In:
Canadian Journal of Zoology, Canadian Science Publishing, Vol. 76, No. 12 ( 1998-12-01), p. 2186-2193
Abstract:
Rheotactic response was quantified for newly emerged sockeye salmon (Oncorhynchus nerka) fry from a beach population (Pleasure Point) and from an adjacent inlet population (Cedar River). The Pleasure Point population was small in number and had been established by straying from the much larger Cedar River population no more than 13 generations previously. When tested in laboratory raceways, fry from the Cedar River population were displaced downstream in the dark but not in the light. Such behavior is typical of inlet populations and presumably reflects selection for rapid movement to rearing lakes with minimal losses to predation. Fry from the Pleasure Point population showed greater downstream displacement than the Cedar River fry. Behavioral divergence of the Pleasure Point population could not be explained by selection, because water movement was absent from the beach environment. Genetic drift appeared to be a more plausible divergence mechanism. We suggest that the rheotactic response of beach populations should reflect the founding genotypes, gene flow from other populations, and random genetic drift. The results of previously published studies on the rheotactic response of beach fry in two other lake systems qualitatively support our hypothesis.
Type of Medium:
Online Resource
ISSN:
0008-4301
,
1480-3283
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
1998
detail.hit.zdb_id:
1490831-1
SSG:
12
