The Montana Grayling

Abstract

Montana grayling are now found, with few exceptions, only in the headwaters of the Big Hole River, Montana, and in lakes of that region. Despite their restricted distribution, the grayling make spirited spawning runs from these waters into various small inlets. Cultural operations have been successful in maintaining good populations in waters still frequented by grayling. Though apparently suitable spawning grounds are present in the West Gallatin, stocking must be continued to maintain satisfactory fishery under the present fishing pressure.

Status report on fluvial arctic grayling (Thymallus arcticus) in Montana

“…Brown (1943) reported that the distribution of fluvial grayling had been reduced to the Big Hole River drainage and the upper Gallatin River, with their presence in the latter due to plantings of fingerlings. Tyron (1947) confirmed the plantings of grayling fingerlings into the Gallatin River and also stated that "with few exceptions" (unspecified), grayling were only found in the upper Big Hole River and in lakes.…”

“…After reviewing efforts in Alaska, Armstrong (1986) also concluded that stocking of grayling fry into streams has not proven successful. However, this cannot explain all failures since some later plantings were with larger juveniles up to 15 cm (Tyron 1947). The…”

“…Spawning in extremely shallow water has also been observed of grayling from Rogers Lake (Tyron 1947) and Deer Lake. Many in the Deer Lake outlet spawn in water only about 8 cm (3 inches) in depth (author, pers.…”

“…Montana has been reported to occur at temperatures of about 4.4 to 10°C (Brown 1938;Tyron 1947;Peterman 1972;Lund 1974;Wells 1976). The author observed intense spawning activity at 15.2°C in the Deer Lake outlet on July 10, 1990, a year when spawning was delayed by cool late spring-early summer weather and late ice-out on Deer Lake.…”

“…Time required for embryonic development to hatching and to swimup varies with water temperature. Kratt and Smith (1977) (Tyron 1947); two weeks to hatching at 10°C and swimup in an additional week to 10 days (Henshall 1907); 16 days to hatching at 10-14.4°C (Watling and Brown 1955); 13.7 days average time to hatching at 8.8°C (Bishop 1971); and 14 to 19 days to hatching at 8°C and approximately 10 additional days to swimup (Wojcik 1955;Kaya 1989).…”