Genetic Differences in Retention of Swimbladder Gas Between Two Populations of Lake Trout (Salvelinus namaycush)

1974 ◽  
Vol 31 (8) ◽  
pp. 1351-1354 ◽  
Author(s):  
P. Ihssen ◽  
J. S. Tait
Keyword(s):  
Brook Trout ◽  
Depth Distribution ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Genetic Differences ◽  
Trout Population ◽  
Two Populations

Lake trout (Salvelinus namaycush) derived from two populations differed in retention of swimbladder gas. The two reciprocal interpopulation crosses were intermediate to the parent populations. The two F1 hybrids obtained by crossing fish from each lake trout population with brook trout (S. fontinalis) were also found different in retention. Gas retention was correlated with depth distribution of the parent populations, high retention being associated with deeper distribution.

Predation by Freshwater Seals on the Fish Community of Lower Seal Lake, Quebec

1978 ◽  
Vol 35 (6) ◽  
pp. 844-850 ◽  
Author(s):  
G. Power ◽  
Jean Gregoire
Keyword(s):  
Brook Trout ◽  
Fish Community ◽  
Lake Trout ◽  
Fork Length ◽  
Salvelinus Namaycush ◽  
Phoca Vitulina ◽  
Unit Weight ◽  
Potential Yield ◽  
Spawning Period ◽  
Show Evidence

The presence of freshwater harbor seals (Phoca vitulina) in Lower Seal Lake, Quebec, has drastically modified the lake's fish community. Lake trout (Salvelinus namaycush) are the most affected; they are small (rarely exceed 55 cm fork length), their growth rate is faster than in neighboring lakes, their longevity is greatly reduced, the age at sexual maturity has been halved, and individual fecundity per unit weight has increased at the expense of egg diameter. Brook trout (S. fontinalis), the dominant fish species in the lake, show evidence of high mortality rates in the lake, but are protected during the vulnerable spawning period because their spawning sites are dispersed in tributary streams. Rough calculation suggests the seal population is small and that it consumes the lake's potential yield of fish annually. Key words: predation, freshwater seals, Phoca vitulina, Salvelinus namaycush, Salvelinus fontinalis

Recovery of Planted Brook Trout, Splake, and Rainbow Trout from Selected Ontario Lakes

1972 ◽  
Vol 29 (2) ◽  
pp. 129-142 ◽  
Author(s):  
J. M. Fraser
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Fish Community ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Low Fertility ◽  
Salmo Gairdneri ◽  
White Sucker ◽  
The Mean ◽  
Brook Stickleback

Recoveries of hatchery-reared brook trout (Salvelinus fontinalis), splake (Salvelinus namaycush × S. fontinalis), and rainbow trout (Salmo gairdneri), planted in lakes having different resident fishes, were highest (9–30%) in a lake in which minnows and the brook stickleback were the only other fishes. Recoveries, by angling and gillnetting, were considerably lower (2–15%) in two lakes containing the white sucker and minnows, and still lower (0.5–5%,) in two lakes containing spiny-rayed species as well. Recoveries were lowest (< 0.5%) in a lake having a complex fish community that included native brook and lake trout. Planted splake and rainbow trout generally yielded higher returns, in weight, than brook trout in comparable situations.The low survival of planted fish was apparently due to the low fertility of the waters and to competition with, or predation by, resident fish species. Predation by fish-eating birds and mammals may also have had an effect.The weight of the catch of salmonids exceeded the weight planted in only one lake. Here, the mean yield of planted salmonids was 8.4 kg/ha per year in comparison with 2.6 to < 0.5 kg/ha per year in the five other study lakes.

Effects of forestry roads on reproductive habitat and exploitation of lake trout (Salvelinus namaycush) in three experimental lakes

2000 ◽  
Vol 57 (S2) ◽  
pp. 97-104 ◽  
Author(s):  
John M Gunn ◽  
Rod Sein
Keyword(s):  
Lake Trout ◽  
Natural Populations ◽  
Fork Length ◽  
Salvelinus Namaycush ◽  
Spawning Habitat ◽  
Trout Population ◽  
Access Road ◽  
Short Term Study ◽  
Opaque Plastic ◽  
Spawning Sites

This study was designed to test the effects of two potential impacts of forest access roads on lake trout (Salvelinus namaycush) lakes in the Boreal Shield ecozone: (i) loss of reproductive habitat through siltation and (ii) increased access and exploitation. During an 9-year study (1991-1999) in Whitepine Lake, access to seven original spawning sites and over 250 alternate spawning sites was progressively removed by covering the substrate with opaque plastic sheeting to simulate siltation. No effects on recruitment of lake trout have yet been detected. Mark-recapture estimates of juvenile (<370 mm fork length) abundance remained high, mean body size did not increase, and emergent alevins continued to be produced from the alternate spawning sites each year. Similar results occurred in a short-term study in Helen Lake. The lack of obvious effects of reproductive habitat loss was in sharp contrast with the rapid and severe effects that fishing pressure exerted on the lake trout population in Michaud Lake where access was improved by construction of a 12-km forest access road. These findings suggest that lake trout can tolerate substantial losses in spawning habitat, but natural populations, particularly in small lakes, must be protected from excessive exploitation.

Joint Segregation of Biochemical Loci in Salmonidae: Results from Experiments with Salvelinus and Review of the Literature on Other Species

1979 ◽  
Vol 36 (9) ◽  
pp. 1114-1128 ◽  
Author(s):  
Bernie May ◽  
James E. Wright ◽  
Mark Stoneking
Keyword(s):  
Key Words ◽  
Brook Trout ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Pairwise Comparisons ◽  
Duplicate Genes ◽  
Single Pair ◽  
Review Of The Literature ◽  
Uniform System ◽  
Joint Segregation

An extensive survey of joint segregation is described involving 37 pairwise comparisons of 12 biochemical loci in 11 single pair matings of brook trout (Salvelinus fonlinalis) and 38 pairwise comparisons of 9 loci in an F1 splake (lake trout, Salvelinus namaycush × brook trout) backcross to brook trout mating. We report pseudolinkage of two duplicated malate dehydrogenase loci (MDH-3 and MDH-4) and statistically highly significant nonrandom segregation of MDH-1 with an alphaglycerophosphate dehydrogenase locus (AGP-1). Several additional cases of aberrant joint segregation are described. All known examinations of joint segregation in Salmonidae are reviewed. A uniform system of nomenclature and guidelines for future investigations are discussed. Key words: joint segregation, brook trout, splake hybrid, inheritance, electrophoresis, pseudolinkage, duplicate-genes

Population Biology of Lake Trout (Salvelinus namaycush) of Lake Superior before 1950

1971 ◽  
Vol 28 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Gary T. Sakagawa ◽  
Richard L. Pycha
Keyword(s):  
Mortality Rate ◽  
Population Biology ◽  
Lake Trout ◽  
Lake Superior ◽  
Indirect Evidence ◽  
Total Mortality ◽  
Growth Yield ◽  
Salvelinus Namaycush ◽  
Natural Mortality ◽  
Trout Population

Scale samples collected in 1948 were used to estimate the instantaneous total mortality rate (0.70) and growth for lake trout (Salvelinus namaycush) in Lake Superior before the population had been significantly reduced by the sea lamprey (Petromyzon marinus). Indirect evidence indicates that the instantaneous natural mortality rate was probably 0.10–0.25. The Ricker model was used to calculate yield per recruitment, which varied with natural mortality and growth. Natural mortality was more critical than growth; yield per recruitment increased 183.3% with a 60% decrease in instantaneous natural mortality (from 0.25 to 0.10). For the prelamprey lake trout population the yield per recruitment was about 12–34 lb; the recruitment of about 3.6–10.1 million lake trout of age 1.5 resulted in an annual commercial production of 4 million lb.

Movement patterns and spatial segregation of two populations of lake trout Salvelinus namaycush in Lake Huron

2017 ◽  
Vol 43 (3) ◽  
pp. 108-118 ◽  
Author(s):  
Thomas R. Binder ◽  
J. Ellen Marsden ◽  
Stephen C. Riley ◽  
James E. Johnson ◽  
Nicholas S. Johnson ◽  
...  
Keyword(s):  
Lake Trout ◽  
Movement Patterns ◽  
Salvelinus Namaycush ◽  
Spatial Segregation ◽  
Lake Huron ◽  
Two Populations
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