Electromyogram Telemetry, Nondestructive Physiological Biopsy, and Genetic Markers: Linking Recent Techniques with Behavioral Observations for the Study of Reproductive Success in Sockeye Salmon Mating Systems

摘要

There has been little investigation into the physiological and energetic factors affecting reproductive success in free-swimming, spawning fish. One of the major impediments has been the lack of methods for nonlethally studying individual-specific energetics and physiological condition, as well as the lack of utilization of technologies for associating specific behaviors with energetics, condition, and fertilization success. Here we review three approaches (electromyogram [EMG] telemetry, nondestructive physiological sampling, and microsatellite analysis) that have recently been used to examine individual specific differences in behavior, energetics, and physiology in spawning sockeye salmon Oncorhynchus nerka. We also review major findings from other studies that have used these approaches in the context of how they were, or could have been, used to assess reproductive success in sockeye. Electromyogram telemetry can provide both estimates of individual specific energy expenditures during spawningand help identify energetic costs of specific reproductive behaviors. Nondestructive physiological sampling can provide information into pre- and postspawning levels of energy, hormones, and metabolites, enabling assessments of physiological stress, reproductive preparedness, and osmoregulatory function. Microsatellite analysis is a genetic marker technique that enables an assessment of parentage. We discuss several of the strengths of these research approaches and the value of integrating them with studies of fish behavior as a means of significantly advancing our understanding of individual variation in reproductive success of spawning salmonids.