To fast or feed: an alternative life history for anadromous brook trout Salvelinus fontinalis overwintering within a harbour |
| |
| Authors: | A D Spares M J Dadswell J MacMillan R Madden R K O'Dor M J W Stokesbury |
| |
| Institution: | 1. Ocean Tracking Network, Dalhousie University, Biology Department, , Halifax, NS, B3H 4J1 Canada;2. Department of Biology, Acadia University, , Wolfville, NS, B4P 2R6 Canada;3. Nova Scotia Department of Fisheries and Aquaculture, Inland Fisheries Division, Resource Management Section, , P. O. Box 700 Pictou, NS, B0K 1H0 Canada |
| |
| Abstract: | The seasonal feeding pattern of sea‐run brook trout Salvelinus fontinalis was studied from November to May 2010–2012 in Antigonish Harbour, Nova Scotia, Canada (45° 38′ N; 61° 55′ W). Sixty‐three S. fontinalis (mean ± s.d . fork length = 330 ± 70 mm and mass = 536 ± 351 g) captured had fed predominantly on fishes (Fundulidae and Gasterosteidae). Percentage of empty stomachs was highest during autumn (18%) and winter (22%) and lowest in spring (7%). Stomach fullness increased from autumn to a maximum during winter, relating to near‐zero body temperatures which may have effectively stopped gastric evacuation. Although feeding occurred during winter (December to March), consumption rates were calculated as negative values, and subsequently returned to positive values in spring (April to May). The over‐winter life‐history strategy of this sea‐run S. fontinalis population appears to be a feeding marine migration in which fish continually increase body condition, representing an alternative to the more common overwintering strategy of starvation in fresh water until spring. |
| |
| Keywords: | body condition body temperature consumption rates marine migration seasonal diet stomach fullness |
|
|
