Secondary sexual characters and sperm traits in coho salmon Oncorhynchus kisutch
Abstract:A study was undertaken to examine secondary sexual characters (spawning colouration and overall body size) in relation to sperm metrics in one alternative reproductive tactic of coho salmon Oncorhynchus kisutch: large hooknose males that spawn in dominance-based hierarchies. Males with less intense red spawning colouration had higher sperm velocities than males with darker red spawning colouration. There was no relationship between male body size and sperm metrics. These results suggest that within an alternative reproductive tactic, variation in sperm competition intensity may select for a trade-off between investment in sexual colouration and sperm quality.
Document Type: Regular Paper
Affiliations: Department of Biological Sciences, University of Windsor, Windsor, Ontario N9B 3P4 Canada
Publication date: May 1, 2009