Varieties of Buffalofish as Negligibly Senescent Species
A number of vertebrate species exhibit negligible senescence, meaning little to no functional degeneration over the course of their lives. Usually they also exhibit very long life spans for their size, and in comparison to near relative species that do exhibit evident aging. Researchers study these species in order to (a) identify important mechanisms of degenerative aging as targets for further research, as well as to (b) potentially find adjustments to cellular biochemistry that might stop a given mechanism from contributing to aging in our species. The first goal is much more feasible in the near term; it remains to be seen as to whether the second is even plausible to engineer in our lifetimes. A necessary first step in this field of research is to identify which vertebrate species are in fact negligibly senescent. Less is known about life spans and life histories in the wild than one might think, and so one should expect the research community to continue to identify new examples as time goes on.
During the 1910s three buffalofish species (Catostomidae: Ictiobus cyprinellus, I. bubalus, I. niger) were reared in ponds along the Mississippi River. Individuals of these buffalofishes were transported to locations across the United States to support or establish commercial fisheries, including Roosevelt Lake, Arizona in 1918. During the 1930s-1960s a commercial fishery existed on Roosevelt Lake, ending by 1970. Scarce information exists on Arizona buffalofishes since.
From 2018 to 2023 we studied buffalofishes from nearby Apache Lake (adjacent and downstream of Roosevelt Lake) in collaboration with anglers. Here we show that more than 90% of buffalofishes captured from Apache Lake are more than 80 years old and that some of the original buffalofishes from the Arizona stocking in 1918 are likely still alive. Using unique markings on old-age buffalofishes, we demonstrate how individuals are identified and inform dozens of recaptures. With a sample size of only 23 individuals across the three species of buffalofishes at Apache Lake, we found direct evidence of centenarian longevity for black buffalo (108 years), bigmouth buffalo (105 years), and smallmouth buffalo (101 years).
We now know all species of USA Ictiobus can live more than 100 years, making it the only genus of animal besides marine rockfishes (Sebastes) for which three or more species have been shown to live more than 100 years. Our citizen-science collaboration has revealed remarkable longevity for freshwater fishes and has fundamentally redefined our understanding of the genus Ictiobus itself.