We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Contrasting the early life histories of sympatric Arctic gadids Boreogadus saida and Arctogadus glacialis in the Canadian Beaufort Sea.
- Authors
Bouchard, Caroline; Mollard, Salomé; Suzuki, Keita; Robert, Dominique; Fortier, Louis
- Abstract
The early life stages of Boreogadus saida and Arctogadus glacialis are morphologically similar, making it difficult to assess differences in their ecological niche. The present study documented for the first time the early life stage ecology of A. glacialis, compared it to that of B. saida, and identified the factors separating the niches of the two sympatric species. The 10,565 larval gadids collected in the Beaufort Sea from April to August of 2004 and 2008 were identified to species either directly by genetics and/or otolith nucleus size, or indirectly with a redistribution procedure. Between 8.0 and 8.7 % of all gadids were assigned to A. glacialis. Larvae of A. glacialis were longer at hatch and experienced lower mortality rates than those of B. saida. The two species shared similar spatiotemporal and vertical distributions, hatching season, and growth rate. Under the ice, feeding incidence of B. saida was low (14 %) relative to A. glacialis (88 %). At lengths <15 mm, both species specialized on different prey. The diet of fish >15 mm overlapped (Schoener's index = 0.7), with Calanus glacialis and C. hyperboreus providing >50 % of the carbon intake of both species. The higher mortality in B. saida may be explained by the smaller size at age from hatching to metamorphosis and a lower under-ice feeding incidence. The early larval stage appears to be the key period of niche divergence between the two species.
- Subjects
BOREOGADUS saida; ARCTOGADUS glacialis; FISH mortality; FISH morphology; FISH larvae; FISH growth
- Publication
Polar Biology, 2016, Vol 39, Issue 6, p1005
- ISSN
0722-4060
- Publication type
Article
- DOI
10.1007/s00300-014-1617-4