Environmental Biology of Fishes

, Volume 47, Issue 1, pp 43–50

The migration of spawning stocks of graylingThymallus thymallus, in Lake Mjøsa, Norway

  • Harald Kristiansen
  • Kjell B. Dølving
Article

DOI: 10.1007/BF00002378

Cite this article as:
Kristiansen, H. & Dølving, K.B. Environ Biol Fish (1996) 47: 43. doi:10.1007/BF00002378

Synopsis

The migration of grayling was studied in Lake Mjøsa and 13 of its tributaries in which grayling spawn. The study demonstrate that grayling spawn in creeks in May/June and leave for Lake Mjøsa shortly after spawning to return the next spring. Once mature, the grayling spawn every year. Grayling mix in the lake and are found at a mean distance of 11.9 km from the estuary of their spawning creek in September. Grayling embryos hatch in June and the juveniles stay in the tributaries until September/October. Grayling spend the winter months in the lake. Out of 1599 grayling tagged in tributaries during the spawning season, 240 of 284 recaptures (84.5%) were made in subsequent spawning seasons in the same tributary in which they were first tagged. Forty-four grayling were recaptured in adjacent tributaries. These results demonstrate that, despite the fact that all grayling leave the tributaries and mix in the lake, there is a high precision of homing. It is suggested that the grayling population in lake Mjøsa is composed of stocks using specific tributaries for spawning.

Key words

Life historyGrowthMaturityPopulation specificity

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Harald Kristiansen
    • 2
  • Kjell B. Dølving
    • 1
  1. 1.Department of BiologyUniversity of OsloOslo 3Norway
  2. 2.Tranberg videregáende skoleGjøvikNorway