Weight‐Dependent Intraspecific Variation in Reproductive Parameters of Female Golden Topminnows.

A culture demand has developed within the ornamental and baitfish industries for fishes of the genus Fundulus. Refining reproductive methods may not only benefit important industries, but related species of conservation concern as well. Golden Topminnows Fundulus chrysotus are a common fish species across their native range and they have their own ornamental demand. Low fecundity observed in species of Fundulus has been the main obstacle to their efficient culture. Therefore, the objective of this study was to determine the optimal female broodfish size for increasing certain reproductive parameters (fecundity, embryo, and larval morphometrics), which ultimately contributes to better survival from embryo to larva. Outdoor and indoor studies were conducted between April 2018 and July 2018. Three distinct female size‐classes were stocked in an indoor recirculating aquaculture system and outdoor mesocosms. The indoor study involved palpating females once every 3–4 d for 2.5 weeks, and the outdoor study utilized mesocosms to assess natural embryo and larval metrics over a 10‐week period. In indoor laboratory experiments, large females ovulated the greatest numbers of eggs; however, the number of eggs per gram (female weight; mean ± standard error of the mean) was proportional across all three size‐classes (small: 2.8 ± 0.64; medium: 2.3 ± 0.51; large: 3.1 ± 0.51). In outdoor mesocosm experiments, larval TL and percentage of embryos surviving to hatch were lowest for large size‐class progeny, which may have resulted from their relatively larger chorion size and nonstandardized incubation density contributing to inhibited development. Female Golden Topminnows proportionally invest in yolk production, and thus produce greater numbers of eggs. [ABSTRACT FROM AUTHOR]