Divergent life histories among smallmouth bass Micropterus dolomieu inhabiting a connected river–lake system

Abstract

Annual reproductive surveys monitored nesting location, reproductive success and the age and size of individually tagged male smallmouth bass Micropterus dolomieu that reproduced in Millers Lake, a 45 ha widening of the Mississippi River, Ontario, and in a 1Á5 km pool and riffle section of the river directly upstream. The vast majority of males displayed fidelity to either the river or the lake as reproductive habitat throughout their lifetimes. Nearly, half of the males that reproduced in successive years exhibited strong nest-site fidelity by nesting within 20 m of their previous year's nest site. In most years, when compared to those in the lake, reproductive males in the river differed significantly in reproductive characteristics including age and size at maturation and nesting success rates. A 3 year telemetry project identified two distinct habitat use patterns: lake-resident fish remained in the lake throughout the year and potamodromous individuals migrated from the lake to upriver spawning habitat in the spring and then returned to the lake prior to the onset of winter. Integration of habitat use and reproductive data suggests that there are significant differences in the life-history strategies of fish that reproduce in the river v. the lake.

The ghost of introduction past: Spatial and temporal variability in the genetic diversity of invasive smallmouth bass

“…In total, 53 formalin‐fixed specimens representing 11 drainage systems were obtained for genetic analyses (Table 1). These specimens represent a subset of the M. dolomieu genetic diversity that was present in the native range 20–25 generations ago (Barthel et al., 2008). …”

Oxidative ecology of paternal care in wild smallmouth bass, Micropterus dolomieu

“…The study site is bordered upstream by a 12 m waterfall and downstream by an extensive series of rapids and waterfalls, both of which serve as barriers to at least upstream movement. Radio telemetry studies have not detected fish movement out of the study site in either direction (Barthel et al, 2008). The study site is relatively isolated and receives negligible fishing pressure.…”

“…This population has been the subject of a long-term (>20 years) study on the reproductive ecology of smallmouth bass, and the reproductive history of all adult males reproducing in the system is known for the study period (Barthel et al, 2008). For a full description of the study site, see Barthel et al (2008).…”

“…This population has been the subject of a long-term (>20 years) study on the reproductive ecology of smallmouth bass, and the reproductive history of all adult males reproducing in the system is known for the study period (Barthel et al, 2008). For a full description of the study site, see Barthel et al (2008). Briefly, the study site is composed of distinct upstream riverine (Mississippi River) and downstream lacustrine (Miller's Lake) habitats, separated by a 1 m waterfall that is not a complete barrier to smallmouth bass movement.…”

“…The self-assessment of an individual male's future reproductive opportunities, however, is more complex and likely to be related to the age, size and physiological status of the parental male, which in turn is affected by the individual's age at maturation and previous reproductive history. Smallmouth bass can mature at various ages both within and among populations, from as young as 2-3 years to as old as 6-7 years (Barthel et al, 2008), which can result in an array of different growth trajectories and longevity expectations. In general, if age at maturation is similar among males within a population, then younger (and smaller) males usually have less valuable current broods (i.e.…”