Great Plains Natural Science Society


The Prairie Naturalist

Date of this Version


Document Type



The Prairie Naturalist • 51(1): June 2019, pp 25-29


Copyright © 2019 The Great Plains Natural Science Society


Reproductive traits including fecundity, egg diameter, and condition of freshwater fishes influence offspring survival and abundance and may provide insight regarding timing of reproduction (Winemiller and Rose 1992, Johnston and Leggett 2002). Fish size (i.e., length or weight) may influence the number of eggs produced by an individual female (i.e., fecundity; Michaletz 1998). Larger individuals may, thus, disproportionately contribute to year-classes through increased fecundity if egg and larval survival is similar or greater than those from smaller reproductive females (Gwinn et al. 2015). Likewise, maternal fish size may influence egg diameter and offspring survival, whereby larger egg diameters are associated with greater parental care and increased egg quality (Sargent et al. 1987). Variation in egg diameter within and between individuals in a population may also indicate phenotypic plasticity in reproductive timing. For instance, intra-individual variation in egg diameter may indicate protracted spawning behavior (Pope et al. 1996). Inter-individual variation in egg diameter may indicate differences in sexual maturity and provide insight regarding timing of spawning (Hamel et al. 2015). Understanding relationships between fish size and reproductive traits is important for managing exploited fish populations where relaxed fishing regulations stemming from inaccurate reproductive information may lead to unintended consequences, including over-fishing and reduced population sustainability (Gwinn et al. 2015, Barneche et al. 2018).