Bigmouth buffalo: Mysterious fish that live a century and doesn’t age

Recent discoveries show that Bigmouth buffalo, a freshwater fish, has an incredibly long life and seems to be getting healthier with age. However, scientists are concerned that his population may be endangered.

If you ever reach the banks of the Rice Lake in Minnesota in May, you might notice large swarms of fish mingling among wild rice plants in waters just a few metres deep. These are bivoli bigmouth, the longest freshwater fish in the world. Some people live over 100 years.

Each year, these huge fish, which can weigh more than 23 kg, migrate to the Rice River to lay their eggs in the lake. However, despite this annual reproductive process, for over six decades no young fish have matured in this area.

An ignored but amazing species

The bigmouth buffalo is native to North America, being found from southern Canada to the south of the United States. Over time, these fish have been underestimated as “common fish ‘, i.e. species without commercial value or scientific interest. It is only in the last five years that scientists have begun to understand how unique these fish are.

Some specimens have been documented as up to 127 years old, setting the record for the longest freshwater fish. Moreover, research has shown that they do not appear to show signs of biological ageing.

A threatened population

Research in Lake Rice has shown that most fish in this area are extremely old. 99.7% of the fish analysed were over 50 years old and the median age was 79. However, despite their annual reproduction, no young people survive after the summer.

One possible factor for this situation is the intense prey by young pikes, who lay their eggs earlier in the same lake. The extreme longevity of the bigmouth buffalo may be an adaptation to the low survival rate of the offspring.

The mystery of longevity

Recent research looked at indicators of biological ageing, such as telomeric length and immune cell ratios. The results suggest that older fish not only don’t age, they do seem to be getting healthier. For example, they have a more effective immune system with age.

Challenges for conservation

Despite their longevity, bivoli bigmouth populations are vulnerable. There are no clear protective measures for this species and overfishing, especially by the bowfishing method, contributes to their decline.

Lack of research also makes it difficult to understand their biological and ecological needs. Researchers do not know where these fish migrate outside the breeding season or what other populations might be affected.

Bigmouth buffalo is a fascinating example of hidden biodiversity in freshwater. Their unique longevity and health provide clues to the mechanisms of aging, but time to understand and protect this species is limited. If no action is taken quickly, we risk losing a species with valuable biological secrets.

Source:bbc.com• Photo: bbc.com