Pallid sturgeon can be long-lived, with females reaching sexual maturity later than males (Keenlyne and Jenkins 1993).
Based on wild fish, estimated age at first reproduction was 15 to 20 years for females and approximately 5 years for males (Keenlyne and Jenkins 1993). However, like most fish species, water temperatures can influence growth and maturity. Female hatchery-reared pallid sturgeon maintained in an artificially controlled environment (i.e., near constant 16 to 20oC temperatures) reached sexual maturity at age 6, whereas female pallid sturgeon subject to colder winter water temperatures reached maturity around age 9 (Webb in litt., 2011). Thus, age at first reproduction could vary based on local conditions.
Females do not spawn each year (Kallemeyn 1983). Observations of wild pallid sturgeon collected as part of the conservation stocking program in the northern part of the range indicates that female spawning periodicity is 2-3 years (Rob Holm, USFWS Garrison Dam Hatchery, unpublished data).
Fecundity is related to body size. The largest upper Missouri River fish can produce as many as 150,000-170,000 eggs, whereas smaller bodied fish may only produce 15,000-30,000 eggs.
Spawning appears to occur between March and July, with lower latitude fish spawning earlier than those in the northern portion of the range. Adult pallid sturgeon can move long distances upstream prior to spawning, and females likely are spawning at or near the apex of these movements (Bramblett and White 2001; DeLonay et al. 2009). This behavior can be associated with spawning migrations (U.S. Geological Survey (USGS) 2007; DeLonay et al. 2009). Spawning appears to occur over firm substrates, in deeper water, with relatively fast, turbulent flows, and is driven by several environmental stimuli including flow, water temperature, and day length (USGS 2007; DeLonay et al. 2009).
Incubation rates are governed by and dependent upon water temperature. In a hatchery environment, fertilized eggs hatch in approximately 5-7 days (Keenlyne 1995). Incubation rates may deviate slightly from this in the wild. Newly hatched larvae are predominantly pelagic, drifting in the currents and dispersing downstream from the hatching site for 11 to 13 days (Kynard et al. 2002, 2007; Braaten et al. 2008, 2010).