GRAYLING OF GREBE LAKE, YELLOWSTONE NATIONAL PARK, WYO. 



By Thomas E. Kruse, Fishery Research Biologist, BUREAU OF sport fisheries and wildlife 



The holarctic grayling, Thymallus arcticus 

 Pallas, is one of the rarest North American game 

 fishes. Its localized distribution on this continent , 

 as well as the great beauty of the fish, have focused 

 the interest and concern of ichthyographers and 

 sportsmen on the species. 



The first specimens to be collected in America 

 were from Winter Lake near Fort Enterprise 

 (Northwest Territories) and were identified by 

 Sir John Richardson who called them Back's gray- 

 ling (Franklin 1823). The grayling was subse- 

 quently found in Michigan and Montana and in 

 many streams of Alaska and Canada eastward to 

 the western shore of Hudson Bay. This distribu- 

 tional pattern was evidently the result, first, of 

 glacial action which extended the range south- 

 ward, and second, of later habitat changes which 

 left only two relict populations south of the 

 Canadian border. 



The grayling of North America is conspecific 

 with the Asiatic form, Thymallus arcticus Pallas 

 (Walters 1955; Wilimovsky 1954). Walters (1955) 

 further recognizes for North American individuals 

 the subspecies signifer (for Alaska and Canada 

 specimens) and tricolor (for Michigan-Montana 

 individuals). 



In Eurasia, Thymallus arcticus occurs from the 

 Ob system of western U.S.S.R. to the eastern 

 Siberian Coast (including all streams draining into 

 the Bering Sea and the Penzhina River draining 

 into the Sea of Okhotsk), and south to the Baikal 

 basin, Sea of Japan basin, and the Yellow Sea 

 basin (Yalu River) (Walters 1955). 



In Canada and Alaska the grayling is found in 

 the Arctic Ocean drainages, and from the Bering 

 Sea drainages and the Alsek River and Stikine 

 system of Pacific Coast drainages, east to the 

 western shore of Hudson Bay. The southern limit 

 is the headwaters of the drainages concerned and 

 south along the west shore of Hudson Bay to just 

 north of the Nelson svstem in Manitoba (Walters 

 1955). 



Note— Approved for publication July 8, 1958. Fishery Bulletin 149. 



In the United States, the grayling was indig- 

 enous to the following two areas: (1) the upper 

 part of Michigan's Lower Peninsula, and in the 

 Otter River of the Upper Peninsula (Hubbs and 

 Lagler 1949), and (2) headwaters of the Missouri 

 River above the Great Falls in Montana (Henshall 

 1902). 



In Michigan, the grayling is a fish population 

 of the past. Its disappearance has been attributed 

 to many factors. Those most often cited are 

 logging drives during the spawning season, compe- 

 tition with other species, deforestation and con- 

 sequent rise in water temperatures, and fishing 

 pressure. Streams such as the Manistee River, 

 where the grayling was once so abundant that 

 two men and two women were reported to have 

 caught 3,000 individuals in 14 days and to have 

 hauled 2,000 of them to Chicago, are now barren 

 of the species (Creaser and Creaser 1935). 



Transplantations from Montana have met with 

 little success in distant States. Somewhat better 

 results have been attained by stocking within the 

 State itself. Grayling introduced into Georgetown 

 Lake and Rogers Lake, Mont., for example, 

 supplied for many years the majority of spawn 

 taken for fish cultural purposes by the Montana 

 Game and Fish Commission (Moffett 1950). How- 

 ever, even within Montana the range of the gray- 

 ling has decreased. It is rarely observed in the 

 Madison River drainage and is absent entirely 

 from the Missouri River, the Gallatin River, and 

 the main stem of the Jefferson River. The only 

 indigenous population maintaining itself at 

 present is in the Red Rock Lakes region of the 

 Beaverhead drainage, where its management was 

 studied by Nelson (1954). 



Foremost among the individuals who have 

 studied the grayling is Dr. C. J. D. Brown (1938a, 

 1938b, 1939, 1943) who did research on age and 

 growth, food habits, habitat, and spawning be- 

 havior. Watling and Brown (1955) investigated 

 the early embryology of the grayling. Moffett 

 (1950) reported briefly on the status of the grayling 

 in Grebe Lake. 



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