Big Muddy Speaker Series presents:
Pallid sturgeon--graceful ghosts of the rivers of sand


In the more than 25 years since its listing as an endangered species, the pallid sturgeon has received ever increasing attention as efforts to conserve and restore the species have been implemented. Scientists have made significant progress in understanding the life history, behavior and biology of the species. Despite recent progress the species is still not well understood by many and the wide array of elegant adaptions the species has evolved to thrive in the Missouri and Mississippi Rivers are for the most part, under-appreciated.

Pallid sturgeon free embryo at approximately 2 days after hatch, approximately 11-12 mm (about 0.45 of an inch) in length.
Photograph by Kimberly Chojnacki, U.S. Geological Survey)

Pallid sturgeon embryos approximately 8 hours after fertilization. In the wild, the eggs would remain on the river substrate for 5-8 days before hatching. The young then drift downstream with the river current before finding a safe haven habitat.
(Credit: Kimberly Chojnacki, USGS. Public domain.)
We'll be joined by Aaron DeLonay, one of the country's foremost pallid sturgeon experts, who will introduce us to one of North America’s largest and rarest riverine predators from its first formative moments through its transformation to deadly riverine predator. Examine the Missouri River from the pallid sturgeon’s perspective and learn what it takes to survive in the swift current of the Missouri River. More than 90 million years in the making, this uniquely adapted, charismatic species is imperiled by the very adaptations that have made it successful for so long. We will examine the pallid sturgeon with a new appreciation informed by recent scientific studies and explore some of the emerging hypotheses that may provide answers to why the species is so rare, and where scientists are searching for the keys to species recovery.
Meet Your Presenter

Aaron DeLonay
, Ecologist with River Studies Branch of U.S. Geological Survey
Aaron DeLonay, one of the country's foremost pallid sturgeon experts.
Related Presentations
Resources & Links
Dig deeper for more info on this topic.
- The amazing Comprehensive Sturgeon Research Project blog, with behind the scenes stories about USGS River Studies research.
- Pallid Sturgeon Recovery Program Portal
- USGS River Studies Branch - Columbia Environmental Research Center
- USGS Science documents on Missouri River research
- Aaron DeLonay staff page, with links to research
The Big Muddy Speaker Series in Rocheport
is hosted by these wonderful partners.
Click here for a list of upcoming presentations»
Special thanks to Les Bourgeois Vineyards for giving us the opportunity to use their beautiful space overlooking the Missouri River. All speakers are presenting for free! Thank you all for sharing your knowledge with us!
The Big Muddy Speaker Series also takes place monthly in Kansas City and St. Charles.
The Big Muddy Speaker Series is partially funded by the Mo. Dept. of Conservation.
Upcoming Presentations

Missouri River Relief: 25 Years on the Big Muddy
November 10, 2026Columbia, MO
Join us for a journey through time celebrating 25 years of Missouri River Relief's work on the Big Muddy.
See Event
Plastic Pollution, Gulf Hypoxia, and Water Quality
November 11, 2026St Charles, MO
Jennifer Wendt from MidAmerica Clean Future guides us through understanding regional water quality challenges.
See Event