Swimming Performance and Physiological Responses to Exhaustive Exercise in Radio-Tagged and Untagged Pacific Lampreys

Abstract

Populations of Pacific lamprey Lampetra tridentata have declined in the Columbia River basin. One factor that may have contributed to this reduction in population size is an excessive use of energy by adult lampreys as they negotiate fishways at dams during spawning migrations. To gain an understanding of the performance capacity of Pacific lampreys, we estimated the critical swimming speed (Ucrit) and documented physiological responses of radio‐tagged and untagged adult lampreys exercised to exhaustion. The mean (±SD) Ucrit of untagged lampreys was 86.2 ± 7.5 cm/s at 15°C, whereas the Ucrit for radio‐tagged lampreys was 81.5 ± 7.0 cm/s, a speed that was significantly lower than that of untagged fish. The physiological responses of tagged and untagged lampreys subjected to exhaustive exercise included decreases in blood pH of 0.3–0.5 units, a 40% decrease in muscle glycogen levels, a 22% increase in hematocrit for untagged fish only, and a 4‐ to 5‐fold increase in muscle and a 40‐ to 100‐fold increase in plasma lactate concentrations. These physiological changes were significant compared with resting control fish and usually returned to resting levels by 1–4 h after fatigue. Our estimates of Ucrit for Pacific lampreys are the first quantitative measures of their swimming performance and suggest that these fish may have difficulty negotiating fishways at dams on the Columbia River, which can have water velocities approaching 2 m/s. Our physiological results indicate that tagged and untagged Pacific lampreys show similar metabolic dysfunction after exhaustive exercise but recover quickly from a single exposure to such a stressor.

Swimming Behaviour of Juvenile Pacific Lamprey, Lampetra tridentata

“…In contrast to eel, juvenile Pacific lamprey swim downstream or with the river current when migrating to the Pacific Ocean. Critical swim speeds of juvenile lamprey were only 40% of those reported by Mesa et al (2003) for adult Pacific lamprey that migrate upstream to spawn.…”

Population ecology of the sea lamprey (Petromyzon marinus) as an invasive species in the Laurentian Great Lakes and an imperiled species in Europe

“…In areas of fast water velocity, a combination of intermittent burst swimming and periods of rest when attached to the substrate is characteristic behavior (Applegate 1950;Hardisty and Potter 1971b;Haro and Kynard 1997;Mesa et al 2003;Quintella et al 2004). This highly active swimming is the most energy-inefficient form of activity (Beamish 1978) and can only be achieved for short periods.…”

Laboratory protocol to calibrate sea lamprey (Petromyzon marinus L.) EMG signal output with swimming

“…During their anadromous migration, sea lampreys do not feed and therefore have a finite amount of energy reserves not only to complete migration, but also for sexual maturation and spawning (Beamish, 1980). The physiological and behavioural processes involved in spawning success can be compromised by human and/or natural obstacles responsible for the waste of excessive amounts of energy (Mesa et al, 2003;Quintella et al, 2004).…”

“…The anguilliform type of locomotion used by lampreys is recognized to be less efficient than the sub-carangiform motion used by salmonids (Beamish, 1974(Beamish, , 1978Mesa et al, 2003;Quintella et al, 2004). The poor swimming capacity of sea lampreys already observed in the laboratory (Beamish, 1974;Hanson, 1980;Bergstedt et al, 1981) is again explored in this approach by the application of the standard measurement critical swimming speed, similar to the one applied by Mesa et al (2003) to the Pacific lamprey Lampetra tridentata (Richardson, 1836).…”