Inherited Differences in Agonistic Behavior between Two Populations of Coho Salmon

Publisher Website
Google Scholar
Abstract
Agonistic behaviors of juvenile coho salmon Oncorhynchus kisutch were compared between populations in Nathan Creek and Hope Slough, two tributaries of the lower Fraser River, British Columbia. Wild fish were tested individually in isolated aquaria for differences in the duration of lateral display. Hope Slough juveniles displayed more than did Nathan Creek juveniles. In two consecutive years, the differences between laboratory‐reared juveniles from these two populations were similar. In stream tanks, where the total repertoire of agonistic behavior by laboratory‐reared juveniles was compared, Hope Slough fish were more aggressive than Nathan Creek fish. When size‐matched pairs (one fish from each population) were placed in isolated aquaria, the Hope Slough juveniles became dominant. These data suggest a genetic basis for the observed behavioral differences in the laboratory‐reared fish, and further suggest that these differences also are characteristic of the two wild populations. The existence of these inherited interpopulation differences in agonistic behavior imply that the behaviors are adaptive. Growth conditions and densities of predators and competitors differ between the two streams and these factors may have acted selectively on the agonistic behavior of young coho salmon.

This publication has 15 references indexed in Scilit: