Impact of Brook Trout (Salvelinus fontinalis) Predation on the Crayfish Orconectes virilis in Three Michigan Lakes

1979 ◽  
Vol 36 (10) ◽  
pp. 1191-1196 ◽  
Author(s):  
H. Gowing ◽  
W. T. Momot
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
First Year ◽  
Orconectes Virilis ◽  
Trout Population ◽  
Production Growth ◽  
First Year Of Life ◽  
The Cost ◽  
Slow Growing ◽  
Northern Michigan

The crayfish Orconectes virilis is a major component of the benthos of three small lakes in northern Michigan. These lakes contained stocked brook trout (Salvelinus fontinalis) populations (age-0 and age-I) at densities of 188, 411, and 1398 fish/ha. Crayfish were preyed upon by brook trout, but only during their first year of life. Two-year production of age-0 crayfish was approximately 94 kg in each lake; brook trout consumed only about 1–2% in lakes with lower density offish. Even with greater trout density and accompanying higher rate of exploitation (40%), there was no impact on recruitment of young crayfish because compensatory mortality of crayfish occurred in lakes with less trout predation. However, stocking trout at higher densities decreased trout growth and condition. While 2-yr production was highest (59 kg/ha) in the lake stocked at the highest density and lowest (17 kg/ha) in one stocked at the lowest density, the former was achieved at the cost of a very slow growing trout population. Most of the crayfish production is not utilized as trout food but enters the non-predatory pool of detrital organic matter. Key words: Orconectes virilis, brook trout, predation, production growth, mortality

Experimental Plantings of Brook Trout (Salvelinus fontinalis) from Furunculosis-Infected Stock

1968 ◽  
Vol 25 (12) ◽  
pp. 2643-2649 ◽  
Author(s):  
L. A. McDermott ◽  
A. H. Berst
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Infected Fish ◽  
Aeromonas Salmonicida ◽  
Control Fish ◽  
Southern Ontario ◽  
Trout Population ◽  
Hatchery Stock ◽  
Associated Species ◽  
Made In

Preliminary sampling revealed the presence of furunculosis disease in the resident brook trout population of the southern Ontario trout stream used in this study.Two plantings of marked yearling brook trout were made in the study area in 1966; one in the spring, and the other in the fall. The spring planting consisted of 1000 brook trout with a predetermined incidence of furunculosis infection and an equal number of trout with no evidence of infection. The fall planting consisted of 2000 brook trout with a known incidence of furunculosis infection.The stream was electrofished periodically during the 2-year period after the first planting. A total of 445 brook trout (140 of the planted hatchery stock, and 305 resident trout) and 127 fish of associated species were captured and examined for the presence of Aeromonas salmonicida, causative agent of furunculosis.Recovery rates of the "infected" and "noninfected" stocks of brook trout were similar, and there was no evidence of transmission of A. salmonicida from the infected fish to the control fish, nor the resident population of brook trout and other species of fish captured.

scholarly journals Brook trout (Salvelinus fontinalis) extinction in small boreal lakes revealed by ephippia pigmentation: a preliminary analysis

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Alexandre Bérubé Tellier ◽  
Paul E. Drevnick ◽  
Andrea Bertolo
Keyword(s):  
Brook Trout ◽  
Fish Assemblages ◽  
Salvelinus Fontinalis ◽  
Sediment Cores ◽  
Experimental Studies ◽  
Cost Effective ◽  
Fish Predation ◽  
Boreal Lakes ◽  
Predation Pressure ◽  
Trout Population

<p>Ephippium pigmentation is a plastic trait which can be related to a trade-off between visual predation pressure and better protection of cladoceran eggs against different types of stress. Experimental studies showed that planktivorous fish exert a greater predation pressure on individuals carrying darker ephippia, but little is known about the variation of ephippium pigmentation along gradients of fish predation pressure in natural conditions. For this study, our experimental design included four small boreal lakes with known fish assemblages. Two of the lakes have viable brook trout (<em>Salvelinus fontinalis</em>) populations, whereas the other two lakes experienced brook trout extinctions during the 20<sup>th</sup> century. Cladoceran ephippia were extracted from sediment cores at layers corresponding to the documented post- extinction phase (1990's) and from an older layer (1950's) for which the brook trout population status is not known precisely. Our first objective was to determine whether brook trout extinction has a direct effect on both ephippium pigmentation and size. Our second objective was to give a preliminary assessment of the status of brook trout populations in the 1950's by comparing the variation in ephippia traits measured from this layer to those measured in the 1990's, for which the extinction patterns are well known. Cost-effective image analysis was used to assess variation in pigmentation levels in ephippia. This approach provided a proxy for the amount of melanin invested in each ephippium analysed. Our study clearly shows that ephippium pigmentation may represent a better indicator of the presence of fish predators than ephippium size, a trait that showed a less clear pattern of variation between lakes with and without fish. For the 1990's period, ephippia from fishless lakes were darker and showed a slight tendency to be larger than ephippia from lakes with brook trout. However, no clear differences in either ephippium size or pigmentation were observed between the 1990's and 1950's layers within each lake. This suggests that brook trout extinction already occurred before the 1950’s, or that brook trout population abundance was already extremely low before and after the 1990’s. Our preliminary study shows that ephippium pigmentation can be used as a tool to quickly assess present and past predation levels on zooplankton when only sediment samples are available.</p>

The Cost of Prematurity: Hospital Charges at Birth and Frequency of Rehospitalizations and Acute Care Visits over the First Year of Life

2005 ◽  
Vol 105 (7) ◽  
pp. 56-64 ◽  
Author(s):  
Katherine D. Cuevas ◽  
Debra R. Silver ◽  
Dorothy Brooten ◽  
JoAnne M. Youngblut ◽  
Charles M. Bobo
Keyword(s):  
Acute Care ◽  
Hospital Charges ◽  
First Year ◽  
First Year Of Life ◽  
The Cost

Population Dynamics of Percids in Lake IJssel and some Smaller Lakes in The Netherlands

1977 ◽  
Vol 34 (10) ◽  
pp. 1710-1719 ◽  
Author(s):  
J. Willemsen
Keyword(s):  
Population Dynamics ◽  
Perca Fluviatilis ◽  
First Year ◽  
Homing Behavior ◽  
Perch Perca Fluviatilis ◽  
Class Strength ◽  
High Summer Temperature ◽  
Dependent Growth ◽  
First Year Of Life ◽  
Slow Growing

Pikeperch (Stizostedion lucioperca) and Eurasian perch (Perca fluviatilis) in Lake IJssel both prey mainly upon the very abundant smelt (Osmerus eperlanus). But competition for food is of little or no importance and growth is not density-dependent. Growth rates for perch and ruffe (Gymnocephalus cernua) in some lakes are exceptionally rapid, mean lengths after 3 yr being 24 and 18 cm, respectively. Very intensive fishing for pikeperch (total annual mortality 81%) in the season before first spawning removes particularly the fast-growing fish from the population, thus restricting reproduction mainly to the slow-growing pikeperch. Year-class strength of pikeperch is strongly favored by a high summer temperature during the first year of life. Strong year-classes of pikeperch in Lake IJssel are characterized by a mean length of the young-of-the-year of 14.5 cm or more. Migration of pikeperch and perch in Lake IJssel is restricted. When transported to other areas of the lake, both species showed a distinct homing behavior. Key words: Percidae, population dynamics, Stizostedion, Perca, Gymnocephalus

Influence of body weight, swimming characteristics, and water temperature on the cost of swimming in brook trout (Salvelinus fontinalis)

2000 ◽  
Vol 57 (7) ◽  
pp. 1482-1488 ◽  
Author(s):  
Ming Tang ◽  
Daniel Boisclair ◽  
Chantal Ménard ◽  
John A Downing
Keyword(s):  
Experimental Data ◽  
Water Temperature ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Significant Proportion ◽  
Average Difference ◽  
Fish Swimming ◽  
Experimental Conditions ◽  
Fish Weight ◽  
The Cost

We performed respirometry experiments to estimate the spontaneous swimming costs of brook trout (Salvelinus fontinalis) for 24 combinations of fish weight (3.5, 17, and 32 g), water temperature (4, 12, and 18°C), and respirometer size (27, 54, and 108 L). Fish swimming characteristics were estimated for each experiment using videocamera recordings and image analysis. Under our experimental conditions, average swimming characteristics of fish, such as swimming speed and turning and acceleration rates, varied from 2.5- to 29-fold. Our data, alone or combined with similar published results on brook trout weighing 1 g, indicated that fish weight was the only variable that could explain a statistically significant proportion of the variations of spontaneous swimming costs for that species (r2 = 0.91). Our work confirms, with a wider range of experimental data, that spontaneous swimming costs of fish are 3- to 22-fold (8-fold average difference) more energy demanding than predicted by forced swimming models developed using fish swimming at constant speeds and directions in flumes.

Trout Production and Eels in Bill Lake, Saguenay County, Quebec

1973 ◽  
Vol 30 (9) ◽  
pp. 1398-1401 ◽  
Author(s):  
J. F. O’Connor ◽  
G. Power
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Annual Production ◽  
Anguilla Rostrata ◽  
Apparent Position ◽  
Trout Population ◽  
American Eels

Competition and predation by American eels (Anguilla rostrata) is believed to have substantially reduced trout population and production in Bill Lake. Brook trout (Salvelinus fontinalis) occurred at densities of 7/ha; biomass of 0.34 kg/ha and annual production was estimated at 0.21 kg/ha. This is considerably less than values for trout density, biomass, and production in other lakes in the Matamek watershed from which eels appear to be absent. Eels in Bill Lake are old and large but not numerous, in keeping with their apparent position as top carnivores.

Brook Trout (Salvelinus fontinalis) Population Structure in Acidified Lac Tantaré, Quebec

1984 ◽  
Vol 41 (6) ◽  
pp. 865-877 ◽  
Author(s):  
Jean-Jacques Frenette ◽  
Julian J. Dodson
Keyword(s):  
Population Structure ◽  
Brook Trout ◽  
Sexual Maturity ◽  
Reproductive Effort ◽  
Salvelinus Fontinalis ◽  
Individual Growth ◽  
Toxic Stress ◽  
Age Classes ◽  
Recruitment Failure ◽  
Trout Population

To present evidence of acid-induced stress, we studied the population structure and distribution of brook trout (Salvelinus fontinalis) in acidified Lac Tantaré, Quebec. Trout greater than 21 cm (FL) represented only 16.2 and 10% of the population sampled in 1979 and 1980, respectively. Survival rates of trout from 1979 to 1980 indicated higher survival among individuals > 25 cm, mortality occurring primarily among fish of 13–25 cm. The marked decline in numbers of fish occurring at 21 cm coincided with the size at which 50% of the female trout population reached sexual maturity, suggesting that postspawning mortality contributes to the high mortality observed among these fish. Comparisons of population and individual growth rates revealed that smaller fish of age-classes 1 to 5 suffer higher mortality than do the larger individuals of these age-classes, implicating mortality agents other than those related to spawning. We provide evidence to support the hypothesis that the most probable cause of mortality is size-related differential exposure to toxic stress whereby small brook trout (< 25 cm) are found in lake areas (brooks) exhibiting the most potentially toxic combination of pH and aluminum, thus enhancing the exposure of the most susceptible part of the population to toxic stress. Large brook trout [Formula: see text] are found in the "safest" lake areas (springs), thus diminishing the exposure of the least susceptible part of the population to toxic stress and enhancing survival. Female trout exhibit delayed sexual maturity relative to other Quebec populations, attaining 50% maturity at age 3 and a length of 21–24 cm such that the major part of the population's reproductive effort is provided by those fish representing only 15% of the population in 1979 and 1980. During the October spawning season, 20% of potential spawners exhibited retarded oogenesis. These reductions in reproductive effort and changes in spawning site selection provide evidence in support of the hypothesis that recruitment failure may be occurring in the Tantaré brook trout population.

Prevalence and abundance of helminth parasites in an intensively fished population of brook trout (Salvelinus fontinalis) at a small subarctic lake

1991 ◽  
Vol 69 (3) ◽  
pp. 691-697 ◽  
Author(s):  
E. Albert ◽  
M. A. Curtis
Keyword(s):  
Brook Trout ◽  
Fish Population ◽  
First Year ◽  
Helminth Parasites ◽  
Trout Population ◽  
Gill Net ◽  
Residual Stock ◽  
Fish Catch ◽  
Capita Food ◽  
Second Year

Brook trout from a 5-ha lake near Schefferville, Quebec, were intensively sampled by small-mesh gill nets during 2 successive years to study patterns of helminth parasite occurrence in relation to changes in the age and size class structure of the fish population. Nearly 1800 brook trout were removed from the lake, of which all were measured and weighed, 568 were aged by otolith readings, and 361 were examined for parasites. The digeneans Crepidostomum farionis, Phyllodistomum umblae, and Diplostomum sp. and the cestode Eubothrium salvelini were present in more than 50% of the necropsied fish, and the prevalence and (or) abundance of all species except C. farionis increased from the first to the second year of the study. The fish catch in the first year was dominated by the 3+ year class and older fish, whereas by the second year 1+ and 2+ fish were proportionately more abundant, and the importance of older cohorts declined. This change in brook trout population structure, resulting from gill net selectivity, appears to have had the effect of improving per capita food availability for members of the residual stock. After the initial year of intensive fishing, the fish that remained fed more upon both benthic and planktonic invertebrates and their acquisition of parasites was intensified.

Rate of growth, mature weight and life-span

1962 ◽  
Vol 156 (962) ◽  
pp. 96-108 ◽  
Keyword(s):  
Kidney Disease ◽  
Life Span ◽  
Early Growth ◽  
First Year ◽  
Fast Growing ◽  
Growing Rats ◽  
Large Numbers ◽  
Lung Infections ◽  
First Year Of Life ◽  
Slow Growing

Rats which were suckled in large numbers to retard their early growth continued to grow slowly even when they were supplied with unlimited food after weaning, and they became small adults. They lived on the average for about the same length of time as much larger rats which had originally been suckled in small numbers to ensure their unrestricted growth. There was a higher mortality among the slow-growing rats in the first year of life but the effect of this was compensated in the slow-growing females by an increase in life-span among those which survived the first year. No such increase was observed in the surviving slow-growing males, and the slow-growing males as a whole had an appreciably shorter expectation of life than the fast-growing ones. The incidence of lung infections was higher in the slow-growing animals; of kidney disease and of tumours in the fast-growing ones. Kidney disease was more common in males and tumours in females. These findings do not support the view that nutritionally retarded growth necessarily promotes longevity, or that it might increase the life-span of a community.

Escalated aggression in interpopulation brook trout dyads: evidence for behavioural divergence

2003 ◽  
Vol 81 (5) ◽  
pp. 911-915 ◽  
Author(s):  
Robert Dunbrack ◽  
Lynn Clarke
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Low Cost ◽  
Isolated Populations ◽  
Communication Failure ◽  
Behavioural Assessment ◽  
Different Populations ◽  
The Cost ◽  
Population Norm

The "communication-failure" hypothesis states that individuals whose agonistic displays deviate from the population norm are selected against because of the greater likelihood of their becoming involved in escalated contests. A corollary of this hypothesis is that the level of aggression in dyadic (pairwise) contests over resources is predicted to be higher the greater the behavioural divergence between the two contestants. Display divergence between two contestants from different populations should exceed that in intrapopulation dyads, consequently this prediction can be tested by comparing levels of aggression in contests between interpopulation dyads with those in contests between intra population dyads. We carried out such a test using brook trout (Salvelinus fontinalis) from two isolated populations in eastern Newfoundland. In initial encounters, the nipping rate (a measure of aggressiveness) of individuals from one of these populations was significantly higher in interpopulation dyads than in intrapopulation dyads. These results are consistent with the communication-failure hypothesis, as well as with the view that behavioural assessment, using low-cost stereotypic displays, reduces the cost of interactions over resources for both contestants.

Sign in / Sign up

Export Citation Format

Share Document