Substituting fishmeal with extruded soybean meal in diets did not affect the growth performance, hepatic enzyme activities, but hypoxia tolerance of Dolly Varden ( Salvelinus malma ) juveniles

2019 ◽  
Vol 51 (1) ◽  
pp. 379-388
Author(s):  
Fanxing Meng ◽  
Bing Li ◽  
Yuxin Xie ◽  
Ming Li ◽  
Rixin Wang
Keyword(s):  
Growth Performance ◽  
Soybean Meal ◽  
Enzyme Activities ◽  
Hypoxia Tolerance ◽  
Hepatic Enzyme ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Dolly Varden Salvelinus Malma

Fecundity of Resident and Anadromous Dolly Varden (Salvelinus malma) in Southeastern Alaska

1973 ◽  
Vol 30 (4) ◽  
pp. 543-548 ◽  
Author(s):  
R. F. Blackett
Keyword(s):  
Egg Size ◽  
Fish Length ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Ovary Weight ◽  
Dolly Varden Salvelinus Malma ◽  
Egg Number ◽  
Unit Of Length ◽  
The Right ◽  
Linear Regressions

Fecundity of resident Dolly Varden (Salvelinus malma) in an isolated population of southeastern Alaska averaged 66 eggs per female in comparison with 1888 eggs for anadromous Dolly Varden from two nearby streams. A relatively large egg size, averaging 3.6 mm in diameter and overlapping the range for the anadromous char, has been retained by the females in the resident population. Curvilinear regressions between egg number and fish length and linear regressions between egg number and body and ovary weights show that resident females have fewer eggs per unit of length, approximately the same number of eggs per gram of body weight, and more eggs per gram of ovary weight than anadromous females. The resident char attain sexual maturity a year earlier in life and at a smaller size than the migratory char. Development of a larger left ovary containing more eggs than the right was a common occurrence for both resident and anadromous Dolly Varden.

Isolated Fluvial Population of Dolly Varden Salvelinus malma on Bering Island (Commander Islands)

2021 ◽  
Vol 61 (3) ◽  
pp. 418-432
Author(s):  
A. M. Malyutina ◽  
K. V. Kuzishchin ◽  
A. V. Semenova ◽  
M. A. Gruzdeva
Keyword(s):  
Dolly Varden ◽  
Salvelinus Malma ◽  
Commander Islands ◽  
Dolly Varden Salvelinus Malma ◽  
Bering Island

Predation by River Otters (Lutra canadensis) on Juvenile Coho Salmon (Oncorhynchus kisutch) and Dolly Varden (Salvelinus malma) in Southeast Alaska

1993 ◽  
Vol 50 (2) ◽  
pp. 312-315 ◽  
Author(s):  
C. Andrew Dolloff
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
River System ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Southeast Alaska ◽  
River Otters ◽  
Juvenile Salmonids ◽  
Dolly Varden Salvelinus Malma ◽  
Lutra Canadensis

The effect of predation by river otters (Lutra canadensis) on juvenile coho salmon (Oncorhynchus kisutch) and Dolly Varden (Salvelinus malma) in a Southeast Alaska watershed was inferred by examining the number and size distribution of sagittal otoliths that were found in otter scats. Individual scats contained up to 408 otoliths, indicating that at least 200 fish had been eaten between defecations. Otoliths from juvenile salmonids outnumbered those from coastrange sculpins (Cottus aleuticus) by about six to one. Based on examination of over 8000 otoliths found in otter scats, at least 3300 juvenile salmonids were eaten by two river otters and their two young in the Kadashan River system during a 6-wk period in late spring 1985.

Trophic biology and migratory patterns of sympatric Dolly Varden (Salvelinus malma) and Arctic char (Salvelinus alpinus)

2016 ◽  
Vol 94 (8) ◽  
pp. 529-539 ◽  
Author(s):  
A.M. Dennert ◽  
S.L. May-McNally ◽  
M.H. Bond ◽  
T.P. Quinn ◽  
E.B. Taylor
Keyword(s):  
Sockeye Salmon ◽  
Trophic Ecology ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Migration Patterns ◽  
Dolly Varden Salvelinus Malma ◽  
Migratory Patterns ◽  
Similar Body

The trophic ecology (diet and head morphology) and migration patterns of two closely related salmonid fishes, Arctic char (Salvelinus alpinus (L., 1758)) and Dolly Varden (Salvelinus malma (Walbaum, 1792)), were examined in tributaries of Lake Aleknagik, southwestern Alaska, to test for differentiation between species. Schoener’s index of proportional overlap and multivariate analyses of diets suggested that these species had significantly different trophic niches. Arctic char and the largest individuals of both species had the most diverse diets, and sockeye salmon (Oncorhynchus nerka (Walbaum, 1792)) eggs dominated the diet of both species, especially Arctic char. Arctic char had larger jaws and wider heads than Dolly Varden of similar body length, which may contribute to interspecific diet difference. The species also differed in migration patterns; otolith microchemistry indicated that juvenile Arctic char were produced by nonanadromous mothers, whereas the mothers of the Dolly Varden had been to sea in the season prior to spawning. The species also segregate in spawning habitat (Arctic char in the lakes and Dolly Varden in streams), as well as in juvenile rearing habitat. Our study provides the first evidence of divergent feeding and migratory ecology between sympatric juvenile Arctic char and Dolly Varden, differences that may constrain hybridization and introgression between them.

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