Adaptive Longevity: Desert Fish Species Discovered to Live for 100 Years

Sunday - November 5 2023, 01:17 UTC - 1 year ago

A University of Minnesota study on fish species located in the Apache Lake reservoir in Arizona's desert region revealed that some species of the buffalofish have lifespans of over 100 years. To determine the age of the buffalofish, the team extracted "earstones" from within the fish's skull, which are stone-like structures that develop a new layer each year. Anglers noticed and alerted researchers of unusual orange and black spots on the buffalofish which triggered the study, and the team concluded that species of the buffalofish introduced to Arizona in 1918 are most likely still alive today.

An unexpected secret has emerged amid the blistering heat of the Arizona desert, where survival appears to be a relentless fight against nature's harsh conditions. Surprisingly, some of the oldest species have been discovered living in this unlikely location – fish with lifespans reaching a mind-boggling 100 years. Fish may be found in the desert region's oases, springs, and other bodies of water, often in isolated and specialized settings that have allowed them to adapt to the rough desert environment .

This University of Minnesota study was focused on fish species located in the Apache Lake reservoir in the southwest of the Arizona desert, namely bigmouth buffalo, smallmouth buffalo, and black buffalo. These species are members of the genus Ictiobus. "There is likely a treasure trove of aging, longevity, and negligible senescence information within the genus Ictiobus," Alec Lackmann, an ichthyologist, and one of the study authors, said in an official release .

Lackmann further added: "This study brings light to this potential and opens the door to a future in which a more complete understanding of the process of vertebrate aging can be realized, including for humans. The research begs the question: what is the buffalofishes’ fountain of youth?"How the fish age was determined? To determine the age of these buffalofishes, the study team extracted otoliths, commonly known as earstones, from within the fish's skull .

Otoliths are tiny, stone-like structures that develop continually throughout the life of the fish, adding a new layer each year. Scientists can measure the age of the fish by analyzing the otolith using a compound microscope and counting the layers much like the rings of a tree. The findings revealed that some of the original buffalofishes introduced to Arizona in 1918 are most likely still alive today .

"Originally reared in hatcheries and rearing ponds along the Mississippi River in the Midwest, the government stocked buffalofishes into Roosevelt Lake (upstream of Apache Lake), Arizona in 1918," mentioned the release. Roosevelt Lake was commercially fished over the course of time, but the fish populations in Apache Lake remained relatively unaffected. Anglers just recently found efficient ways for capturing buffalofish in Apache Lake using rod and line .

Unusual orange and black spots on the fish prompted this study. Some conservation fishermen who practice catch-and-release began to notice unusual orange and black spots on the fish they were capturing, which piqued their interest and prompted additional research into these patterns. They approached Lackmann to conduct a scientific analysis of certain fishes, ultimately unraveling the remarkable longevity of these freshwater fish species that call the desert home .

The team highlights that "such longevity across multiple freshwater fish species is found nowhere else in the world." "These long-lived species of fishes and individuals could be monitored so that we can further study and understand their DNA, their physiology, their ability to fight infection and disease, and to compare these systems across the continuum of age," said Laackmann.