From http://www.bio.txstate.edu/~tbonner/txfishes/index.htm

Fecundity: A single females may produce 6803-10164 eggs (mean 8604), over the entire spawning season, and may have participated in 16-26 spawning sequences. A female might produce from 9-1136 eggs (mean 414) in a day (Gale and Buynak 1982). Hatching occurs in approximately 13 days at 15 degrees C, decreasing to 4 days at 25 degrees C (Markus 1934; Andrews and Flickinger 1974).



Age at maturation: Markus (1934) and Dobie et al. (1956) found that young hatched in late May in Iowa and Missouri had reached sexual maturity and reproduced by late July of the same year.



Migration: During periods of high stream discharge, fathead minnows showed downstream movement in small Minnesota stream (Schlosser 1995).



Growth and population structure: In Ohio, young of year in October were 13 mm (Aug.-Sept. hatchings) - 64 mm (May-June hatchings) in length (TL); around 1 year length ranged from 25-76 mm; adults usually 41-76 mm in length (Trautman 1981).