The Reproductive Behaviour And Ecology Of Smallmouth Bass (micropterus Dolomieui) In Long Point Bay, Lake Erie

The reproductive behaviour and ecology of smallmouth bass, Micropterus dolomieui, was studied during the 1981 to 1983 spawning seasons at Long Point Bay, Lake Erie. SCUBA was used to find a observe nesting males. My observations of these fish revealed some behaviours that were not previously described. Other activities, e.g. parental guarding, were segregated into discrete behaviour patterns. These units were organized into an ethogram of reproductive behaviour. A mating system involving selectivity by males in choosing mates was discussed.;Reproductive success of individual male smallmouth was measured by collecting new black-fry from nests. Thirteen variables reflecting differences in biological characteristics of the male, time in the season and particular habitat features in or near the nest were measured. The significant influences on reproductive success were evaluated through a sequence of statistical analyses. Principal components analysis on the 13 predictor variables provided a subset of 5 independent component variables containing 95% of the original variation. A multivariate analysis of variance on the PC scores of the variables indicated differences between years. Discriminant function analysis using data from different years as groups, identified that the physical environmental component (primarily the accumulated hours of wind greater than Beaufort force 4 during offspring development) was responsible for these differences. Multiple regressions of the component variables with reproductive success demonstrated that windy hours and the material in the bottom of the nests significantly influenced the numbers of black-fry in nests.;Renesting by male smallmouth that prematurely lost their brood was studied in 54 marked fish. Nest mortality was simulated by removing black-fry . Twelve males (22%) undertook a second reproductive effort in their same territory. Renesting males were older and larger than those males that nested only once in a territory. Numbers of black-fry on both efforts did not differ significantly. All renesting males reared offspring to the black-fry stage a second time. Renesting effectively mitigated the failure of a first reproductive effort in one season