THE FIRST FILLING OF THE SWIM BLADDER IN SALMONOIDS

1960 ◽  
Vol 38 (1) ◽  
pp. 179-187 ◽  
Author(s):  
J. S. Tait
Keyword(s):  
Deep Water ◽  
Salmo Trutta ◽  
Lake Trout ◽  
Swim Bladder ◽  
Coregonus Clupeaformis ◽  
Relative Ease

Salmo trutta, S. gairdneri, Cristivomer namaycush, and Coregonus clupeaformis failed to fill their swim bladders while being reared without access to an air surface for 84, 50, 22, and 56 weeks after hatching, respectively. When given access to an air surface they filled them. It is concluded that, like other physostomes, they must swallow air for the initial filling, but even if filling is delayed their pneumatic ducts remain open. In control trout, filling occurred at the beginning of feeding, and in whitefish controls, 2 to 3 months after hatching (at 20–22 mm length). Lake trout fry with unfilled swim bladders swam up vertical distances ranging up to 900 ft without marked fatigue, indicating that fish hatched in deep water can swim to the surface with relative ease to fill their swim bladders.

Migration and development of swim-bladder nematodes, Cystidicola spp. (Habronematoidea), in their definitive hosts

1980 ◽  
Vol 58 (11) ◽  
pp. 1997-2005 ◽  
Author(s):  
Geoff A. Black ◽  
Murray W. Lankester
Keyword(s):  
Rainbow Trout ◽  
Lake Trout ◽  
Distinct Species ◽  
Salmo Gairdneri ◽  
Swim Bladder ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Northwestern Ontario ◽  
Third Stage ◽  
Migration And Development

Third-stage larvae of Cystidicola cristivomeri White, 1941, and C. farionis Fischer, 1798, migrated directly via the pneumatic duct to the swim bladder of lake trout, Salvelinus namaycush, and rainbow trout, Salmo gairdneri, respectively. Larvae reached the swim bladder as early as 16 h after fish were infected using a stomach tube. At 4–10 °C, mature male and female C. cristivomeri and C. farionis were first recovered 67 and 210 days, and 112 and 235 days, respectively, after infection. Cystidicola cristivomeri is probably long-lived; there was no evidence that any died in lake trout infected for up to 600 days.Large numbers of third-stage cystidicolid larvae accumulated without maturing in the swim bladder of naturally infected lake whitefish, Coregonus clupeaformis, from Lake Nipigon, northwestern Ontario. When given to rainbow trout, these larvae matured and the adult nematodes were identical to C. farionis. These results suggest that the swim-bladder nematode that matures in lake whitefish is a distinct species.

An examination of the PCB: lipid relationship among individual fish

1997 ◽  
Vol 54 (5) ◽  
pp. 1031-1038
Author(s):  
C A Stow ◽  
L J Jackson ◽  
J F Amrhein
Keyword(s):  
Salmo Trutta ◽  
Lake Michigan ◽  
Oncorhynchus Tshawytscha ◽  
Lake Trout ◽  
Coho Salmon ◽  
Salvelinus Namaycush ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Strong Linear Correlation ◽  
Brown Trout Salmo Trutta ◽  
The Relationship

We examined data from 1984 to 1994 for five species of Lake Michigan salmonids to explore the relationship between total PCB concentration and percent lipid. When we compared mean species lipid and PCB values, we found a strong linear correlation. When we compared values among individuals, we found modest positive PCB:lipid associations in brown trout (Salmo trutta), chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), and rainbow trout (Oncorhynchus mykiss) collected during spawning, but positive associations were not apparent among nonspawning individuals. Lake trout (Salvelinus namaycush) exhibited no discernible PCB:lipid relationship. Our results are not incompatible with previous observations that contaminants are differentially partitioned into lipids within a fish, but these results do suggest that lipids are not a major factor influencing contaminant uptake.

Occurrence of the eyefluke, Diplostomum (Diplostomum) baeri bucculentum Dubois et Rausch, 1948, in salmonid fishes of northern British Columbia

1985 ◽  
Vol 63 (2) ◽  
pp. 396-399 ◽  
Author(s):  
Hilda Lei Ching
Keyword(s):  
Rainbow Trout ◽  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Lake Trout ◽  
Infected Fish ◽  
Salmo Gairdneri ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Dolly Varden Salvelinus Malma ◽  
Prosopium Williamsoni

As a result of experimental infections in chicks, diplostomula found in the retina of chinook salmon from the Nechako River were identified as Diplostomum (Diplostomum) baeri bucculentum. Eyeflukes in other salmonids were considered to be the same species based on similar measurements and site in the eyes. These eyeflukes varied in prevalence and mean intensity in seven salmonid species surveyed in nine localities in 1979–1981. The following fish were sampled: rainbow trout (Salmo gairdneri), 505; mountain whitefish (Prosopium williamsoni), 334; lake whitefish (Coregonus clupeaformis), 32; Dolly Varden (Salvelinus malma), 66; lake trout (S. namaycush), 13; kokanee or sockeye salmon (Oncorhynchus nerka), 323; and chinook salmon (O. tshawytscha), 164. Eyeflukes had prevalences ranging from 84 to 100% in six lakes, 64% in the river, 53% in one reservoir site, and a prevalence of 15% in the other reservoir site. Mountain and lake whitefishes had high mean intensities while kokanee had low mean intensities. Correlation of increased intensity with increased fish size was significant for 6 of 27 samples. Four samples of lake whitefish, mountain whitefish, rainbow trout, and chinook salmon showed significant asymmetry when numbers of diplostomula were compared between eyes. More of the heavily infected fish showed asymmetry than did the lightly infected fish.

Changes in fish populations affected by the construction of the La Grande complex (Phase I), James Bay region, Quebec

1995 ◽  
Vol 73 (10) ◽  
pp. 1860-1877 ◽  
Author(s):  
Jean-Claude DesLandes ◽  
Sylvie Guénette ◽  
Yves Prairie ◽  
Réjean Fortin ◽  
Dominique Roy ◽  
...  
Keyword(s):  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Time Intervals ◽  
Complex Phase ◽  
Coregonus Artedii ◽  
Secondary Productivity ◽  
Longnose Sucker ◽  
The Impact

Catches per unit of effort (CPUE) with experimental gill nets, recruitment, growth, and condition were monitored between 1977 and 1992 to evaluate the impact of impoundment on the main fish species of La Grande 2, Opinaca, and Caniapiscau reservoirs and the Boyd–Sakami diversion. CPUE and recruitment of northern pike (Esox lucius) and lake whitefish (Coregonus clupeaformis) increased markedly at most stations after impoundment and decreased at the end of the series. The lake whitefish and cisco (Coregonus artedii) showed their most striking rise in CPUE at two bay stations of La Grande 2 and Opinaca reservoirs. CPUE and recruitment of the longnose sucker (Catostomus catostomus), white sucker (Catostomus commersoni), and lake trout (Salvelinus namaycush) (Caniapiscau) showed a general decrease following impoundment. CPUE for the walleye (Stizostedion vitreum) also decreased at several stations; however, the two most southerly stations in La Grande 2 reservoir and the Boyd–Sakami station showed high CPUE during the series. Concentration–redistribution phenomena explain part of the observed variations in CPUE. Correlation analyses showed that walleyes and white suckers were attracted to the warmer, more turbid stations, and that the high primary and secondary productivity of bay stations attracted the coregonines. Growth and condition of the main species increased during variable time intervals after impoundment and decreased at the end of the series.

Fecundity Changes in Exploited Populations of Lake Whitefish (Coregonus clupeaformis) and Lake Trout (Salvelinus namaycush)

1978 ◽  
Vol 35 (7) ◽  
pp. 945-950 ◽  
Author(s):  
M. C. Healey
Keyword(s):  
Key Words ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Northern Canada ◽  
Average Fecundity ◽  
Individual Fecundity

This report considers the possibility that exploited populations of lake whitefish (Coregonus clupeaformis) and lake trout (Salvelinus namaycush) may show increased individual fecundity. Average fecundity of both species in three exploited lakes varied significantly between 1972 and 1976, while fecundity in an adjacent unexploited lake did not vary. Changes in the fecundity of whitefish and trout in the exploited lakes were not clearly related to the pattern and intensity of exploitation, but fecundity of both species increased in all exploited lakes after exploitation, with trout showing the greater response. Key words: fecundity, lake whitefish, lake trout, exploitation, northern Canada

Polychlorinated Biphenyls and Polychlorinated Dioxins–Furans in Lake Trout and Whitefish Composite Samples from Commercial Fisheries in Lakes Erie, Huron, and Superior

2017 ◽  
Vol 80 (8) ◽  
pp. 1228-1238 ◽  
Author(s):  
Dorothea F. K. Rawn ◽  
Michael Dowd ◽  
Matthew J. S. Scuby ◽  
Peter P. Pantazopoulos ◽  
Mark Feeley
Keyword(s):  
Polychlorinated Biphenyls ◽  
Lake Trout ◽  
Lake Huron ◽  
Coregonus Clupeaformis ◽  
Spearman Correlation ◽  
Toxic Equivalent ◽  
Time Period ◽  
Commercially Important ◽  
Insight Into ◽  
Composite Samples

ABSTRACT Polychlorinated biphenyls (PCBs; sum of 36 congeners) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs; sum of 17 2,3,7,8-substituted congeners) were measured in 93 composite samples prepared from individual lake trout (Salvelinus namaycush) and whitefish (Coregonus clupeaformis) samples collected from Lake Erie, Lake Huron, and Lake Superior. All samples had detectable concentrations of PCBs and PCDD/Fs; maximum PCB concentrations in both trout (750 ng g−1 whole weight [ww]) and whitefish (210 ng g−1 ww) were found in composites from fish collected from Lake Huron. The maximum toxic equivalent concentration was found in a lake trout composite sample from Lake Huron (53 pg g−1 ww). PCB and PCDD/F congener profiles were comparable to patterns observed in fishes collected from other regions of Canada, although concentrations were above those found in other regions. A positive correlation was found between PCB concentrations determined using the historical Aroclor equivalency method and those determined using the sum of the congeners measured (r2 = 0.871; Spearman correlation r = 0.917) or using the six indicator PCB congeners (28, 52, 101, 138, 153, and 180; r2 = 0.850; Spearman correlation r = 0.935). PCBs were the dominant contributor to the overall toxic equivalent concentrations in the fish composite samples tested. These findings provide insight into PCB and PCDD/F concentrations in two commercially important fish species over a discrete time period.

Long-Term Effects of Diet on the Biology of the Lake Trout and the Fishery in Lake Opeongo, Ontario

1970 ◽  
Vol 27 (1) ◽  
pp. 125-146 ◽  
Author(s):  
N. V. Martin
Keyword(s):  
Lake Trout ◽  
Feeding Activity ◽  
Salvelinus Namaycush ◽  
Point Of View ◽  
Average Weight ◽  
Coregonus Clupeaformis ◽  
Long Term Effects ◽  
Food Content ◽  
Coregonus Artedii

From 1936 to 1965 food content was examined in 17,171 Lake Opeongo lake trout (Salvelinus namaycush). The diet is analysed from the point of view of frequency of occurrence of foods, their weight, feeding activity of trout, size of trout and size of food, and seasonal and annual changes in food habits.In the late 1940's and early 1950's perch, Perca flavescens, largely disappeared from the diet. The lake trout initially turned to lake whitefish, Coregonus clupeaformis, and then to the cisco, Coregonus artedii, introduced into Lake Opeongo in 1948.As a result of these dietary changes lake trout are now heavier and rate of growth has improved. Age and size at maturity is later and there are fewer infertile fish. Egg counts, egg size, and ovary weights are now greater, particularly in the medium-sized lake trout.In the fishery the average weight of individual trout taken has almost doubled. About 25% more of the immature stock is exploited by the recent fishery. The harvest and catchability of lake trout has remained generally constant on a numerical basis but show an improvement on a poundage basis in the more recent years. The possible effects of these changes on the character of the fishery are discussed.

STUDIES ON CESTODES OF THE GENUS TRIAENOPHORUS FROM FISH OF LESSER SLAVE LAKE, ALBERTA: IV. THE LIFE OF TRIAENOPHORUS CRASSUS FOREL IN THE SECOND INTERMEDIATE HOST

1945 ◽  
Vol 23d (4) ◽  
pp. 105-115 ◽  
Author(s):  
Richard B. Miller
Keyword(s):  
Intermediate Host ◽  
Lake Trout ◽  
Body Cavity ◽  
The Body ◽  
Coregonus Clupeaformis ◽  
Alternative Hosts ◽  
Pyloric Caeca ◽  
Drying Up ◽  
Second Intermediate Host

The plerocercoids of Triaenophorus crassus encyst normally in the flesh of fishes of the genus Leucichthys; the whitefishes, Coregonus clupeaformis and Prosopium oregonium, are common alternative hosts in Lesser Slave Lake. Elsewhere lake trout, Cristivomer namaycush, and possibly the inconnu, Stenodus leucichthys, may occasionally serve as hosts.The procercoids arrive in the stomach of their second intermediate host while in the body cavity of Cyclops bicuspidatus. When they are liberated by digestion, the majority apparently enter pyloric caeca, penetrate these, cross the body cavity, and enter the flesh, where encystment as the plerocercoid takes place. The evidence for these movements is only partial. The plerocercoids encyst in the flesh in July each year. They remain three or four years and then disappear by drying up or being reduced to small calcareous nodules.The number of plerocercoids per fish increases with the age of the fish up to five or six years.

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