To fast or feed: an alternative life history for anadromous brook trout Salvelinus fontinalis overwintering within a harbour

2014 ◽  
Vol 85 (3) ◽  
pp. 621-644 ◽  
Author(s):  
A. D. Spares ◽  
M. J. Dadswell ◽  
J. MacMillan ◽  
R. Madden ◽  
R. K. O'Dor ◽  
...  

2012 ◽  
Vol 69 (10) ◽  
pp. 1596-1609 ◽  
Author(s):  
Carla A.V. Serfas ◽  
Anna Varian ◽  
Rachel Holman ◽  
Lindsey M. Watch ◽  
Jesse Karner ◽  
...  

Lake Superior supports fluvial, adfluvial, and lacustrine populations of brook trout ( Salvelinus fontinalis ). Adfluvial and lacustrine populations (termed coasters) are known for their large size and are coveted by anglers; however, little is known about their migratory habits or physiology. This study examined physiology and morphology of age 1+ lacustrine, adfluvial, and fluvial strains of brook trout in a laboratory setting. All strains in the study grew; however, there were no differences in growth rate, condition, relative mass, morphology, white muscle metabolic enzymes, or gill Na+,K+-ATPase that clearly associated with putative life history strategy. Both thyroxine and triiodothyronine varied over the study period, and the fluvial (resident) strain consistently showed lower thyroid hormone levels than the three coaster strains. We conclude that the populations compared differed at the strain level, but do not show physiological or morphological variability that clearly associates with life history strategy; the exception was that populations demonstrating the coaster phenotype had increased concentrations of plasma thyroid hormones, which may be linked to growth potential or other coaster-related characteristics such as migration.



1940 ◽  
Vol 5a (2) ◽  
pp. 176-186 ◽  
Author(s):  
H. C. White

Smolts, kelts and non-mature large fish descend in May and early June to the sea, to remain feeding in the estuary or near the shore. They began (1939) to ascend the river in late June, and 93% of the "run" was in July.Fish marked when descending one branch of the river ascended both that branch and the river above but the proportion of marked fish was greater in the branch.These trout agree with the local salmon in having smolts that become silvery before migration and that are two or three years old. Trout smolts and kelts remain in the sea only about two months before returning to fresh water.



2005 ◽  
Vol 62 (4) ◽  
pp. 747-757 ◽  
Author(s):  
Pierre Magnan ◽  
Raphaël Proulx ◽  
Michel Plante

We used data from 17 populations of lacustrine brook trout (Salvelinus fontinalis) of the Canadian Shield, southern Quebec, to test whether early maturity (in males and females) and high reproductive effort (in females) are associated with increased (i) fish exploitation (sportfishing) and (ii) interspecific competition through their effects on growth and survival. The age at maturity of males and females was inversely related to the intensity of both fishing and interspecific competition. Fishing and interspecific competition affect the age at maturity through their effect on adult survival but not on growth, supporting predictions of life history models based on survival. In contrast, we did not find consistent effects of interspecific competition and fishing on the gonadosomatic index of females, which was directly related to survival (in all populations) and to the age at maturity (in exploited populations). These latter results are contrary to the predictions of life history models under the assumption that survival is directly related to growth rate. Our results suggest that reproductive effort and age at maturity are not dependent on growth when survival is independent of growth, as is the case in exploited and sympatric populations experiencing low adult survival but high growth.



2008 ◽  
Vol 65 (4) ◽  
pp. 633-644 ◽  
Author(s):  
Gunnar Öhlund ◽  
Fredrik Nordwall ◽  
Erik Degerman ◽  
Torleif Eriksson

Simple models of temperature-mediated interference competition have generally failed to explain salmonid species replacement patterns along altitudinal gradients, a fact that emphasizes the need to link individual features and their relation to habitat characteristics to population-level dynamics. We compared life history parameters in stream-resident populations of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) in eight boreal streams. By use of electrofishing data from 1000 sites, we analyzed and related differences in life history traits to habitat- and interaction-related patterns of growth and densities of brook and brown trout, respectively. Brown trout were competitively dominant throughout the size span of sampled sympatric sites and lowered growth rates in sympatry were mainly caused by environmental factors, revealing a link between brook trout invasions and habitat-related limitations on brown trout performance. Still, the frequency of allopatric brook trout sites increased in the smallest watersheds, indicating that localities with a high degree of brook trout dominance rarely sustain brown trout over time. Brook trout populations had higher turnover rates and proportions of mature females than brown trout populations. Our results suggest growth potential and its effect on population fecundity as a critical factor limiting competitive ability and distribution of brown trout in Swedish brook trout dominated headwaters.





2018 ◽  
Vol 44 (6) ◽  
pp. 1373-1382 ◽  
Author(s):  
Ashley Elias ◽  
Rob McLaughlin ◽  
Rob Mackereth ◽  
Chris Wilson ◽  
Krista M. Nichols




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