migrants have higher metabolic costs. Residents and migrants also differed in their stable carbon isotope signatures (δ13C), a time-integrated measure that has been linked to habitat use. Fish muscle δ13C of migrants was depleted by 1 ± 0.1‰ compared with that of residents, and this could not be explained by any biases introduced by the time of sampling or the size of fish sampled. Our findings thus agree with the notion that a link exists between metabolic costs (efficiency) and the adopted life-history strategy.


2013 ◽  
Vol 91 (9) ◽  
pp. 619-625 ◽  
Author(s):  
Will G. Warnock ◽  
Joseph B. Rasmussen

In this experiment, competition was observed among native bull trout (Salvelinus confluentus (Suckley, 1859)) and non-native brook trout (Salvelinus fontinalis (Mitchill, 1814)) in artificial streams. In intraspecific competitions, brook trout engaged in territorial interference foraging strategies, and their foraging success was correlated with occupancy of the lead position in the stream. No correlation was apparent for bull trout, most of which engaged in nonterritorial scramble foraging tactics. In interspecific competitions, four stream environments were constructed in which fish density, habitat complexity, and current velocity were altered. Bull trout outcompeted brook trout for food in simple pool habitat devoid of cover when competition was head-to-head (density = 3 fish·m−2) between the species. When competitor number was doubled in this habitat, the two became equal competitors. At this higher density, bull trout again outcompeted brook trout for food when the habitat was changed to a complex riffle with substrate cover. Brook trout were more aggressive towards bull trout than vice versa, and interspecific aggression was decreased by low density, cover, and high stream velocity. Territorial brook trout aggressively interfere with their competitor for access to resources, but the success and intensity of this tactic against bull trout may be mitigated by environmental factors.


1999 ◽  
Vol 56 (5) ◽  
pp. 875-887 ◽  
Author(s):  
S Tucker ◽  
J B Rasmussen

Through the 137Cs mass balance method, annual consumption rates were estimated for juvenile Atlantic salmon (Salmo salar) parr and precocious males as well as for brook trout (Salvelinus fontinalis) at four sites in the Ste-Marguerite River system, Québec. With explicit age analysis, consumption rates and growth rates were derived on an individual fish and age-class basis. These represent the first consumption estimates for Atlantic salmon in the wild. Precocious males had consumption rates 1.5 times greater than nonmaturing parr, while Atlantic salmon parr consumption rates were 2.7 times greater than brook trout. There was a strong positive relationship between individual annual consumption and growth rates for Atlantic salmon and brook trout at all sites. Subsequently the concept of field maintenance ration was introduced as the intercept of consumption over growth. Maintenance rations for Atlantic salmon parr ranged from 0.010 to 0.016 g·g-1·day-1 between sites. Brook trout had maintenance rations approximately half those of Atlantic salmon at 0.0059 g·g-1·day-1. Precocious male growth efficiencies were half those of nonmaturing parr despite higher feeding and growth rates. Brook trout growth efficiencies were significantly greater than those of Atlantic salmon parr. The lower growth efficiencies observed for Atlantic salmon are likely due to increased metabolic costs associated with higher activity. On average, Atlantic salmon parr spent 2.4-fold more energy in activity than brook trout. Atlantic salmon precocious males spent 1.7 times more energy in activity than parr.


2001 ◽  
Vol 58 (2) ◽  
pp. 386-393 ◽  
Author(s):  
John A Sweka ◽  
Kyle J Hartman

Brook trout (Salvelinus fontinalis) were held in an artificial stream to observe the influence of turbidity on mean daily consumption and specific growth rates. Treatment turbidity levels ranged from clear (<3.0 nephelometric turbidity units (NTU)) to very turbid water (> 40 NTU). Observed mean daily specific consumption rates were standardized to the mean weight of all brook trout tested. Turbidity had no significant effect on mean daily consumption, but specific growth rates decreased significantly as turbidity increased. Brook trout in turbid water became more active and switched foraging strategies from drift feeding to active searching. This switch was energetically costly and resulted in lower specific growth rates in turbid water as compared with clear water. Bioenergetics simulations were run to compare observed growth with that predicted by the model. Observed growth values fell below those predicted by the model and the difference increased as turbidity increased. Abiotic factors, such as turbidity, which bring about changes in the activity rates of fish, can have implications for the accuracy of predicted growth by bioenergetics models.


Parasitology ◽  
1982 ◽  
Vol 85 (3) ◽  
pp. 495-501 ◽  
Author(s):  
P. Brassard ◽  
M. E. Rau ◽  
M. A. Curtis

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.


2016 ◽  
Vol 73 (1) ◽  
pp. 94-104 ◽  
Author(s):  
Elsa Goerig ◽  
Theodore Castro-Santos ◽  
Normand Émile Bergeron

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.


1972 ◽  
Vol 29 (11) ◽  
pp. 1615-1624 ◽  
Author(s):  
James E. Bryan ◽  
P. A. Larkin

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.


Sign in / Sign up

Export Citation Format

Share Document