Fish
Bigmouth Buffalo
Ictiobus cyprinellus · also called gourdhead, redmouth buffalo
For a century, the bigmouth buffalo was written off as a short-lived trash fish. Then someone dated its ear bones, and it turned out that the drab, carp-like fish being shot at night for sport can be older than the state it swims in.
Overview
Ictiobus cyprinellus is the largest sucker in North America, native to the Mississippi, Missouri, Ohio, and Hudson Bay drainages, in slow rivers, backwaters, and shallow lakes. It is a filter feeder, straining zooplankton and small invertebrates from open water and sediment. Despite the resemblance it is not a carp — it has no barbels and is a native species.
The oldest bony fish
A 2019 study dated the otoliths of Minnesota buffalo and found many fish over 80 years old, several past 100, and one at about 112 — far beyond the 26 years biologists had assumed, and older than any other bony fish on record.
An ageing population
In some lakes nearly every buffalo is decades old, with successful spawning only in occasional wet springs. A population can look healthy while failing to replace itself, and the oldest fish are still killed in unlimited numbers by bowfishing.
Status
Officially Least Concern, but that predates the longevity findings. Scientists are calling for it to be managed like the long-lived fish it is.
Bigmouth Buffalo: common questions
How old can a bigmouth buffalo really get?
Older than any other bony fish yet measured. For most of the twentieth century biologists believed the species lived around 25 years, based on counting rings in scales, which is unreliable in old fish. In 2019 researchers dated the otoliths, the fish's ear stones, using a bomb-radiocarbon method calibrated against nuclear testing in the 1950s, and found that in several Minnesota lakes the majority of bigmouth buffalo were over 80 years old, with individuals of 99, 102, 108, and about 112 years. That makes the bigmouth buffalo the oldest-known freshwater bony fish, in the same league as some sturgeon and rockfish.
How do I tell a bigmouth buffalo from a common carp?
The quickest check is the mouth. A common carp has two pairs of fleshy whiskers, called barbels, at the corners of its mouth; a bigmouth buffalo has none. The carp also has a long dorsal fin running much of the length of its back with a stout serrated spine at the front, while the buffalo's dorsal fin is shorter and has no spine. Carp scales often have a brassy or golden sheen and the fish frequently shows reddish or orange fins; the buffalo is a plainer slate-grey to bronze. Both are big, deep-bodied fish in murky water, which is why the mix-up is so common.
Is the bigmouth buffalo endangered?
It is currently listed as Least Concern, and across its whole range it is still widespread. But that status was assigned before scientists understood how the species lives. A fish that can reach 100-plus years, that in some lakes has not successfully bred for decades, and whose oldest individuals are being removed in large numbers by unregulated bowfishing is exactly the kind of species that can collapse suddenly after looking fine for a long time. Several researchers now argue the bigmouth buffalo should be reclassified and managed with the caution given to sturgeon.
Why is it called a buffalo?
The name most likely comes from the fish's high, humped back and heavy shoulders, which suggested the profile of an American bison, or buffalo, to early settlers on the rivers of the Midwest and South. There are three buffalo species, the bigmouth, the smallmouth, and the black, all in the sucker family and all native to central North America. They were an important food fish for Indigenous peoples and for nineteenth and early twentieth century river communities, and bigmouth buffalo is still sold commercially, often smoked.