Shifts in the Diets of Slimy Sculpin ( Cottus cognatus ) and Lake Whitefish ( Coregonus clupeaformis ) in Lake Ontario Following the Collapse of the Burrowing Amphipod Diporeia

2003 ◽  
Vol 6 (3) ◽  
pp. 311-323 ◽  
Author(s):  
Randall W. Owens ◽  
Dawn E. Dittman
2018 ◽  
Vol 75 (8) ◽  
pp. 1329-1336 ◽  
Author(s):  
Ellen M. George ◽  
Matthew P. Hare ◽  
Darran L. Crabtree ◽  
Brian F. Lantry ◽  
Lars G. Rudstam

Cisco (Coregonus artedi) are an important component of native food webs in the Great Lakes, and their restoration is instrumental to the recovery of lake trout (Salvelinus namaycush) and Atlantic salmon (Salmo salar). Difficulties with visual identification of larvae can confound early life history surveys, as cisco are often difficult to distinguish from lake whitefish (Coregonus clupeaformis). We compared traditional visual species identification methods with genetic identifications based on barcoding of the mitochondrial cytochrome c oxidase I gene for 726 coregonine larvae caught in Chaumont Bay, Lake Ontario. We found little agreement between the visual characteristics of cisco identified by genetic barcoding and the most widely used dichotomous key, and the considerable overlap in ranges of traditionally utilized metrics suggests that visual identification of coregonine larvae from Chaumont Bay is impractical. Coregonines are highly variable and plastic species and often display wide variations in morphometric characteristics across their broad range. This study highlights the importance of developing accurate, geographically appropriate larval identification methods to best inform cisco restoration and management efforts.


2017 ◽  
Vol 69 ◽  
pp. 294-301 ◽  
Author(s):  
Lindy M. Whitehouse ◽  
Chance S. McDougall ◽  
Daniel I. Stefanovic ◽  
Douglas R. Boreham ◽  
Christopher M. Somers ◽  
...  

1975 ◽  
Vol 32 (3) ◽  
pp. 404-407 ◽  
Author(s):  
M. C. Healey ◽  
C. W. Nicol

We found no significant differences in slope or intercept for the regression of loge fecundity on loge fork length among samples of whitefish from four lakes near Yellowknife in the Northwest Territories. The equation describing the relationship between fecundity and fork length for these populations was:[Formula: see text]Five other populations for which length–fecundity relationships could be calculated had length exponents ranging from 3.20 to 4.38, suggesting a nonlinear relationship between weight and fecundity. Six of the nine populations as well as four others for which limited data were available all had similar relative fecundities. Fish from Buck Lake in Alberta and from Lake Erie had high relative fecundities while fish from Great Slave Lake had low relative fecundity.


1985 ◽  
Vol 63 (2) ◽  
pp. 396-399 ◽  
Author(s):  
Hilda Lei Ching

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.


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