Lackmann, an assistant professor in the Department of Mathematics and Statistics at the University of Minnesota Duluth, uses advanced aging techniques to document the age of the bigmouth buffalo fish in Minnesota, which is over 100 years old. He examines the fish scales and extracts the otolith or ear stone from inside the fish's skull, and then thinly slices the stone to determine its age.

The evidence outlined in this new study suggests that over 90% of the population of buffalo fish found in the Salt River reservoir, located 160 miles north of Tucson, is at least 80 years old.

This finding indicates that most of them may have hatched in the 1920s or earlier, including individuals introduced to Arizona in 1918 and estimated to be "still alive in 2023," as stated in the study. This research was published last month in the journal Scientific Reports.