SwePub
Sök i LIBRIS databas

  Extended search

L773:0016 6480
 

Search: L773:0016 6480 > Photoperiod regulat...

  • Björnsson, Björn Thrandur,1952Gothenburg University,Göteborgs universitet,Zoologiska institutionen,Department of Zoology (author)

Photoperiod regulation of plasma growth hormone levels during induced smoltification of underyearling Atlantic salmon.

  • Article/chapterEnglish2000

Publisher, publication year, extent ...

  • Elsevier BV,2000

Numbers

  • LIBRIS-ID:oai:gup.ub.gu.se/74395
  • https://gup.ub.gu.se/publication/74395URI
  • https://doi.org/10.1006/gcen.2000.7439DOI

Supplementary language notes

  • Language:English

Part of subdatabase

Classification

  • Subject category:ref swepub-contenttype
  • Subject category:art swepub-publicationtype

Notes

  • Earlier studies have established that increased daylength increases plasma growth hormone (GH) levels during spring smoltification of yearling Atlantic salmon. Recently, the Atlantic salmon aquaculture industry has started the production of underyearling ("summer") smolts. This involves fast juvenile growth on continuous light (24L), the transfer of juveniles over 8 cm in length to short day (12L) for 6 weeks in the summer, followed by transfer to 24L for another 6 weeks before transfer to seawater in late October. Three groups were studied in fresh water from July to the following May in order to elucidate the GH response to this photoperiod manipulation: one group was kept on 24L throughout (long-day group), while the other two groups were exposed to short day from July 15th. Of these, one was brought back onto long day on September 1st (winter group) while the other was kept on short day (short-day group). Plasma GH levels of the long-day group were around 1.6 ng/ml throughout the study. The short-day transfer suppressed GH levels to 0.7 ng/ml within 2 weeks (short-day and winter groups). The long-day transfer (winter group) increased GH levels to 11 ng/ml within 3 weeks, and this elevation of GH levels was sustained for about 3 months, before declining to pretreatment levels. The study demonstrates that underyearling Atlantic salmon react to increased daylength in a way similar to traditional yearling smolts. It also demonstrates for the first time that decreased daylength can suppress plasma GH levels in fish. It is concluded that winter photoperiod manipulation causes an out-of-season initiation and completion of the parr-smolt transformation of underyearling Atlantic salmon and that growth hormone plays a major role in this process.

Subject headings and genre

Added entries (persons, corporate bodies, meetings, titles ...)

  • Hemre, G I (author)
  • Bjørnevik, M (author)
  • Hansen, T (author)
  • Göteborgs universitetZoologiska institutionen (creator_code:org_t)

Related titles

  • In:General and comparative endocrinology: Elsevier BV119:1, s. 17-250016-6480

Internet link

Find in a library

To the university's database

Find more in SwePub

By the author/editor
Björnsson, Björn ...
Hemre, G I
Bjørnevik, M
Hansen, T
About the subject
NATURAL SCIENCES
NATURAL SCIENCES
and Biological Scien ...
and Zoology
Articles in the publication
General and comp ...
By the university
University of Gothenburg

Search outside SwePub

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Close

Copy and save the link in order to return to this view