Life history and growth of Asellus aquaticus (L.) in relation to environment in a eutrophic lake in Norway

  • Økland K
  • 12

    Readers

    Mendeley users who have this article in their library.
  • 28

    Citations

    Citations of this article.

Abstract

A new life history pattern for Asellus aquaticus is described from Lake Østensjøvatn in Oslo. Overwintering specimens (generation A) breed in spring. The next generation B matures, breeds and dies in first summer, giving rise to the overwintering generation C, which breeds next spring and dies. The death of generation B in its first summer could be shown by a study of oostegit development in the females. The end of the breeding season in autumn is thus accomplished by a complete replacement of generations. This pattern can be a) light stimulated, or b) a pre-determined cycle, uninfluenced by environmental factors. Breeding starts in spring when water temperature reaches about 7–8°C. Estimated incubation time was 23–35 days, corresponding to about 300 degree-days above 4°C. No growth took place from November till March–April. Growth started when water temperature reached 3–5°C. Growth increments per degree-day above 3°C were the same for the three generations which were followed, in spite of their different life spans and different temperatures. The total number of degree-days above 3°C available to the generations seemed to regulate the maximum length of the specimens in the respective generations. Comparison with life histories of the species in other lakes suggests that the different patterns described reflect an evolutionary adaptation to major environmental factors.

Author-supplied keywords

  • Asellus aquaticus
  • degree-days
  • evolutionary adaptation
  • growth
  • life history
  • temperature

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • Karen Anna Økland

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free