If you are experiencing problems downloading PDF or HTML fulltext, our helpdesk recommend clearing your browser cache and trying again. If you need help in clearing your cache, please click here . Still need help? Email help@ingentaconnect.com

Effects of dietary soybean meal and photoperiod cycle on osmoregulation following seawater exposure in Atlantic salmon smolts

$48.00 plus tax (Refund Policy)

Download / Buy Article:

Abstract:

Atlantic salmon Salmo salar juveniles were fed either fishmeal-based diets (FM) or diets in which soybean meal (SBM) partly replaced the FM from first feeding on. The fish were kept at continuous daylight during the juvenile stage. During the last 3 weeks before reaching 100 g body mass, all fish were subjected to 12L:12D. Starting at 100 g body mass, groups of 60 fish from each feeding background were subjected to continuous light for 12 weeks (short winter), or a square-wave photoperiod cycle to stimulate parr to smolt transformation with 8L:16D during the first 6 weeks, and then continuous light during the last 6 weeks (long winter). After the 12 weeks, 20 fish from each treatment were subjected to 0, 24 or 96 h seawater exposure at a water salinity of 34. Hypo-osmoregulatory ability at seawater exposure was assessed by mortality, intestinal pathology, plasma ion concentrations and osmolality, gill Na+/K+-ATPase activity and element concentrations in the cytoplasm of distal intestinal enterocytes using X-ray microanalysis. The hypo-osmoregulatory capacity was higher in fish kept at short winter than at long winter, apparently due to more rapid development of gill Na+/K+-ATPase activity. Fish fed SBM suffered typical soybean meal-induced histological alterations of the distal intestine and apparent reductions in digestive function in the more proximal gastrointestinal regions. The net osmoregulatory capacity of these fish was maintained, as indicated by higher gill Na+/K+-ATPase activity and lower plasma Na+, Ca2+ and osmolality compared to the FM-fed fish. Thus, feeding SBM did not impair the hypo-osmoregulatory ability of the Atlantic salmon following seawater exposure.

Keywords: Na+/K+-ATPase; X-ray microanalysis; digestive enzymes; histology; ion concentration; osmolality

Document Type: Regular Paper

DOI: http://dx.doi.org/10.1111/j.1095-8649.2006.01201.x

Affiliations: 1: Department of Biology, University of Bergen, P. O. Box 7800, 5020 Bergen, Norway 2: Department of Medical Cell Biology, University of Uppsala, P. O. Box 571, 75123 Uppsala, Sweden 3: NIFES (National Institute of Seafood and Nutritional Research), P. O. Box 2029 Nordnes, 5817 Bergen, Norway

Publication date: November 1, 2006

Related content

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more