Biochemical Genetic Differentiation of Lake Trout (Salvelinus namaycush) Stocks of the Great Lakes Region

1988 ◽  
Vol 45 (6) ◽  
pp. 1018-1029 ◽  
Author(s):  
P. E. Ihssen ◽  
J. M. Casselman ◽  
G. W. Martin ◽  
R. B. Phillips
Keyword(s):  
Genetic Variability ◽  
Great Lakes ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Significant Degree ◽  
Allelic Frequency ◽  
Small Lakes ◽  
Large Lakes ◽  
Geographic Ranges ◽  
Allelic Frequencies

Allelic frequencies for lake trout (Salvelinus namaycush) samples collected from 27 small lakes or spawning shoals on larger lakes did not show significant annual changes. Levels of genetic variability were in the high range for Salmonidae, with 57% of the loci examined polymorphic (1% criterion) and 4.7% average heterozygosity per locus. Twenty-one percent of the total genetic variability was due to differences between stocks. Highly significant allelic frequency differences were found among allopatric as well as sympatric stocks. Genetic differences among sympatric stocks of Lake Superior indicated a significant degree of genetic isolation among these stocks. Genetic diversity within stocks, as measured by the proportion of polymorphic loci, was larger in stocks from large lakes than small lakes or transplanted stocks from large lakes into small lakes. Geographic patterns in allelic frequencies were observed. Samples from the northwestern range of our study area (upper Great Lakes, northwestern Ontario, and Manitoba) could be distinguished from those of the southeastern range by both allelic frequency differences and the presence or absence of alleles. We suggest that these two geographic ranges were colonized by lake trout that survived in different refugia during the Wisconsin glaciation. Unusual stocks of lake trout were found in three small lakes in the Haliburton Highlands of southern Ontario, with alleles at high frequencies that are rare or absent in most other stocks. We propose that the Haliburton Highlands lake trout originated from a glacial relict stock and survived during the last glaciation isolated from refugia used by other lake trout.

Classification of Sea Lamprey (Petromyzon marinus) Attack Marks on Great Lakes Lake Trout (Salvelinus namaycush)

1980 ◽  
Vol 37 (11) ◽  
pp. 1989-2006 ◽  
Author(s):  
Everett Louis King Jr.
Keyword(s):  
Great Lakes ◽  
Lake Trout ◽  
Petromyzon Marinus ◽  
Attachment Site ◽  
Sea Lamprey ◽  
Salvelinus Namaycush ◽  
Oral Disc ◽  
Field Assessment ◽  
Sea Lampreys

Criteria for the classification of marks inflicted by sea lamprey (Petromyzon marinus) into nine categories were developed from laboratory studies in an attempt to refine the classification system used in field assessment work. These criteria were based on characteristics of the attachment site that could be identified under field conditions by unaided visual means and by touching the attachment site. Healing of these marks was somewhat variable and was influenced by the size of lamprey, duration of attachment, severity of the wound at lamprey detachment, season and water temperature, and by other less obvious factors. Even under laboratory conditions staging of some wounds was difficult, especially at low water temperatures. If these criteria are to be used effectively and with precision in the field, close examination of individual fish may be required. If the feeding and density of specific year-classes of sea lampreys are to be accurately assessed on an annual basis, close attention to the wound size (as it reflects the size of the lamprey's oral disc) and character of wounds on fish will be required as well as consideration of the season of the year in which they are observed.Key words: sea lamprey, attack marks, lake trout, Great Lakes

Effects of coancestry on accuracy of individual assignments to population of origin: examples using Great Lakes lake trout (Salvelinus namaycush)

Genetica ◽  
2006 ◽  
Vol 127 (1-3) ◽  
pp. 329-340 ◽  
Author(s):  
Bruno Guinand ◽  
Kim T. Scribner ◽  
Kevin S. Page ◽  
Kristi Filcek ◽  
Laura Main ◽  
...  
Keyword(s):  
Great Lakes ◽  
Lake Trout ◽  
Salvelinus Namaycush

Responses of Lake Trout (Salvelinus namaycush) to Harvesting, Stocking, and Lamprey Reduction

1980 ◽  
Vol 37 (11) ◽  
pp. 2133-2145 ◽  
Author(s):  
Carl J. Walters ◽  
Greg Steer ◽  
George Spangler
Keyword(s):  
Simple Model ◽  
Policy Analysis ◽  
Great Lakes ◽  
Population Regulation ◽  
Lake Trout ◽  
Normal Population ◽  
Lake Superior ◽  
Sea Lamprey ◽  
Salvelinus Namaycush ◽  
Density Dependent

Sustained yields, declines, and recovery of lake trout (Salvelinus namaycush) can be explained by a simple model that hypothesizes normal population regulation through density dependent body growth, coupled with depensatory lamprey mortality. The model indicates that either lamprey or fishing alone could have caused the Lake Superior decline, though they apparently operated in concert. The presence of depensatory lamprey mortality leads to a "cliff edge" in the system's dynamics, such that catastrophic changes may be repeated in the future. It is not unlikely that Lake Superior is on the verge of a second collapse. Options for dealing with potential disasters include conservative harvesting policies, development of more sensitive monitoring indicators, and modified stocking policies that may speed the coevolution of a viable lamprey/trout association.Key words: lake trout, sea lamprey, simulation, Great Lakes, policy analysis

Paenibacillus thiaminolyticus is not the cause of thiamine deficiency impeding lake trout (Salvelinus namaycush) recruitment in the Great Lakes

2012 ◽  
Vol 69 (6) ◽  
pp. 1056-1064 ◽  
Author(s):  
Catherine A. Richter ◽  
Allison N. Evans ◽  
Maureen K. Wright-Osment ◽  
James L. Zajicek ◽  
Scott A. Heppell ◽  
...  
Keyword(s):  
Great Lakes ◽  
Thiamine Deficiency ◽  
Lake Trout ◽  
Bacterial Species ◽  
Primary Source ◽  
Salvelinus Namaycush ◽  
Trophic Levels ◽  
Thiaminase I ◽  
Global Concern ◽  
Paenibacillus Thiaminolyticus

Thiamine (vitamin B1) deficiency is a global concern affecting wildlife, livestock, and humans. In Great Lakes salmonines, thiamine deficiency causes embryo mortality and is an impediment to restoration of native lake trout ( Salvelinus namaycush ) stocks. Thiamine deficiency in fish may result from a diet of prey with high levels of thiaminase I. The discoveries that the bacterial species Paenibacillus thiaminolyticus produces thiaminase I, is found in viscera of thiaminase-containing prey fish, and causes mortality when fed to lake trout in the laboratory provided circumstantial evidence implicating P. thiaminolyticus. This study quantified the contribution of P. thiaminolyticus to the total thiaminase I activity in multiple trophic levels of Great Lakes food webs. Unexpectedly, no relationship between thiaminase activity and either the amount of P. thiaminolyticus thiaminase I protein or the abundance of P. thiaminolyticus cells was found. These results demonstrate that P. thiaminolyticus is not the primary source of thiaminase activity affecting Great Lakes salmonines and calls into question the long-standing assumption that P. thiaminolyticus is the source of thiaminase in other wild and domestic animals.

New insight into the spawning behavior of lake trout, Salvelinus namaycush, from a recovering population in the Laurentian Great Lakes

2014 ◽  
Vol 98 (1) ◽  
pp. 173-181 ◽  
Author(s):  
T. R. Binder ◽  
H. T. Thompson ◽  
A. M. Muir ◽  
S. C. Riley ◽  
J. E. Marsden ◽  
...  
Keyword(s):  
Great Lakes ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Laurentian Great Lakes ◽  
Spawning Behavior ◽  
Insight Into

Pelagic distribution of lake trout (Salvelinus namaycush) in small Canadian Shield lakes with respect to temperature, dissolved oxygen, and light

1998 ◽  
Vol 55 (1) ◽  
pp. 170-179 ◽  
Author(s):  
Todd J Sellers ◽  
Brian R Parker ◽  
David W Schindler ◽  
William M Tonn
Keyword(s):  
Light Intensity ◽  
Dissolved Oxygen ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Canadian Shield ◽  
Small Lakes ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Oxygenated Water ◽  
Shield Lakes

The distribution of lake trout (Salvelinus namaycush) with respect to water temperature, dissolved oxygen, and light intensity was surveyed in three small Canadian Shield lakes at the Experimental Lakes Area, northwestern Ontario. Based on hydroacoustic and gillnet surveys, there was considerable variation among lakes in temperatures occupied by lake trout during the summer. During the day, lake trout were concentrated at 4-8°C in Lake 375, broadly distributed from 6 to 15°C in Lake 442, and concentrated in the epilimnion at 19°C in Lake 468. At night, lake trout in all lakes occupied epilimnetic waters at 19-20°C. Lake trout inhabited highly oxygenated water, with 75-90% of fish at >6 mg dissolved oxygen ·L-1 throughout the spring and summer in all three lakes. Light intensity did not affect lake trout distribution in Lake 468 but may have contributed to lake trout daytime descent into cool waters in Lakes 375 and 442. We suggest that previously assumed niche boundaries of lake trout do not adequately describe critical habitat for the species in small lakes, the same lakes that are likely most sensitive to erosion of such habitat.

Taxonomy of a Swimbladder Nematode, Cystidicola stigmatura (Leidy), and Evidence of its Decline in the Great Lakes

1983 ◽  
Vol 40 (5) ◽  
pp. 643-647 ◽  
Author(s):  
Geoff A. Black
Keyword(s):  
Great Lakes ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Valid Species ◽  
Museum Specimens

Cystidicola stigmatura (Leidy, 1886) Ward and Magath, 1917 is considered a valid species after examination of specimens from Leidy's collection. Cystidicola cristivomeri White, 1941 is considered a synonym of C. stigmatura. Cystidicola stigmatura is distinguished from the only other species in the genus, namely C. farionis Fischer, 1798, by the presence of lateral lobes on the eggs rather than filaments. A neotype of F. stigmatura is designated. Cystidicola stigmatura has not been found in fishes in the Great Lakes since 1925. The parasite was found in museum specimens of lake trout (Salvelinus namaycush) collected before 1925, suggesting that the species became rare or disappeared with the decline of lake trout in these lakes.

Allozyme Variation of Great Lakes Alewife, Alosa pseudoharengus: Genetic Differentiation and Affinities of a Recent Invader

1992 ◽  
Vol 49 (9) ◽  
pp. 1770-1777 ◽  
Author(s):  
Peter E. Ihssen ◽  
G. William Martin ◽  
David W. Rodgers
Keyword(s):  
New York ◽  
Great Lakes ◽  
Allozyme Variation ◽  
Allelic Frequency ◽  
Starch Gel Electrophoresis ◽  
Alosa Pseudoharengus ◽  
Allelic Frequencies ◽  
Cayuga Lake ◽  
Finger Lakes ◽  
Allozyme Loci

Allelic frequencies for six polymorphic allozyme loci (27 loci examined), as determined by starch-gel electrophoresis, were not significantly different for alewife, Alosa pseudoharengus, among the Great Lakes (Ontario, Erie, Huron, and Michigan). Alewife from one of the Finger Lakes (Cayuga Lake) had allelic frequencies similar to Great Lakes alewife, and the alleles of Great Lakes alewife form a subset of those found in Cayuga Lake. In contrast, Maritime Canada populations (Gaspereau, Miramichi, and St. John rivers) were distinct from each other and from the Great Lakes and Cayuga Lake populations. Highly significant allelic frequency differences were observed among the Maritime populations and between the Maritime populations and the Great Lakes or Cayuga Lake populations. Fifteen alleles were not shared between the Great Lakes and the Maritime populations. We concluded from these results that Great Lakes alewife and Cayuga Lake alewife form a contiguous stock and that Great Lakes alewife are a recent invader that probably originated from the Hudson–Mohawk rivers via the Erie Canal and the New York Finger Lakes rather than the previously suggested alternative origin from the Canadian Maritimes via the St. Lawrence River.

Hydroxylated PCBs and Other Chlorinated Phenolic Compounds in Lake Trout (Salvelinus namaycush) Blood Plasma from the Great Lakes Region

2003 ◽  
Vol 37 (9) ◽  
pp. 1720-1725 ◽  
Author(s):  
Linda M. Campbell ◽  
Derek C. G. Muir ◽  
D. Mike Whittle ◽  
Sean Backus ◽  
Ross J. Norstrom ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Great Lakes ◽  
Blood Plasma ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Great Lakes Region ◽  
Hydroxylated Pcbs ◽  
Chlorinated Phenolic Compounds
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